Accepted Manuscript Title: The effect of progressive task-oriented training on a supplementary tilt table on lower extremity muscle strength and gait recovery in patients with hemiplegic stroke Author: Chang-Yong Kim Jung-Sun Lee Hyeong-Dong Kim June-Sun Kim PII: DOI: Reference:
S0966-6362(14)00757-7 http://dx.doi.org/doi:10.1016/j.gaitpost.2014.11.004 GAIPOS 4352
To appear in:
Gait & Posture
Received date: Revised date: Accepted date:
15-5-2014 11-10-2014 13-11-2014
Please cite this article as: Kim C-Y, Lee J-S, Kim H-D, Kim J-S, The effect of progressive task-oriented training on a supplementary tilt table on lower extremity muscle strength and gait recovery in patients with hemiplegic stroke, Gait and Posture (2014), http://dx.doi.org/10.1016/j.gaitpost.2014.11.004 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.
1. Title:
ip t
The effect of progressive task-oriented training on a supplementary tilt table
2. Authors full contact details
an
(1) Chang-Yong Kim
us
in patients with hemiplegic stroke
cr
on lower extremity muscle strength and gait recovery
- Affiliation: Department of Health Science, The Graduate School, Korea University
M
- Address: Department of Health Science, The Graduate School, Korea University, Jeongneung 3-Dong,
- Telephone: +82-10-9807-0113 - Fax: +82-2-940-2830
Ac ce
(2) Jung-Sun Lee
pt
- E-mail: [email protected]
ed
Seongbuk-Gu, Seoul, 136-703, Republic of Korea
- Affiliation: Department of Epidemiology and Health Informatics, The Graduate School of Public Health, Korea University
- Address: Department of Epidemiology and Health Informatics, The Graduate School of Public Health, Korea University, Anam-Dong, Seongbuk-Gu, Seoul, 136-703, Republic of Korea
- Telephone: +82-10-3115-6119 - Fax: +82-2-2286-1175 - E-mail: [email protected]
(3) Hyeong-Dong Kim 1
Page 1 of 19
- Affiliation: Department of Physical Therapy, College of Health Science, Korea University - Address: Jeongneung 3-Dong, Sungbuk-Gu, Seoul 136-703, Republic of Korea - Telephone: +82-2-940-2835 - Fax: +82-2-940-2830
ip t
- E-mail: [email protected]
(4) June-Sun Kim
cr
- Affiliation: Department of Physical Therapy, College of Health Science, Korea University
us
- Address: Jeongneung 3-Dong, Sungbuk-Gu, Seoul 136-703, Republic of Korea - Telephone: +82-2-940-2835
- E-mail: [email protected]
M
3. Corresponding author: Hyeong-Dong Kim
an
- Fax: +82-2-940-2834
- Affiliation: Department of Physical Therapy, College of Health Science, Korea University
- Telephone: +82-2-940-2835
pt
- Fax: +82-2-940-2830
ed
- Address: Jeongneung 3-Dong, Sungbuk-Gu, Seoul 136-703, Republic of Korea
Ac ce
- E-mail: [email protected]
4. Word / Figure / Table counts - Word count for the abstract : 260
- Word count for the main text (excluding reference list and legends) : 3,269 - Number of tables : 3
- Number of figures : 2 - Number of reference list : 29 - Number of pages (excluding abstract and reference list) : 7
5. Keywords: 2
Page 2 of 19
Gait, Muscle strength, Task-oriented training, Tilt table,
ip t
Stroke
Abstract
cr
The purpose of this study was to determine the influence of progressive task-oriented training on a
us
supplementary tilt table on the lower extremity (LE) muscle strength and spatiotemporal parameters of gait in subjects with hemiplegic stroke. Thirty subjects between three and nine months post stroke were included in this
an
study. Thirty subjects were randomly allocated to a control group (CG, n1=10), experimental group I (EG1, n2=10), and experimental group II (EG2, n3=10). All of the subjects received routine therapy for half an hour, five times a week for three weeks and additionally received training on the following three different tilt table applications for
M
20 minutes a day: (1) both knee belts of the tilt table were fastened (CG), (2) only the affected side knee belt of the tilt table was fastened and one-leg standing training was performed using the less-affected LE (EG1), and (3)
ed
only the affected side knee belt of the tilt table was fastened and progressive task-oriented training was performed using the less-affected LE (EG2). The effect of tilt table applications was assessed using a hand-held dynamometer
pt
for LE muscle strength and GAITRite for spatiotemporal gait data. Our results showed that there was a significantly greater increase in the strength of all LE muscle groups, gait velocity, cadence, and stride length, a
Ac ce
decrease in the double limb support period, and an improvement in gait asymmetry in subjects who underwent progressive task-oriented training on a supplementary tilt table compared to those in the other groups. These findings suggest that progressive task-oriented training on a supplementary tilt table can improve the LE muscle strength and spatiotemporal parameters of gait at an early stage of rehabilitation of subjects with hemiplegic stroke.
