Accepted Manuscript Immediate Effects of Repetitive Wrist Extension on Grip Strength in Patients with Distal Radial Fracture Msahiro Mitsukane, MS, OTR Noboru Sekiya, PhD, RPT Sayaka Himei, OTR Koji Oyama, MD PII:
S0003-9993(14)01131-9
DOI:
10.1016/j.apmr.2014.09.024
Reference:
YAPMR 55990
To appear in:
ARCHIVES OF PHYSICAL MEDICINE AND REHABILITATION
Received Date: 19 June 2014 Revised Date:
11 September 2014
Accepted Date: 18 September 2014
Please cite this article as: Mitsukane M, Sekiya N, Himei S, Oyama K, Immediate Effects of Repetitive Wrist Extension on Grip Strength in Patients with Distal Radial Fracture, ARCHIVES OF PHYSICAL MEDICINE AND REHABILITATION (2014), doi: 10.1016/j.apmr.2014.09.024. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Running head: Grip Strength after Distal Radial Fracture
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Ms. Ref. No. : ARCHIVES-PMR-D-13-00843
Title: Immediate Effects of Repetitive Wrist Extension on Grip Strength in Patients
Author: Msahiro Mitsukane, MS, OTR
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1st)
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with Distal Radial Fracture
Department of Occupational Therapy, School of Health Sciences, Tokyo University of Technology, Tokyo, Japan 2nd)
Noboru Sekiya, PhD, RPT
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Department of Physical Therapy, School of Nursing and Rehabilitation Sciences, Showa University, Yokohama, Kanagawa, Japan 3rd)
Sayaka Himei, OTR
Japan
Koji Oyama, MD
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4th)
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Department of Rehabilitation Medicine, Fujisawa Shounandai Hospital, Kanagawa,
Department of Orthopedic Surgery, Fujisawa Shounandai Hospital, Kanagawa, Japan
Data collection was performed at the Department of Rehabilitation Medicine, Fujisawa Shounandai Hospital, Kanagawa, Japan.
There are no acknowledgments of presentation of this material. 1
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There are no acknowledgments of financial support.
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There are no conflicts of interest.
Corresponding author (as the author from whom reprints can be obtained): Masahiro Mitsukane, Ms, OTR Department of Occupational Therapy,
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School of Health Sciences, Tokyo University of Technology
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Email: [email protected]
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5-23-22 Nishikamata, Ohta-ku, Tokyo 144-8535 Japan
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Immediate Effects of Repetitive Wrist Extension on Grip Strength in Patients with Distal
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Radial Fracture
3 4 Abstract
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Objective: To evaluate the immediate effect of repetitive wrist extension on grip strength in
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patients with distal radial fracture.
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8 Design: Interventional study.
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Setting: Patients who were admitted to the Department of Occupational Therapy, Hospital in ○○.
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Participants: Twenty-eight consecutive patients with a unilateral distal radial fracture participated
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in this study.
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Intervention: Each patient was randomly allocated to either the experimental (n = 14) or control
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group (n = 14). The experimental group performed 30 repetitive wrist extensions with maximal
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isometric contraction of the extensors of their affected hands during a 6-min intervention period,
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whereas the control group did not perform the exercise.
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Main Outcome Measures: Grip strength was measured just before and after the intervention
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period. Pain during grip strength measurements was also quantified using the visual analogue
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scale (VAS). Wrist extension strength was measured 10 min after the grip strength measurement.
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Results: Grip strength increased immediately after repetitive wrist extension in the experimental
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group, but it remained the same in the control group. VAS scores indicated that pain was relieved
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only in the experimental group. However, pain was unrelated to strength production.
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Conclusion: The intervention used in this study might be useful during physical examination to 1
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reveal the potential grip strength of patients. The intervention may also be an effective warm-up
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training procedure in preparation for conventional grip-strengthening exercises.
3 4 Key Words: Radius fracture; Hand strength; Rehabilitation; Wrist joint.
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Abbreviations: DRF (distal radial fracture); OT (occupational therapy); VAS (visual analogue
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scale).
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The decrease in grip strength after distal radial fracture (DRF) makes it difficult for patients to use
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their hands for many daily activities
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rehabilitation. However, clinical treatment outcomes of DRF patients have not necessarily been
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satisfactory
3)–6)
1), 2)
, and recovery from this weakness is a major goal of
.
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Numerous researchers have examined the relationships between treatment outcome in terms of
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grip strength, the initial orthopedic treatment procedure, and radiographic examination findings
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7)–12)
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restoration of grip strength after DRF. Several authors reported that an early initiation of therapy
3),
13)–17)
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, but few studies have determined an effective occupational therapy (OT) treatment for the
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after injury results in a rapid recovery of grip strength
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to clarify what types of exercise are optimal for the quick recovery of or increase in grip strength
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after DRF.
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. However, further studies are required
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18)
The wrist should be stabilized by wrist extensors at a fixed position during the grasp , at
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approximately 30° of wrist extension to achieve a powerful grip
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have to exert sufficient force to stabilize the wrist joint in the position . Patients with DRF may
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not be able to exert enough grip strength that corresponds to wrist extension strength. We
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previously reported that the strength of wrist extensors highly correlated with grip strength in both
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the affected and unaffected sides of DRF patients, and the decrease in grip strength on the affected
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side was greater than the value predicted from a regression equation for the unaffected side. In
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addition, stabilization of the wrist joint with a splint immediately improved grip strength on the
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affected side . These results suggest that DRF patients were not able to demonstrate their
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potential grip strength because of their inability to exert sufficient force to stabilize the wrist.
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Furthermore, treatment of acute DRF with a cast or surgical instruments commonly restricts wrist
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motion, and muscle disuse due to constriction may decrease muscle activation. Several studies
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showed that muscle disuse reduced muscle activation level.
19)–22)
. Therefore, wrist extensors 23)
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25), 26)
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Asano et al. reported that DRF patients produced their maximum grip strength at later trials of
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ACCEPTED MANUSCRIPT 30 consecutive measurements for 6 min, whereas healthy subjects demonstrated their maximum
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grip strength in the first trial. These researchers suggested that the results in DRF patients might
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be related to pain and/or the scar formation in the surrounding tissues of the fracture site. However,
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we hypothesized that the results might be related to the reduced activation of wrist extensors
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during the early trials, which might be improved through repetitive wrist extension exercises. This
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hypothesis is based on our clinical experiences and the facts that grip strength tests involve an
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isometric contraction of wrist extensors, and muscle activation can be enhanced by voluntary
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contractions28). If these assumptions are correct, repetitive isometric contractions of these muscles
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could lead to an immediate increase in grip strength in DRF patients. This procedure might be
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useful in the examination of the potential grip strength of patients, and it might also be effective in
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the treatment for the restoration of weakened grip strength. Therefore, the purpose of this study
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was to clarify the effects of repetitive isometric contraction on grip strength in DRF patients.