3
Page 3 of 19
The effect of progressive task-oriented training on a supplementary tilt table on lower extremity muscle strength and gait recovery in patients with hemiplegic stroke
ip t
Abstract
The purpose of this study was to determine the influence of progressive task-oriented training on a
cr
supplementary tilt table on the lower extremity (LE) muscle strength and spatiotemporal parameters of gait in subjects with hemiplegic stroke. Thirty subjects between three and nine months post stroke were included in this
us
study. Thirty subjects were randomly allocated to a control group (CG, n1=10), experimental group I (EG1, n2=10), and experimental group II (EG2, n3=10). All of the subjects received routine therapy for half an hour, five times a week for three weeks and additionally received training on the following three different tilt table
an
applications for 20 minutes a day: (1) both knee belts of the tilt table were fastened (CG), (2) only the affected side knee belt of the tilt table was fastened and one-leg standing training was performed using the less-affected LE (EG1), and (3) only the affected side knee belt of the tilt table was fastened and progressive task-oriented
M
training was performed using the less-affected LE (EG2). The effect of tilt table applications was assessed using a hand-held dynamometer for LE muscle strength and GAITRite for spatiotemporal gait data. Our results showed that there was a significantly greater increase in the strength of all LE muscle groups, gait velocity,
ed
cadence, and stride length, a decrease in the double limb support period, and an improvement in gait asymmetry in subjects who underwent progressive task-oriented training on a supplementary tilt table compared to those in
pt
the other groups. These findings suggest that progressive task-oriented training on a supplementary tilt table can improve the LE muscle strength and spatiotemporal parameters of gait at an early stage of rehabilitation of
Ac ce
subjects with hemiplegic stroke.
Keywords: Gait; Muscle strength; Task-oriented training; Tilt table; Stroke
1. Introduction
Several studies have confirmed that lack of movement leads quickly to profound negative biomechanical and physiological changes in all systems and organs of the body [1,2]. As these patients suffering from diseases such as post-stroke and traumatic brain injury are bedridden, the instability of circulatory system occurs at an early stage of rehabilitation and leads to the appearance of atrophy and weakness in the affected leg [3]. So these musculoskeletal instabilities also lead to delayed functional training of these patients [1], it is important for these patients to be progressively mobilized and to undergo weight-supported load training at an early state of rehabilitation [4]. 4
Page 4 of 19
As stroke patients are bedridden immediately after brain damage, the lack of adequate rehabilitation may lead to the appearance of irreversible anatomical and functional changes, as well as progressive weakness [3]. In the clinical setting, most therapists aim to increase the mobility of lower extremities (LE) and weight-supported load training in patients through manual therapy (neuro-developmental techniques) or using supplementary cycling ergometers and a tilt table [1]. The tilt table is a method that has been used for over 60 years by physiologists and physicians for many
ip t
purposes. This includes the study of the human body's heart rate and blood pressure adaptations to changes in position, for modeling responses to hemorrhage, as a technique for evaluating of orthostatic hypotension, as a method to study hemodynamic and neuroendocrine responses in congestive heart failure, autonomic dysfunction
cr
and hypertension, as well as a tool for drug research [5,6,7]. It also has become a useful device in the mobilization of spinal cord and traumatic brain injured patients, as well as in patients suffering from stroke
us
under the supervision of a physical therapist [8]. In particular, the position of a stroke patient can be continuously changed from horizontal to vertical by using a tilt table during the early stage of rehabilitation. The use of a tilt table enables patients to adapt to the state of walking for training just prior to it, as well as to prevent
an
muscle atrophy and weakness [1].