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Methods
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Participants
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Consecutive patients who were admitted between June and November 2011 to the Department of
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Rehabilitation Medicine at ○○ Hospital for treatment of DRF were included in the present study.
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Participants attended the experiment after they had begun their passive range-of-motion exercises.
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The following exclusion criteria were used: (1) a history of a disease or other injuries that weaken
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the upper extremities; (2) a complication of complex regional pain syndrome, carpal tunnel
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syndrome, or tendon rupture after injury; (3) difficulty in understanding instructions because of
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cognitive disorders such as dementia; (4) inability to move the affected wrist to more than 0° of
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flexion and/or 30° of extension; and (5) bilateral injury.
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The research ethics committee of the School of Nursing and Rehabilitation Sciences at ○○ 4
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University (approval no. 149) and the bioethics committee of ○○ Hospital approved the present
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study.
3 Forty-four DRF patients were selected for the study, one of whom met an exclusion criterion and
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was excluded. Twenty-eight of the remaining 43 patients agreed to participate in the study. Written
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informed consent was obtained from all of the participants. The mean age of the participants was
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63 ± 13.0 years (range, 27–81 years). Fractures were reduced at a mean of 5.8 ± 6.8 days (range,
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0–22 days) after injury, and OT was initiated at a mean of 31.5 ± 12.4 days (13–54 days) after
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injury. The treatment period mean was 69.6 ± 74.7 days (range, 3–301 days). In the initial
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orthopedic treatments, 11 patients were treated conservatively with casts, and 17 patients
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underwent surgery for fixation of the fracture. In the patients treated with casts, fractures were
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reduced at a mean of 0.2 ± 0.4 days (range, 0–1 day) after injury, and OT was started a mean of
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44.8 ± 4.9 days (36–54 days) after injury. In the patients treated with surgery, fractures were
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reduced at a mean of 9.5 ± 6.4 days (0–22 days) after injury, and OT was started a mean of 22.7 ±
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6.3 days (13–35 days) after injury.
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The definitions of the radiographic examination results (mean ± SD, range) were as follows: mean
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dorsal angulation (−2.6° ± 14.1°, −43° to 12°), the angle measured on the lateral radiograph
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between a line perpendicular to the long axis of the radius and the articular surface indicated by a
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line joining the volar and dorsal margins of that surface ; mean radial inclination (21.0° ± 5.0°,
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11–28°), the angle measured on the frontal radiograph between a line perpendicular to the long
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axis of the radius and the radial articular surface indicated by a line joining its radial and ulnar
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margins ; and mean radial shortening (0.8 ± 2.9 mm, −5 to 6 mm), measured on the frontal
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radiograph as the vertical distance between the distal end of the ulna and medial corners of the
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30) radius .
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Study protocol
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Fig. 1 shows the experimental procedures. Every 2 consecutive patients were randomly allocated 5
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either to the experimental or control group.
2 At first, measurements of grip strength and the visual analogue scale (VAS) of pain were
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performed for each of the participants (pretest). Just after these measurements, participants in the
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experimental group underwent repetitive wrist extensions only with their affected side during a
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6-min intervention period, whereas control group participants were allowed a 6-min rest. Just after
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the intervention period, the grip strength and pain were measured as described in the pretest.
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The wrist extension strength of both hands was measured in all of the participants 10 min after the
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grip strength measurement. All of the measurements were conducted in each patient before their
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routine exercise.
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Repetitive wrist extension
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Participants held a lightweight rod (approximately 5 g; diameter, 1 cm; length, 20 cm) gently with
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their affected hand to keep their finger joints flexed during repetitions of wrist extension.
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Participants moved their wrists quickly up to the position of full extension and maintained
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isometric contractions for 3 s with maximum effort. Subsequently, they rested for 3 s, keeping the
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wrist relaxed. This combination of contraction and relaxation was repeated 10 times for 1 min,
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followed by a 1-min rest period. This sequence was repeated 3 times. Therefore, 30 repetitions of
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wrist extensions were performed for 6 min. This protocol was decided with reference to Asano et
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al. Participants were encouraged by the occupational therapist to give their maximum effort
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during each trial.
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Grip strength measurement
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Grip strength was measured with a Jamar Digital Hand Dynamometera. The grip handle was
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adjusted to the position of the second narrowest width between the bars. The hand dynamometer
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was calibrated once before all of the data were collected. 6
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the shoulders neutral, elbows at 90° flexion, and forearms neutral in supination/pronation.
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Participants held the dynamometer without any assistance or support, and they were instructed to
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clutch it under maximum effort. Two trials were performed for each measurement, and the higher
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value was adopted. The measurement order of the affected and unaffected sides was randomized
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for each subject.
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Pain was measured using VAS just after each grip strength measurement. The VAS for pain
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consists of a 100-mm-long horizontal line with “no pain” at the left end and “worst pain” at the
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right end. Values (in millimeters) were recorded from the left end of the line. The average of 2
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trials was used as the VAS data that corresponded to each grip strength measurement.
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Measurement of wrist extension strength
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The isometric strength of wrist extensors was measured using a handheld dynamometer
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(µTasMT-1b). The measurement order of the left and right sides was randomized for each
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participant. Fig. 2 shows that measurements were performed while the participant was in a sitting
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position with the forearm placed on a table, the elbow flexed at approximately 90°, the arm
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pronated, and the wrist positioned at 30° of extension. A dynamometer pad was placed on the
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dorsal surface of the hand with the distal edge of the pad set just proximal to the third
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metacarpophalangeal joint. The midline of the pad was set along the long axis of the third
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metacarpal bone. Participants held a lightweight rod (previously described) while the hand was
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examined, and they were instructed to exert maximal wrist extension for 5 s. Each measurement
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was performed twice, and the higher value was adopted.
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ACCEPTED MANUSCRIPT Statistical analysis
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The Mann-Whitney test was used for between-subject comparisons, and Wilcoxon signed rank test
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was used for within-subject comparisons. Fisher’s exact test was used for categorical variables.
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Two-way analysis of variance was not performed because the statistical prerequisite of normality
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of error and/or homogeneity of error variance was not fulfilled with the data obtained. The
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Spearman rank correlation coefficient was used to clarify the relationship between grip strength
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and wrist extension strength. The significance level was set at 0.05, and 2-tailed tests were
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performed. Statistical calculations were performed using the textbook of Sigel et al. 31) (Wilcoxon
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signed rank test) and IBM SPSS Statistics 21c (other than Wilcoxon signed rank test).
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Table 1 shows the demographic data of the experimental and control groups, each with 14
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participants. Differences between the 2 groups were not significant (p > 0.05) in any of the
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parameters (age, sex, affected side, type of initial treatment, time to fracture reduction, time to the
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start of OT, OT duration, radiographic examination, grip strength, or strength of the wrist
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extensors), although the p value for radial inclination was almost significant.