However, a more effective and standardized method for applying a tilt table, which is used as a supplementary treatment in the early rehabilitation of stroke patients, has not been presented. A tilt table consists
M
of safety thoracic, pelvic, and knee belts. These belts are connected to the side of a tilt table and are used to prevent forward tipping and to fix the patients’ body while they are standing or leaning against it. The use of a tilt table is appropriately supervised by physical therapists who gradually increase the patient's standing angle
ed
[3,9]. In general, during the application of a tilt table in a clinic setting, the patients are strapped by knee belts of both the affected and less-affected LEs, which leads to delay in the proprioceptive input and in achievement of sufficient locomotion ability to perform various activities of daily living [10]. Based on the above background
pt
on research, the aim of our experiment was as follows: to evaluate the impact of progressive task-oriented training on a supplementary tilt table by applying a knee belt in a different manner on LE function such as
Ac ce
muscle strength and abilities associated with gait such as gait velocity and symmetry at an early stage of rehabilitation of stroke patients.
2. Methods
2.1 Subjects
Thirty subjects (15 women, 15 men) with first-ever stroke from the stroke rehabilitation institute participated in this study and gave their informed consent. Sample size estimate was based on data collected from previous studies [3,11]. A priori power analysis determined that a sample size of 10 subjects with first-ever stroke in each group was required to obtain a statistical power of 0.80 using the General power analysis program (GPower 3.1) [12]. This was based on one-way ANOVA measurements of the comparison among the three groups, with a predetermined reliability coefficient of 0.9 [13]. Subjects were selected if they had stable 5
Page 5 of 19
hemodynamics in the absence of significant LE contractures (with an Ashworth index < 2 in all of the LE muscles: average 0.8 ± 0.5 [mean ± SD]), orthopedic impairment, significant cardiovascular impairment, or a score above 24 in the Mini-Mental State Examination. Subjects were excluded from the study if they presented with cardiac arrhythmia, thrombophlebitis, significant perceptual, cognitive, or communication impairments, diabetes, and contra-indication for tilt table (cancer, pacemaker, unstable epilepsy) [1,3].
ip t
2.2 Equipment and data collection
cr
Functional changes in LE were evaluated using muscle strength and gait performance measurements, which were performed before and after the three-week intervention period. Two physical therapists who were
us
blinded to group allocation performed the evaluations. Prior to performing muscle strength measurements, these blinded evaluators underwent a 6-hour training session. Rater competence was assessed by the primary investigator who had seven-year experience in using these measures. These evaluators were trained to conduct
an
the gait performance measurements in accordance with the standardized procedures described below. Subjects were advised not to indicate their treatment assignment to the evaluator.
LE muscle strength was evaluated using a hand-held dynamometer (PowerTrack II; JTech Medical, USA).