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Table 2 shows the grip strength just before and after the intervention period. The grip strength on
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the affected side increased significantly after the intervention only in the experimental group (n =
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10, T- = 1, p = 0.01). Grip strength on the unaffected side also increased significantly after the
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intervention period only in the experimental group (n = 10, T- = 8.5, p = 0.05).
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Table 3 shows the VAS scores. No significant difference in the baseline pain score on the affected
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side was found between the experimental and control groups (na = 13, nb = 13, U = 62.5, p = 0.23).
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Pain on the affected side decreased after the intervention in the experimental group, whereas no
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significant difference was observed between pretest and posttest pain in the control group.
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However, the Spearman rank correlation coefficient between changes in pain and grip strength in
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the experimental group was 0.29 (p = 0.47), which shows that pain decrease might not be the 8
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cause of the grip strength increase.
2 Table 4 and Fig. 3 show the relationship between grip strength and wrist extension strength.
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Significant and considerably high correlations were found in both groups in all of the conditions.
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Fig. 3 illustrates the relationship through scatter plots and estimated fitted lines. The filled and
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unfilled circles represent the affected side of the experimental and control groups, respectively.
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The filled and unfilled triangles represent the unaffected side of the experimental and control
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groups, respectively. A strong linear correlation was observed between wrist extension strength
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and grip strength even when ensemble data (all conditions and both groups) were used. These
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results indicate that grip strength production in the DRF patients was strongly dependent on wrist
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extensor strength across a wide range.
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Discussion
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Immediate effects of repetitive wrist extension on grip force
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This study examined the effects of repetitive wrist extension on grip strength in DRF patients. The
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results indicated that grip strength on the affected side was increased through the intervention in
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the experimental group, but not in the control group. This result suggests that repetitive wrist
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extension enhanced muscle activation of wrist extensors during a grasp, whereby patients were
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able to exert their maximal grip strength. Several studies indicated
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exert sufficient force to stabilize the wrist joint at approximately 30° of extension to achieve a
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powerful grip. If patients could not exert the requisite wrist force for a powerful grip, their grip
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strength would be less than their maximum. Therefore, the performing of repetitive wrist
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extensions before grip strength assessments could potentially increase maximal grip strength
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measurements in DRF patients. Furthermore, this procedure might be effective as warm-up
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training before conventional grip strengthening exercises.
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18),19)–22)
that wrist extensors must
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ACCEPTED MANUSCRIPT Several mechanisms have been proposed for increased muscle force due to repetitive movements.
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Girard et al. 28) reported that running- or strength-based warm-up exercises increased maximum
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voluntary knee extension torque and knee extensor muscle activation, which suggests direct
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effects of voluntary exercises on muscle activation and contraction. Meanwhile, Ranatunga et al.32)
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examined the influence of temperature on the contraction characteristics of the first dorsal
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interosseus and showed that the maximal twitch tension decreased approximately 50% when
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cooled from 35–12℃. De Ruiter et al.33) also showed that force generation by the human adductor
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pollicis muscle decreased with a decrease in lower-arm temperature (36.8–22.3℃). These results
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suggest that repetitive muscle contractions may have a direct and/or secondary effect on muscle
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activation and contraction via an increase in muscle temperature.
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Our results also showed that grip strength on the unaffected side increased in the experimental
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group but not in the control group, which suggests that so-called cross-training effects34) may have
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occurred in the present study. These results and increase in muscle activation described earlier
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suggest that the upper-level neural control of force generation may have changed because of the
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repetitive muscle contraction.
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VAS scores in the present study suggest that the pain in the affected wrist was relieved through
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repetitive wrist extension. Asano et al. suggested that repetitive gripping increased the grip force
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of DRF patients, probably because of the decrease in pain in the injured area through repetitive
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wrist extensions. Pain in the injured area in the present study decreased during the intervention
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period only in the experimental group, as Asano et al. also inferred. However, a relationship
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between pain and grip strength increase was not demonstrated in the present study. Therefore, we
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could not conclude that pain reduction increased grip force in patients with DRF. Based on the
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duration from injury onset and the fact that patients underwent OT, the pain measured in the
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present study might be caused by immobilization during treatment of the injury rather than by the
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fracture per se
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area and decrease pain-inducing substances. Recently, several research studies indicated that
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therapeutic exercises reduced chronic pain . The results in the present study also suggest
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35), 36)
. The repetitive wrist extension exercise might improve ischemia in the injured
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immediate effects of repetitive muscle contractions with vigorous intensity.
2 3 Strong, wide-range linear relationship between grip and wrist extension strength in DRF
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patients
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As mentioned in the Introduction, we previously reported24) that the strength of the wrist extensors
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highly correlated with grip strength on the affected and normal sides of DRF patients and the grip
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strength of the affected side decreased more than the value predicted from the wrist extensor
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strength using a regression equation of the normal side. Furthermore, wrist joint stabilization with
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a splint immediately improved grip strength on the affected side; however, the improvement was
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less than the value predicted from the regression line of the normal side. Wrist joint fixation with a
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splint on the normal side conversely weakened grip strength. These results suggest that the
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optimal wrist angle for maximum gripping tasks varies according to individual subjects.
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The present study also found a strong, wide-range relationship between grip and wrist extension
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strength in DRF patients (Fig. 3). We did not measure wrist extension strength before the
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intervention. Therefore, we indicated only the results of the post-intervention measurements. The
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highly consistent and linear relationship might show that the participants fixated their wrist joints
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at their own optimal angle in contrast to cases in which a splint was used for fixation. This strong
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relationship between grip strength and wrist extension strength suggests that an increase in grip
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strength is strongly constrained by wrist extension strength. Finger flexors could not produce their
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potential muscle strength more than the magnitude corresponding to the wrist extension force.
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Our results also suggest the presence of a relationship that is useful for the prediction of recovery
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from decreased grip strength. Assuming that the relationship between grip and wrist extension
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strength is optimal, when a point for a specific patient in Fig. 3 is plotted lower and farther away
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from the line representing optimal “wrist extension to finger flexion” relationship, the finger
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flexors of the patient should be weak relative to wrist extensor strength. In contrast, when a point
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is very close to the line, the finger flexors would match wrist extensors or the wrist extensors 11
ACCEPTED MANUSCRIPT would be weak relative to the finger extensors. In the latter case, enhancing the wrist extensor
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might immediately improve grip force. However, we could not conclude that this relationship
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existed in the present study because we did not measure wrist extension strength before the
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intervention. Further studies are needed to clarify this problem. At any rate, detailed investigations
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on the relationship between wrist extension and grip strength are important to provide insight for
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the rehabilitation of patients with DRF and likely other patients with gripping function problems.
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This study had several limitations. First, we did not measure wrist extension strength before the
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intervention or the angle of wrist joint chosen by participants. Second, statistical analyses were not
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optimal for the experimental design because the statistical prerequisites were not met, and
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nonparametric 2-group comparisons were performed. A study with a larger sample may solve this
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problem. Furthermore, the selection of interventional movements, movement intensity, and the
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number of iterations should be reviewed and optimized.
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14 15 Conclusions
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This study suggests that repetitive maximal wrist extension is useful in physical examinations to
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reveal the maximal grip force of patients with DRF, and it is effective as a warm-up training
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procedure in preparation for conventional grip strength exercises.
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force and grip strength after fractures of the distal radius. Gen Rehabil [Japanese] 2005; 33:
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Mitsukane M, Mina M, Yamaguchi A, Saito K. The relationship between wrist extension
Berg HE, Larsson L, Tesch PA. Lower limb skeletal muscle function after 6 wk of bed rest. J Appl Physiol 1997; 82:182-8.
27)
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Asano A, Kato K, Chikama S. Consideration of the variation in grip measurements of 30 times repetitions after fracture of the distal radius. Seikeigekarehabilitationgakkaishi
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[Japanese] 2008; 11: 48-51. 28)
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Girard O, Carbonnel Y, Candau R, Millet G. Running versus strength-based warm-up: Acute effects on isometric knee extension function. Eur J Appl Physiol 2009;106: 573-81.
29)
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Van der Linden W, Ericson R. Colles’ fracture: How should its displacement be measured and how should it be immobilized? J Bone Joint Surg [Am] 1981; 63-A: 1285-8.
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30) Melone CP Jr. Articular fractures of the distal radius. Orthop Clin North Am 1984; 15:
23 24 25 26 27 28 29
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217-36.
31) Siegel S, Castellan NJ Jr. Nonparametric Statistics for the Behavioral Sciences. 2nd ed. Boston: McGraw-Hill Book; 1988. 32) Ranatunga KW, Sharpe B, Turnbull B. Contractions of a human skeletal muscle at different temperature. J Physiol 1987; 390: 383-95. 33) De Ruiter CJ, De Haan A. Temperature effect on the force/velocity relationship of the fresh and fatigued human adductor pollicis muscle. Pflugers Arch 2000; 440: 163-70. 14
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34) Farthing JP, Chilibeck PD, Binsted G. Cross-education of arm muscular strength is
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unidirectional in right-handed individuals. Med Sci Sports Exerc 2005;37:1594-600.
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35) Ushida T, Willis WD. Changes in dorsal horn neuronal responses in an experimental wrist
5 6 7
contracture model. J Orthop Sci 2001; 6: 46-52. 36) Galer BS, Jensen M. Neglect-like symptoms in complex regional pain syndrome: Results of
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a self-administered survey. J Pain Symptom Manage 1999; 18: 213-7.
37) Chou R, Qaseem A, Snow V, et al. Diagnosis and treatment of low back pain: A joint clinical practice guideline from the American College of Physicians and the American Pain Society.
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Ann Intern Med 2007; 147: 478-91.
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11 Suppliers
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a. Jamar Plus+ Digital Hand Dynamometer, Sammons Preston USA1000 Remington Blvd Suite
14
210 Bolingbrook, IL 60440-5117 United States
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b. µTas MT-1, Anima Corporation, Tokyo, Japan
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c. IBM SPSS Statistics 21, IBM Japan, 19-21 Hakozaki, Nihonbashi, Chuo-ku, Tokyo 103¥8510
17
Japan
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19 Figure Legends
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Fig 1: The study protocol.
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Fig 2: Measurement of wrist extension strength using a handheld dynamometer.
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Fig 3: The relationship between grip strength and wrist extension strength in all of the subjects.
26
Grip strength after the intervention period was used as the independent variable.
27
15
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Experimental Group
Control Group
U
p 0.5
5(35.7) 9(64.3) 62±13
4(28.6) 10(71.4) 64±14
85.5
0.57 0.35
9(64.3) 5(35.7)
7(50) 7(50)
6(42.9) 7(50) 1(7.1) 5.0±6.7 31.1±12.3 66.4±86.9
5(35.7) 9(64.3) 0(0) 6.6±6.9 31.9±13.0 72.9±63.3
0.41 0.85 0.41
-1.4±14.0 19.1±5.0 1.0±3.3
103 138 86.5
0.82 0.07 0.6
30.4±16.4 15.0±8.9
29.9±10.2 15.0±8.5
84 91
0.54 0.77
18.1±8.0 11.4±4.3
16.8±4.3 10.7±3.1
90.5 103
0.7 0.8
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80.5 94 80
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-3.8±14.6 22.9±4.4 0.6±2.6
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Sex Male n(%) Female n(%) Age, yr (mean±SD) Affected hand Dominant n(%) Non-dominant n(%) Initial treatment Cast immobilization n(%) Open reduction and internal fixation n(%) External fixation n(%) Fractures were reduced (days after trauma) mean±SD Rehabilitation started (days after trauma) mean±SD Duration of rehabilitation, (day) mean±SD Anatomical results Dorsal angulation, (degree) mean±SD Radial inclination, (degree) mean±SD Radial shortenning, (mm) mean±SD Grip strength Unaffected side, (㎏) mean±SD Affected side, (㎏) mean±SD Force of wrist extensors Unaffected side, (㎏) mean±SD Affected side, (㎏) mean±SD
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ACCEPTED Table 1: Characteristics of subjectsMANUSCRIPT in the experimental and control groups
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Table 2: Changes of grip strength during the intervention period (Kg)
Time of measurement Post
T-
Experimental group
15.0±8.9
16.4±9.9
1
Control group
15.0±8.5
15.3±8.2
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Unaffected side
Time of measurement
p value
Pre
Post
T-
p value
0.01
30.4±16.4
31.0±16.5
8.5
0.05
0.26
29.9±10.2
28.8±8.3
30
0.28
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Pre
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Affected side
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Table 3: Changes of the VAS for pain (mm) Time of measurement Pre Post
T-
p value
0
0.03
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Experimental group Affected side
9.4±21.8
2.3±5.1
Unaffected side
0.0±0.0
0.0±0.0
Affected side
18.2±25.4
13.3±23.0
5
0.13
Unaffected side
0.69±2.21
1.23±3.75
0
0.18
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Control group
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Note. Score of 0 indicates "No pain"and score of 100 indicates "Maximum pain".