M
All tests done were ‘make’ tests in which the dynamometer was held stationary by the examiner while the subjects exerted a maximum force against it. The muscle groups measured included both hip flexors, hip extensors, knee flexors, knee extensors, ankle dorsiflexors, and ankle plantarflexors. The strength of the hip
ed
extensors, knee flexors, and ankle plantarflexors was assessed in the prone position. The strength of the hip flexors and knee extensors was assessed in the sitting position. The strength of the ankle dorsiflexors was
pt
assessed in the supine position [14]. The intra-rater reliability for all LE muscle groups in our sample was determined to be good with intra-class correlation coefficients ranging from 0.72 to 0.89. Gait performance was measured using the GAITRite system (AP1105, GAITRite EWPV CIR, USA), an
Ac ce
instrumented walkway. The GAITRite system provided temporal (time) and spatial (distance) gait parameters via an electronic walkway connected to the serial port of a personal computer. The standard GAITRite walkway contains six sensor pads encapsulated in a roll-up carpet with an active area of 3.7 m in length and 0.6 m in width. As the subject walked through the walkway, the sensors captured each footfall as a function of time and transferred the gathered information to a personal computer to process the raw data into footfall patterns. The computer computed the temporal and spatial gait parameters. The validity and reliability of the GAITRite system has been well established [15,16]. The test-retest reliability of velocity, cadence, and stride length was excellent (intraclass correlation coefficients between 0.90 and 0.95) in a subset of stroke survivors in our laboratory. Subjects were asked to walk at a comfortable speed without an assistive device through a 10-m hallway three times. Data were recorded at 120 Hz and processed with GAITRite software (version 4.0). The GAITRite walkway was placed in the middle of the 10-m hallway to eliminate the effect of acceleration or deceleration. Gait parameters of interest were velocity, cadence, stride length of the affected side, gait symmetry, 6
Page 6 of 19
and double support percentage. Gait velocity was defined as "the subject’s rate of travel by identifying the time needed to cover a designated distance". Cadence was defined as "the number of steps in a standard time frame". The double support period was defined as "the ratio of both feet placed on the ground during the gait cycle". The gait symmetry ratio was defined as the "paretic gait cycle ratio (paretic swing time/paretic stance time) divided by the non-paretic gait cycle ratio (non-paretic swing time/non-paretic stance time)". To estimate gait performances, these parameters were calculated by using a formula, which was established previously by
ip t
Patterson et al [17].
cr
2.3 Test procedure
us
Test procedures are summarized in Figure 1. Group allocation of the subjects was determined by using a randomization procedure, in which each subject drew a ball from a box containing three balls with markings 0 (control group; CG), 1 (experimental group I; EG1), or 2 (experimental group II; EG2), without looking at the
an
ball. Consequently, they were randomly assigned to one of the three groups, CG, EG1, and EG2, based on their characteristics to ensure that there were no significant differences among the groups at baseline (Table 1). Over a 3-week period, all of the subjects received functional training according to the daily routine schedule in the
M
clinical setting, which consisted of strengthening and stretching exercises of the limbs, postural control training in sitting and standing positions, therapist-guided techniques for facilitating the normal movement pattern, and simple forward stepping. They received the above routine therapy for half an hour, five times a week. The
ed
subjects in each group additionally received training on the supplementary tilt table (Midland Manufacturing Co., Inc., Columbia, SC, USA) for 20 minutes a day while they were positioned such that they felt comfortable
pt
at a tilt angle. Each group received training on the following three different tilt table applications: CG - Subjects were strapped by safety thoracic, pelvic, and both knee belts; EG1 - While subjects were strapped by safety
Ac ce
thoracic, pelvic, and only affected side knee belts, they performed one-leg standing training with the lessaffected LE for 10s, and then there was a 5s rest period; EG2 - While subjects were strapped by safety thoracic, pelvic, and only affected side knee belts, they performed progressive task-oriented training such as kick ball and target-matched exercises with the less-affected LE (Fig. 2). The tilt table was tilted in a range from 0° to 90° in the horizontal position. During the 20-minute phase of the intervention, all of the subjects were placed in the supine position on the tilt table, and were allowed to gradually increase their maximum tilt angle and to reduce their tilt angle during a session if they felt light headed. If they experienced dizziness or nausea during the experimental procedures, we immediately stopped the experiment, and then the subjects rested in the supine position. Furthermore, we used a therapeutic foam roller (length 60 cm, width 15 cm) for preventing knee hyper-extension in the subjects.