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Affected side Time of measurement Pre Post 0.73 **
0.79 **
Control group
0.94 **
0.94 **
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Note. Values are Spearman’s rank correlation coefficient ** p < 0.01
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Unaffected side Time of measurement Pre Post
0.87 **
0.86 **
0.87 **
0.7 **
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Experimental group
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Table 4: The relation between the grip strength and the wrist extension strength (rs )
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Every 2 consecutive patients
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Random allocation
Control group
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Experimental group Unaffected limb
Measurement of grip (2 trials ) and VAS
Measurement of grip (2 trials ) and VAS
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Measurement of grip (2 trials ) and VAS
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Measurement of grip (2 trials ) and VAS
Measurement of grip (2 trials ) and VAS
Unaffected limb
Measurement of grip (2 trials ) and VAS
６ minutes intermission
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Repetition of wrist extension
Affected limb
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Affected limb
Measurement of grip (2 trials ) and VAS
Measurement of grip (2 trials ) and VAS
Intermission for more than 10 minutes
Measurements of wrist extension strength : 2 trials
Fig １.
Measurements of wrist extension strength : 2 trials
Measurements of wrist extension strength : 2 trials
Measurements of wrist extension strength : 2 trials
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Fig 2.
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50
40
Affected side of experimental group Unaffected side of experimental group Affected side of control group Unaffected side of control group
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30
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0 0
5
10
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Grip strength (Kg)
80
15
20
25
30
35
40
Strength of dorsal-flexors (Kg) Fig 3.
S0003-9993(14)01131-9
DOI:
10.1016/j.apmr.2014.09.024
Reference:
YAPMR 55990
To appear in:
ARCHIVES OF PHYSICAL MEDICINE AND REHABILITATION
Received Date: 19 June 2014 Revised Date:
11 September 2014
Accepted Date: 18 September 2014
Please cite this article as: Mitsukane M, Sekiya N, Himei S, Oyama K, Immediate Effects of Repetitive Wrist Extension on Grip Strength in Patients with Distal Radial Fracture, ARCHIVES OF PHYSICAL MEDICINE AND REHABILITATION (2014), doi: 10.1016/j.apmr.2014.09.024. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Running head: Grip Strength after Distal Radial Fracture
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Ms. Ref. No. : ARCHIVES-PMR-D-13-00843
Title: Immediate Effects of Repetitive Wrist Extension on Grip Strength in Patients
Author: Msahiro Mitsukane, MS, OTR
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1st)
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with Distal Radial Fracture
Department of Occupational Therapy, School of Health Sciences, Tokyo University of Technology, Tokyo, Japan 2nd)
Noboru Sekiya, PhD, RPT
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Department of Physical Therapy, School of Nursing and Rehabilitation Sciences, Showa University, Yokohama, Kanagawa, Japan 3rd)
Sayaka Himei, OTR
Japan
Koji Oyama, MD
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4th)
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Department of Rehabilitation Medicine, Fujisawa Shounandai Hospital, Kanagawa,
Department of Orthopedic Surgery, Fujisawa Shounandai Hospital, Kanagawa, Japan
Data collection was performed at the Department of Rehabilitation Medicine, Fujisawa Shounandai Hospital, Kanagawa, Japan.
There are no acknowledgments of presentation of this material. 1
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There are no acknowledgments of financial support.
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There are no conflicts of interest.
Corresponding author (as the author from whom reprints can be obtained): Masahiro Mitsukane, Ms, OTR Department of Occupational Therapy,
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School of Health Sciences, Tokyo University of Technology
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Email: [email protected]
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5-23-22 Nishikamata, Ohta-ku, Tokyo 144-8535 Japan
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Immediate Effects of Repetitive Wrist Extension on Grip Strength in Patients with Distal
2
Radial Fracture
3 4 Abstract
6
Objective: To evaluate the immediate effect of repetitive wrist extension on grip strength in
7
patients with distal radial fracture.
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8 Design: Interventional study.
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Setting: Patients who were admitted to the Department of Occupational Therapy, Hospital in ○○.
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Participants: Twenty-eight consecutive patients with a unilateral distal radial fracture participated
14
in this study.
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Intervention: Each patient was randomly allocated to either the experimental (n = 14) or control
17
group (n = 14). The experimental group performed 30 repetitive wrist extensions with maximal
18
isometric contraction of the extensors of their affected hands during a 6-min intervention period,
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whereas the control group did not perform the exercise.
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Main Outcome Measures: Grip strength was measured just before and after the intervention
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period. Pain during grip strength measurements was also quantified using the visual analogue
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scale (VAS). Wrist extension strength was measured 10 min after the grip strength measurement.
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Results: Grip strength increased immediately after repetitive wrist extension in the experimental
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group, but it remained the same in the control group. VAS scores indicated that pain was relieved
27
only in the experimental group. However, pain was unrelated to strength production.
28 29
Conclusion: The intervention used in this study might be useful during physical examination to 1
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reveal the potential grip strength of patients. The intervention may also be an effective warm-up
2
training procedure in preparation for conventional grip-strengthening exercises.
3 4 Key Words: Radius fracture; Hand strength; Rehabilitation; Wrist joint.
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Abbreviations: DRF (distal radial fracture); OT (occupational therapy); VAS (visual analogue
9
scale).
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The decrease in grip strength after distal radial fracture (DRF) makes it difficult for patients to use
2
their hands for many daily activities
3
rehabilitation. However, clinical treatment outcomes of DRF patients have not necessarily been
4
satisfactory
3)–6)
1), 2)
, and recovery from this weakness is a major goal of
.
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Numerous researchers have examined the relationships between treatment outcome in terms of
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grip strength, the initial orthopedic treatment procedure, and radiographic examination findings
8
7)–12)
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restoration of grip strength after DRF. Several authors reported that an early initiation of therapy
3),
13)–17)
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, but few studies have determined an effective occupational therapy (OT) treatment for the
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after injury results in a rapid recovery of grip strength
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to clarify what types of exercise are optimal for the quick recovery of or increase in grip strength
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after DRF.
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. However, further studies are required
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18)
The wrist should be stabilized by wrist extensors at a fixed position during the grasp , at
15
approximately 30° of wrist extension to achieve a powerful grip
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have to exert sufficient force to stabilize the wrist joint in the position . Patients with DRF may
17
not be able to exert enough grip strength that corresponds to wrist extension strength. We
18
previously reported that the strength of wrist extensors highly correlated with grip strength in both
19
the affected and unaffected sides of DRF patients, and the decrease in grip strength on the affected
20
side was greater than the value predicted from a regression equation for the unaffected side. In
21
addition, stabilization of the wrist joint with a splint immediately improved grip strength on the
22
affected side . These results suggest that DRF patients were not able to demonstrate their
23
potential grip strength because of their inability to exert sufficient force to stabilize the wrist.
24
Furthermore, treatment of acute DRF with a cast or surgical instruments commonly restricts wrist
25
motion, and muscle disuse due to constriction may decrease muscle activation. Several studies
26
showed that muscle disuse reduced muscle activation level.