(Insert Table 1 here)
7
Page 7 of 19
(Insert Figure 1 here)
(Insert Figure 2 here)
2.4 Data processing and statistical analysis
ip t
Statistical analysis of the data was performed by using the SPSS 12.0 software (SPSS Inc., Chicago, IL, USA). The values in each group were expressed as means and standard deviations. Since the samples included
cr
in this study showed normal distribution curves in the Kolmogorov-Smirnov test, parametric methods were used. The chi-square test (gender, side of hemiplegia, and type of stroke) and one-way analysis of variance (ANOVA)
us
(age, weight, height, duration, and Mini-Mental State Examination) were used to compare demographic characteristics of the subjects in the 3 groups. Comparison of the LE muscle strength and gait performance among the groups at pre-test and post-test was performed using repeated-measures one-way ANOVA, followed
an
by the Bonferroni’s post hoc test. Consequently, this test examined between-group differences (intervention time × group ANOVA), and the post hoc test was performed to identify the locus of interactions. The paired ttest was performed to compare the same parameters before and after intervention within each group. To
M
determine the statistical significance of the data collected from the subjects, the significance level was set at p
S0966-6362(14)00757-7 http://dx.doi.org/doi:10.1016/j.gaitpost.2014.11.004 GAIPOS 4352
To appear in:
Gait & Posture
Received date: Revised date: Accepted date:
15-5-2014 11-10-2014 13-11-2014
Please cite this article as: Kim C-Y, Lee J-S, Kim H-D, Kim J-S, The effect of progressive task-oriented training on a supplementary tilt table on lower extremity muscle strength and gait recovery in patients with hemiplegic stroke, Gait and Posture (2014), http://dx.doi.org/10.1016/j.gaitpost.2014.11.004 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.
1. Title:
ip t
The effect of progressive task-oriented training on a supplementary tilt table
2. Authors full contact details
an
(1) Chang-Yong Kim
us
in patients with hemiplegic stroke
cr
on lower extremity muscle strength and gait recovery
- Affiliation: Department of Health Science, The Graduate School, Korea University
M
- Address: Department of Health Science, The Graduate School, Korea University, Jeongneung 3-Dong,
- Telephone: +82-10-9807-0113 - Fax: +82-2-940-2830
Ac ce
(2) Jung-Sun Lee
pt
- E-mail: [email protected]
ed
Seongbuk-Gu, Seoul, 136-703, Republic of Korea
- Affiliation: Department of Epidemiology and Health Informatics, The Graduate School of Public Health, Korea University
- Address: Department of Epidemiology and Health Informatics, The Graduate School of Public Health, Korea University, Anam-Dong, Seongbuk-Gu, Seoul, 136-703, Republic of Korea
- Telephone: +82-10-3115-6119 - Fax: +82-2-2286-1175 - E-mail: [email protected]
(3) Hyeong-Dong Kim 1
Page 1 of 19
- Affiliation: Department of Physical Therapy, College of Health Science, Korea University - Address: Jeongneung 3-Dong, Sungbuk-Gu, Seoul 136-703, Republic of Korea - Telephone: +82-2-940-2835 - Fax: +82-2-940-2830
ip t
- E-mail: [email protected]
(4) June-Sun Kim
cr
- Affiliation: Department of Physical Therapy, College of Health Science, Korea University
us
- Address: Jeongneung 3-Dong, Sungbuk-Gu, Seoul 136-703, Republic of Korea - Telephone: +82-2-940-2835
- E-mail: [email protected]
M
3. Corresponding author: Hyeong-Dong Kim
an
- Fax: +82-2-940-2834
- Affiliation: Department of Physical Therapy, College of Health Science, Korea University
- Telephone: +82-2-940-2835
pt
- Fax: +82-2-940-2830
ed
- Address: Jeongneung 3-Dong, Sungbuk-Gu, Seoul 136-703, Republic of Korea
Ac ce
- E-mail: [email protected]
4. Word / Figure / Table counts - Word count for the abstract : 260
- Word count for the main text (excluding reference list and legends) : 3,269 - Number of tables : 3
- Number of figures : 2 - Number of reference list : 29 - Number of pages (excluding abstract and reference list) : 7
5. Keywords: 2
Page 2 of 19
Gait, Muscle strength, Task-oriented training, Tilt table,
ip t
Stroke
Abstract
cr
The purpose of this study was to determine the influence of progressive task-oriented training on a
us
supplementary tilt table on the lower extremity (LE) muscle strength and spatiotemporal parameters of gait in subjects with hemiplegic stroke. Thirty subjects between three and nine months post stroke were included in this
an
study. Thirty subjects were randomly allocated to a control group (CG, n1=10), experimental group I (EG1, n2=10), and experimental group II (EG2, n3=10). All of the subjects received routine therapy for half an hour, five times a week for three weeks and additionally received training on the following three different tilt table applications for
M
20 minutes a day: (1) both knee belts of the tilt table were fastened (CG), (2) only the affected side knee belt of the tilt table was fastened and one-leg standing training was performed using the less-affected LE (EG1), and (3)
ed
only the affected side knee belt of the tilt table was fastened and progressive task-oriented training was performed using the less-affected LE (EG2). The effect of tilt table applications was assessed using a hand-held dynamometer
pt
for LE muscle strength and GAITRite for spatiotemporal gait data. Our results showed that there was a significantly greater increase in the strength of all LE muscle groups, gait velocity, cadence, and stride length, a
Ac ce
decrease in the double limb support period, and an improvement in gait asymmetry in subjects who underwent progressive task-oriented training on a supplementary tilt table compared to those in the other groups. These findings suggest that progressive task-oriented training on a supplementary tilt table can improve the LE muscle strength and spatiotemporal parameters of gait at an early stage of rehabilitation of subjects with hemiplegic stroke.
3
Page 3 of 19
The effect of progressive task-oriented training on a supplementary tilt table on lower extremity muscle strength and gait recovery in patients with hemiplegic stroke
ip t
Abstract
The purpose of this study was to determine the influence of progressive task-oriented training on a
cr
supplementary tilt table on the lower extremity (LE) muscle strength and spatiotemporal parameters of gait in subjects with hemiplegic stroke. Thirty subjects between three and nine months post stroke were included in this
us
study. Thirty subjects were randomly allocated to a control group (CG, n1=10), experimental group I (EG1, n2=10), and experimental group II (EG2, n3=10). All of the subjects received routine therapy for half an hour, five times a week for three weeks and additionally received training on the following three different tilt table
an
applications for 20 minutes a day: (1) both knee belts of the tilt table were fastened (CG), (2) only the affected side knee belt of the tilt table was fastened and one-leg standing training was performed using the less-affected LE (EG1), and (3) only the affected side knee belt of the tilt table was fastened and progressive task-oriented
M
training was performed using the less-affected LE (EG2). The effect of tilt table applications was assessed using a hand-held dynamometer for LE muscle strength and GAITRite for spatiotemporal gait data. Our results showed that there was a significantly greater increase in the strength of all LE muscle groups, gait velocity,
ed
cadence, and stride length, a decrease in the double limb support period, and an improvement in gait asymmetry in subjects who underwent progressive task-oriented training on a supplementary tilt table compared to those in
pt
the other groups. These findings suggest that progressive task-oriented training on a supplementary tilt table can improve the LE muscle strength and spatiotemporal parameters of gait at an early stage of rehabilitation of
Ac ce
subjects with hemiplegic stroke.
Keywords: Gait; Muscle strength; Task-oriented training; Tilt table; Stroke
1. Introduction
Several studies have confirmed that lack of movement leads quickly to profound negative biomechanical and physiological changes in all systems and organs of the body [1,2]. As these patients suffering from diseases such as post-stroke and traumatic brain injury are bedridden, the instability of circulatory system occurs at an early stage of rehabilitation and leads to the appearance of atrophy and weakness in the affected leg [3]. So these musculoskeletal instabilities also lead to delayed functional training of these patients [1], it is important for these patients to be progressively mobilized and to undergo weight-supported load training at an early state of rehabilitation [4]. 4
Page 4 of 19
As stroke patients are bedridden immediately after brain damage, the lack of adequate rehabilitation may lead to the appearance of irreversible anatomical and functional changes, as well as progressive weakness [3]. In the clinical setting, most therapists aim to increase the mobility of lower extremities (LE) and weight-supported load training in patients through manual therapy (neuro-developmental techniques) or using supplementary cycling ergometers and a tilt table [1]. The tilt table is a method that has been used for over 60 years by physiologists and physicians for many
ip t
purposes. This includes the study of the human body's heart rate and blood pressure adaptations to changes in position, for modeling responses to hemorrhage, as a technique for evaluating of orthostatic hypotension, as a method to study hemodynamic and neuroendocrine responses in congestive heart failure, autonomic dysfunction
cr
and hypertension, as well as a tool for drug research [5,6,7]. It also has become a useful device in the mobilization of spinal cord and traumatic brain injured patients, as well as in patients suffering from stroke
us
under the supervision of a physical therapist [8]. In particular, the position of a stroke patient can be continuously changed from horizontal to vertical by using a tilt table during the early stage of rehabilitation. The use of a tilt table enables patients to adapt to the state of walking for training just prior to it, as well as to prevent
an
muscle atrophy and weakness [1].