19)–22)
. Therefore, wrist extensors 23)
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24)
25), 26)
27 28
27)
Asano et al. reported that DRF patients produced their maximum grip strength at later trials of
3
ACCEPTED MANUSCRIPT 30 consecutive measurements for 6 min, whereas healthy subjects demonstrated their maximum
2
grip strength in the first trial. These researchers suggested that the results in DRF patients might
3
be related to pain and/or the scar formation in the surrounding tissues of the fracture site. However,
4
we hypothesized that the results might be related to the reduced activation of wrist extensors
5
during the early trials, which might be improved through repetitive wrist extension exercises. This
6
hypothesis is based on our clinical experiences and the facts that grip strength tests involve an
7
isometric contraction of wrist extensors, and muscle activation can be enhanced by voluntary
8
contractions28). If these assumptions are correct, repetitive isometric contractions of these muscles
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could lead to an immediate increase in grip strength in DRF patients. This procedure might be
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useful in the examination of the potential grip strength of patients, and it might also be effective in
11
the treatment for the restoration of weakened grip strength. Therefore, the purpose of this study
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was to clarify the effects of repetitive isometric contraction on grip strength in DRF patients.
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Methods
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Participants
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Consecutive patients who were admitted between June and November 2011 to the Department of
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Rehabilitation Medicine at ○○ Hospital for treatment of DRF were included in the present study.
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Participants attended the experiment after they had begun their passive range-of-motion exercises.
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The following exclusion criteria were used: (1) a history of a disease or other injuries that weaken
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the upper extremities; (2) a complication of complex regional pain syndrome, carpal tunnel
25
syndrome, or tendon rupture after injury; (3) difficulty in understanding instructions because of
26
cognitive disorders such as dementia; (4) inability to move the affected wrist to more than 0° of
27
flexion and/or 30° of extension; and (5) bilateral injury.
28 29
The research ethics committee of the School of Nursing and Rehabilitation Sciences at ○○ 4
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University (approval no. 149) and the bioethics committee of ○○ Hospital approved the present
2
study.
3 Forty-four DRF patients were selected for the study, one of whom met an exclusion criterion and
5
was excluded. Twenty-eight of the remaining 43 patients agreed to participate in the study. Written
6
informed consent was obtained from all of the participants. The mean age of the participants was
7
63 ± 13.0 years (range, 27–81 years). Fractures were reduced at a mean of 5.8 ± 6.8 days (range,
8
0–22 days) after injury, and OT was initiated at a mean of 31.5 ± 12.4 days (13–54 days) after
9
injury. The treatment period mean was 69.6 ± 74.7 days (range, 3–301 days). In the initial
10
orthopedic treatments, 11 patients were treated conservatively with casts, and 17 patients
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underwent surgery for fixation of the fracture. In the patients treated with casts, fractures were
12
reduced at a mean of 0.2 ± 0.4 days (range, 0–1 day) after injury, and OT was started a mean of
13
44.8 ± 4.9 days (36–54 days) after injury. In the patients treated with surgery, fractures were
14
reduced at a mean of 9.5 ± 6.4 days (0–22 days) after injury, and OT was started a mean of 22.7 ±
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6.3 days (13–35 days) after injury.
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The definitions of the radiographic examination results (mean ± SD, range) were as follows: mean
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dorsal angulation (−2.6° ± 14.1°, −43° to 12°), the angle measured on the lateral radiograph
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between a line perpendicular to the long axis of the radius and the articular surface indicated by a
20
line joining the volar and dorsal margins of that surface ; mean radial inclination (21.0° ± 5.0°,
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11–28°), the angle measured on the frontal radiograph between a line perpendicular to the long
22
axis of the radius and the radial articular surface indicated by a line joining its radial and ulnar
23
margins ; and mean radial shortening (0.8 ± 2.9 mm, −5 to 6 mm), measured on the frontal
24
radiograph as the vertical distance between the distal end of the ulna and medial corners of the
25
30) radius .
29)
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Study protocol
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Fig. 1 shows the experimental procedures. Every 2 consecutive patients were randomly allocated 5
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either to the experimental or control group.
2 At first, measurements of grip strength and the visual analogue scale (VAS) of pain were
4
performed for each of the participants (pretest). Just after these measurements, participants in the
5
experimental group underwent repetitive wrist extensions only with their affected side during a
6
6-min intervention period, whereas control group participants were allowed a 6-min rest. Just after
7
the intervention period, the grip strength and pain were measured as described in the pretest.
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The wrist extension strength of both hands was measured in all of the participants 10 min after the
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grip strength measurement. All of the measurements were conducted in each patient before their
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routine exercise.
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Repetitive wrist extension
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Participants held a lightweight rod (approximately 5 g; diameter, 1 cm; length, 20 cm) gently with
16
their affected hand to keep their finger joints flexed during repetitions of wrist extension.
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Participants moved their wrists quickly up to the position of full extension and maintained
18
isometric contractions for 3 s with maximum effort. Subsequently, they rested for 3 s, keeping the
19
wrist relaxed. This combination of contraction and relaxation was repeated 10 times for 1 min,
20
followed by a 1-min rest period. This sequence was repeated 3 times. Therefore, 30 repetitions of
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wrist extensions were performed for 6 min. This protocol was decided with reference to Asano et
22
al. Participants were encouraged by the occupational therapist to give their maximum effort
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during each trial.
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27)
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Grip strength measurement
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Grip strength was measured with a Jamar Digital Hand Dynamometera. The grip handle was
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adjusted to the position of the second narrowest width between the bars. The hand dynamometer
29
was calibrated once before all of the data were collected. 6
ACCEPTED MANUSCRIPT 1 Measurements were performed in a standardized manner. Participants were seated in a chair, with
3
the shoulders neutral, elbows at 90° flexion, and forearms neutral in supination/pronation.
4
Participants held the dynamometer without any assistance or support, and they were instructed to
5
clutch it under maximum effort. Two trials were performed for each measurement, and the higher
6
value was adopted. The measurement order of the affected and unaffected sides was randomized
7
for each subject.
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Pain was measured using VAS just after each grip strength measurement. The VAS for pain
12
consists of a 100-mm-long horizontal line with “no pain” at the left end and “worst pain” at the
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right end. Values (in millimeters) were recorded from the left end of the line. The average of 2
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trials was used as the VAS data that corresponded to each grip strength measurement.
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Measurement of wrist extension strength
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The isometric strength of wrist extensors was measured using a handheld dynamometer
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(µTasMT-1b). The measurement order of the left and right sides was randomized for each
20
participant. Fig. 2 shows that measurements were performed while the participant was in a sitting
21
position with the forearm placed on a table, the elbow flexed at approximately 90°, the arm
22
pronated, and the wrist positioned at 30° of extension. A dynamometer pad was placed on the
23
dorsal surface of the hand with the distal edge of the pad set just proximal to the third
24
metacarpophalangeal joint. The midline of the pad was set along the long axis of the third
25
metacarpal bone. Participants held a lightweight rod (previously described) while the hand was
26
examined, and they were instructed to exert maximal wrist extension for 5 s. Each measurement
27
was performed twice, and the higher value was adopted.