However, a more effective and standardized method for applying a tilt table, which is used as a supplementary treatment in the early rehabilitation of stroke patients, has not been presented. A tilt table consists
M
of safety thoracic, pelvic, and knee belts. These belts are connected to the side of a tilt table and are used to prevent forward tipping and to fix the patients’ body while they are standing or leaning against it. The use of a tilt table is appropriately supervised by physical therapists who gradually increase the patient's standing angle
ed
[3,9]. In general, during the application of a tilt table in a clinic setting, the patients are strapped by knee belts of both the affected and less-affected LEs, which leads to delay in the proprioceptive input and in achievement of sufficient locomotion ability to perform various activities of daily living [10]. Based on the above background
pt
on research, the aim of our experiment was as follows: to evaluate the impact of progressive task-oriented training on a supplementary tilt table by applying a knee belt in a different manner on LE function such as
Ac ce
muscle strength and abilities associated with gait such as gait velocity and symmetry at an early stage of rehabilitation of stroke patients.
2. Methods
2.1 Subjects
Thirty subjects (15 women, 15 men) with first-ever stroke from the stroke rehabilitation institute participated in this study and gave their informed consent. Sample size estimate was based on data collected from previous studies [3,11]. A priori power analysis determined that a sample size of 10 subjects with first-ever stroke in each group was required to obtain a statistical power of 0.80 using the General power analysis program (GPower 3.1) [12]. This was based on one-way ANOVA measurements of the comparison among the three groups, with a predetermined reliability coefficient of 0.9 [13]. Subjects were selected if they had stable 5
Page 5 of 19
hemodynamics in the absence of significant LE contractures (with an Ashworth index < 2 in all of the LE muscles: average 0.8 ± 0.5 [mean ± SD]), orthopedic impairment, significant cardiovascular impairment, or a score above 24 in the Mini-Mental State Examination. Subjects were excluded from the study if they presented with cardiac arrhythmia, thrombophlebitis, significant perceptual, cognitive, or communication impairments, diabetes, and contra-indication for tilt table (cancer, pacemaker, unstable epilepsy) [1,3].
ip t
2.2 Equipment and data collection
cr
Functional changes in LE were evaluated using muscle strength and gait performance measurements, which were performed before and after the three-week intervention period. Two physical therapists who were
us
blinded to group allocation performed the evaluations. Prior to performing muscle strength measurements, these blinded evaluators underwent a 6-hour training session. Rater competence was assessed by the primary investigator who had seven-year experience in using these measures. These evaluators were trained to conduct
an
the gait performance measurements in accordance with the standardized procedures described below. Subjects were advised not to indicate their treatment assignment to the evaluator.
LE muscle strength was evaluated using a hand-held dynamometer (PowerTrack II; JTech Medical, USA).