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ACCEPTED MANUSCRIPT Statistical analysis
2
The Mann-Whitney test was used for between-subject comparisons, and Wilcoxon signed rank test
3
was used for within-subject comparisons. Fisher’s exact test was used for categorical variables.
4
Two-way analysis of variance was not performed because the statistical prerequisite of normality
5
of error and/or homogeneity of error variance was not fulfilled with the data obtained. The
6
Spearman rank correlation coefficient was used to clarify the relationship between grip strength
7
and wrist extension strength. The significance level was set at 0.05, and 2-tailed tests were
8
performed. Statistical calculations were performed using the textbook of Sigel et al. 31) (Wilcoxon
9
signed rank test) and IBM SPSS Statistics 21c (other than Wilcoxon signed rank test).
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Table 1 shows the demographic data of the experimental and control groups, each with 14
14
participants. Differences between the 2 groups were not significant (p > 0.05) in any of the
15
parameters (age, sex, affected side, type of initial treatment, time to fracture reduction, time to the
16
start of OT, OT duration, radiographic examination, grip strength, or strength of the wrist
17
extensors), although the p value for radial inclination was almost significant.
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Table 2 shows the grip strength just before and after the intervention period. The grip strength on
20
the affected side increased significantly after the intervention only in the experimental group (n =
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10, T- = 1, p = 0.01). Grip strength on the unaffected side also increased significantly after the
22
intervention period only in the experimental group (n = 10, T- = 8.5, p = 0.05).
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Table 3 shows the VAS scores. No significant difference in the baseline pain score on the affected
25
side was found between the experimental and control groups (na = 13, nb = 13, U = 62.5, p = 0.23).
26
Pain on the affected side decreased after the intervention in the experimental group, whereas no
27
significant difference was observed between pretest and posttest pain in the control group.
28
However, the Spearman rank correlation coefficient between changes in pain and grip strength in
29
the experimental group was 0.29 (p = 0.47), which shows that pain decrease might not be the 8
ACCEPTED MANUSCRIPT 1
cause of the grip strength increase.
2 Table 4 and Fig. 3 show the relationship between grip strength and wrist extension strength.
4
Significant and considerably high correlations were found in both groups in all of the conditions.
5
Fig. 3 illustrates the relationship through scatter plots and estimated fitted lines. The filled and
6
unfilled circles represent the affected side of the experimental and control groups, respectively.
7
The filled and unfilled triangles represent the unaffected side of the experimental and control
8
groups, respectively. A strong linear correlation was observed between wrist extension strength
9
and grip strength even when ensemble data (all conditions and both groups) were used. These
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results indicate that grip strength production in the DRF patients was strongly dependent on wrist
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extensor strength across a wide range.
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Discussion
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Immediate effects of repetitive wrist extension on grip force
18
This study examined the effects of repetitive wrist extension on grip strength in DRF patients. The
19
results indicated that grip strength on the affected side was increased through the intervention in
20
the experimental group, but not in the control group. This result suggests that repetitive wrist
21
extension enhanced muscle activation of wrist extensors during a grasp, whereby patients were
22
able to exert their maximal grip strength. Several studies indicated
23
exert sufficient force to stabilize the wrist joint at approximately 30° of extension to achieve a
24
powerful grip. If patients could not exert the requisite wrist force for a powerful grip, their grip
25
strength would be less than their maximum. Therefore, the performing of repetitive wrist
26
extensions before grip strength assessments could potentially increase maximal grip strength
27
measurements in DRF patients. Furthermore, this procedure might be effective as warm-up
28
training before conventional grip strengthening exercises.
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18),19)–22)
that wrist extensors must
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ACCEPTED MANUSCRIPT Several mechanisms have been proposed for increased muscle force due to repetitive movements.
2
Girard et al. 28) reported that running- or strength-based warm-up exercises increased maximum
3
voluntary knee extension torque and knee extensor muscle activation, which suggests direct
4
effects of voluntary exercises on muscle activation and contraction. Meanwhile, Ranatunga et al.32)
5
examined the influence of temperature on the contraction characteristics of the first dorsal
6
interosseus and showed that the maximal twitch tension decreased approximately 50% when
7
cooled from 35–12℃. De Ruiter et al.33) also showed that force generation by the human adductor
8
pollicis muscle decreased with a decrease in lower-arm temperature (36.8–22.3℃). These results
9
suggest that repetitive muscle contractions may have a direct and/or secondary effect on muscle
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activation and contraction via an increase in muscle temperature.
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Our results also showed that grip strength on the unaffected side increased in the experimental
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group but not in the control group, which suggests that so-called cross-training effects34) may have
14
occurred in the present study. These results and increase in muscle activation described earlier
15
suggest that the upper-level neural control of force generation may have changed because of the
16
repetitive muscle contraction.
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VAS scores in the present study suggest that the pain in the affected wrist was relieved through
19
repetitive wrist extension. Asano et al. suggested that repetitive gripping increased the grip force
20
of DRF patients, probably because of the decrease in pain in the injured area through repetitive
21
wrist extensions. Pain in the injured area in the present study decreased during the intervention
22
period only in the experimental group, as Asano et al. also inferred. However, a relationship
23
between pain and grip strength increase was not demonstrated in the present study. Therefore, we
24
could not conclude that pain reduction increased grip force in patients with DRF. Based on the
25
duration from injury onset and the fact that patients underwent OT, the pain measured in the
26
present study might be caused by immobilization during treatment of the injury rather than by the
27
fracture per se
28
area and decrease pain-inducing substances. Recently, several research studies indicated that
29
therapeutic exercises reduced chronic pain . The results in the present study also suggest
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35), 36)
. The repetitive wrist extension exercise might improve ischemia in the injured
37)
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immediate effects of repetitive muscle contractions with vigorous intensity.
2 3 Strong, wide-range linear relationship between grip and wrist extension strength in DRF
5
patients
6
As mentioned in the Introduction, we previously reported24) that the strength of the wrist extensors
7
highly correlated with grip strength on the affected and normal sides of DRF patients and the grip
8
strength of the affected side decreased more than the value predicted from the wrist extensor
9
strength using a regression equation of the normal side. Furthermore, wrist joint stabilization with
10
a splint immediately improved grip strength on the affected side; however, the improvement was
11
less than the value predicted from the regression line of the normal side. Wrist joint fixation with a
12
splint on the normal side conversely weakened grip strength. These results suggest that the
13
optimal wrist angle for maximum gripping tasks varies according to individual subjects.
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14
The present study also found a strong, wide-range relationship between grip and wrist extension
16
strength in DRF patients (Fig. 3). We did not measure wrist extension strength before the
17
intervention. Therefore, we indicated only the results of the post-intervention measurements. The
18
highly consistent and linear relationship might show that the participants fixated their wrist joints
19
at their own optimal angle in contrast to cases in which a splint was used for fixation. This strong
20
relationship between grip strength and wrist extension strength suggests that an increase in grip
21
strength is strongly constrained by wrist extension strength. Finger flexors could not produce their
22
potential muscle strength more than the magnitude corresponding to the wrist extension force.
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24
Our results also suggest the presence of a relationship that is useful for the prediction of recovery
25
from decreased grip strength. Assuming that the relationship between grip and wrist extension
26
strength is optimal, when a point for a specific patient in Fig. 3 is plotted lower and farther away
27
from the line representing optimal “wrist extension to finger flexion” relationship, the finger
28
flexors of the patient should be weak relative to wrist extensor strength. In contrast, when a point
29
is very close to the line, the finger flexors would match wrist extensors or the wrist extensors 11
ACCEPTED MANUSCRIPT would be weak relative to the finger extensors. In the latter case, enhancing the wrist extensor
2
might immediately improve grip force. However, we could not conclude that this relationship
3
existed in the present study because we did not measure wrist extension strength before the
4
intervention. Further studies are needed to clarify this problem. At any rate, detailed investigations
5
on the relationship between wrist extension and grip strength are important to provide insight for
6
the rehabilitation of patients with DRF and likely other patients with gripping function problems.
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1
7
This study had several limitations. First, we did not measure wrist extension strength before the
9
intervention or the angle of wrist joint chosen by participants. Second, statistical analyses were not
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8
optimal for the experimental design because the statistical prerequisites were not met, and
11
nonparametric 2-group comparisons were performed. A study with a larger sample may solve this
12
problem. Furthermore, the selection of interventional movements, movement intensity, and the
13
number of iterations should be reviewed and optimized.
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14 15 Conclusions
17
This study suggests that repetitive maximal wrist extension is useful in physical examinations to
18
reveal the maximal grip force of patients with DRF, and it is effective as a warm-up training
19
procedure in preparation for conventional grip strength exercises.
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References
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11 Suppliers
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a. Jamar Plus+ Digital Hand Dynamometer, Sammons Preston USA1000 Remington Blvd Suite
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210 Bolingbrook, IL 60440-5117 United States
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b. µTas MT-1, Anima Corporation, Tokyo, Japan
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c. IBM SPSS Statistics 21, IBM Japan, 19-21 Hakozaki, Nihonbashi, Chuo-ku, Tokyo 103¥8510
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Japan
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19 Figure Legends
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Fig 1: The study protocol.
22 23 24
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Fig 2: Measurement of wrist extension strength using a handheld dynamometer.
25
Fig 3: The relationship between grip strength and wrist extension strength in all of the subjects.
26
Grip strength after the intervention period was used as the independent variable.
27
15
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Experimental Group
Control Group
U
p 0.5
5(35.7) 9(64.3) 62±13
4(28.6) 10(71.4) 64±14
85.5
0.57 0.35
9(64.3) 5(35.7)
7(50) 7(50)
6(42.9) 7(50) 1(7.1) 5.0±6.7 31.1±12.3 66.4±86.9
5(35.7) 9(64.3) 0(0) 6.6±6.9 31.9±13.0 72.9±63.3
0.41 0.85 0.41
-1.4±14.0 19.1±5.0 1.0±3.3
103 138 86.5
0.82 0.07 0.6
30.4±16.4 15.0±8.9
29.9±10.2 15.0±8.5
84 91
0.54 0.77
18.1±8.0 11.4±4.3
16.8±4.3 10.7±3.1
90.5 103
0.7 0.8
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80.5 94 80
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-3.8±14.6 22.9±4.4 0.6±2.6
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Sex Male n(%) Female n(%) Age, yr (mean±SD) Affected hand Dominant n(%) Non-dominant n(%) Initial treatment Cast immobilization n(%) Open reduction and internal fixation n(%) External fixation n(%) Fractures were reduced (days after trauma) mean±SD Rehabilitation started (days after trauma) mean±SD Duration of rehabilitation, (day) mean±SD Anatomical results Dorsal angulation, (degree) mean±SD Radial inclination, (degree) mean±SD Radial shortenning, (mm) mean±SD Grip strength Unaffected side, (㎏) mean±SD Affected side, (㎏) mean±SD Force of wrist extensors Unaffected side, (㎏) mean±SD Affected side, (㎏) mean±SD
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ACCEPTED Table 1: Characteristics of subjectsMANUSCRIPT in the experimental and control groups
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Table 2: Changes of grip strength during the intervention period (Kg)
Time of measurement Post
T-
Experimental group
15.0±8.9
16.4±9.9
1
Control group
15.0±8.5
15.3±8.2
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Unaffected side
Time of measurement
p value
Pre
Post
T-
p value
0.01
30.4±16.4
31.0±16.5
8.5
0.05
0.26
29.9±10.2
28.8±8.3
30
0.28
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Pre
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Affected side
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Table 3: Changes of the VAS for pain (mm) Time of measurement Pre Post
T-
p value
0
0.03
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Experimental group Affected side
9.4±21.8
2.3±5.1
Unaffected side
0.0±0.0
0.0±0.0
Affected side
18.2±25.4
13.3±23.0
5
0.13
Unaffected side
0.69±2.21
1.23±3.75
0
0.18
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Control group
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Note. Score of 0 indicates "No pain"and score of 100 indicates "Maximum pain".
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Affected side Time of measurement Pre Post 0.73 **
0.79 **
Control group
0.94 **
0.94 **
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Note. Values are Spearman’s rank correlation coefficient ** p < 0.01
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Unaffected side Time of measurement Pre Post
0.87 **
0.86 **
0.87 **
0.7 **
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Experimental group
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Table 4: The relation between the grip strength and the wrist extension strength (rs )
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Every 2 consecutive patients
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Random allocation
Control group
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Experimental group Unaffected limb
Measurement of grip (2 trials ) and VAS
Measurement of grip (2 trials ) and VAS
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Measurement of grip (2 trials ) and VAS
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Measurement of grip (2 trials ) and VAS
Measurement of grip (2 trials ) and VAS
Unaffected limb
Measurement of grip (2 trials ) and VAS
６ minutes intermission
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Repetition of wrist extension
Affected limb
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Affected limb
Measurement of grip (2 trials ) and VAS
Measurement of grip (2 trials ) and VAS
Intermission for more than 10 minutes
Measurements of wrist extension strength : 2 trials
Fig １.
Measurements of wrist extension strength : 2 trials
Measurements of wrist extension strength : 2 trials
Measurements of wrist extension strength : 2 trials
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Fig 2.
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70
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60
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50
40
Affected side of experimental group Unaffected side of experimental group Affected side of control group Unaffected side of control group
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10
0 0
5
10
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Grip strength (Kg)
80
15
20
25
30
35
40
Strength of dorsal-flexors (Kg) Fig 3.