M
All tests done were ‘make’ tests in which the dynamometer was held stationary by the examiner while the subjects exerted a maximum force against it. The muscle groups measured included both hip flexors, hip extensors, knee flexors, knee extensors, ankle dorsiflexors, and ankle plantarflexors. The strength of the hip
ed
extensors, knee flexors, and ankle plantarflexors was assessed in the prone position. The strength of the hip flexors and knee extensors was assessed in the sitting position. The strength of the ankle dorsiflexors was
pt
assessed in the supine position [14]. The intra-rater reliability for all LE muscle groups in our sample was determined to be good with intra-class correlation coefficients ranging from 0.72 to 0.89. Gait performance was measured using the GAITRite system (AP1105, GAITRite EWPV CIR, USA), an
Ac ce
instrumented walkway. The GAITRite system provided temporal (time) and spatial (distance) gait parameters via an electronic walkway connected to the serial port of a personal computer. The standard GAITRite walkway contains six sensor pads encapsulated in a roll-up carpet with an active area of 3.7 m in length and 0.6 m in width. As the subject walked through the walkway, the sensors captured each footfall as a function of time and transferred the gathered information to a personal computer to process the raw data into footfall patterns. The computer computed the temporal and spatial gait parameters. The validity and reliability of the GAITRite system has been well established [15,16]. The test-retest reliability of velocity, cadence, and stride length was excellent (intraclass correlation coefficients between 0.90 and 0.95) in a subset of stroke survivors in our laboratory. Subjects were asked to walk at a comfortable speed without an assistive device through a 10-m hallway three times. Data were recorded at 120 Hz and processed with GAITRite software (version 4.0). The GAITRite walkway was placed in the middle of the 10-m hallway to eliminate the effect of acceleration or deceleration. Gait parameters of interest were velocity, cadence, stride length of the affected side, gait symmetry, 6
Page 6 of 19
and double support percentage. Gait velocity was defined as "the subject’s rate of travel by identifying the time needed to cover a designated distance". Cadence was defined as "the number of steps in a standard time frame". The double support period was defined as "the ratio of both feet placed on the ground during the gait cycle". The gait symmetry ratio was defined as the "paretic gait cycle ratio (paretic swing time/paretic stance time) divided by the non-paretic gait cycle ratio (non-paretic swing time/non-paretic stance time)". To estimate gait performances, these parameters were calculated by using a formula, which was established previously by
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Patterson et al [17].
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2.3 Test procedure
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Test procedures are summarized in Figure 1. Group allocation of the subjects was determined by using a randomization procedure, in which each subject drew a ball from a box containing three balls with markings 0 (control group; CG), 1 (experimental group I; EG1), or 2 (experimental group II; EG2), without looking at the
an
ball. Consequently, they were randomly assigned to one of the three groups, CG, EG1, and EG2, based on their characteristics to ensure that there were no significant differences among the groups at baseline (Table 1). Over a 3-week period, all of the subjects received functional training according to the daily routine schedule in the
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clinical setting, which consisted of strengthening and stretching exercises of the limbs, postural control training in sitting and standing positions, therapist-guided techniques for facilitating the normal movement pattern, and simple forward stepping. They received the above routine therapy for half an hour, five times a week. The
ed
subjects in each group additionally received training on the supplementary tilt table (Midland Manufacturing Co., Inc., Columbia, SC, USA) for 20 minutes a day while they were positioned such that they felt comfortable
pt
at a tilt angle. Each group received training on the following three different tilt table applications: CG - Subjects were strapped by safety thoracic, pelvic, and both knee belts; EG1 - While subjects were strapped by safety
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thoracic, pelvic, and only affected side knee belts, they performed one-leg standing training with the lessaffected LE for 10s, and then there was a 5s rest period; EG2 - While subjects were strapped by safety thoracic, pelvic, and only affected side knee belts, they performed progressive task-oriented training such as kick ball and target-matched exercises with the less-affected LE (Fig. 2). The tilt table was tilted in a range from 0° to 90° in the horizontal position. During the 20-minute phase of the intervention, all of the subjects were placed in the supine position on the tilt table, and were allowed to gradually increase their maximum tilt angle and to reduce their tilt angle during a session if they felt light headed. If they experienced dizziness or nausea during the experimental procedures, we immediately stopped the experiment, and then the subjects rested in the supine position. Furthermore, we used a therapeutic foam roller (length 60 cm, width 15 cm) for preventing knee hyper-extension in the subjects.
(Insert Table 1 here)
7
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(Insert Figure 1 here)
(Insert Figure 2 here)
2.4 Data processing and statistical analysis
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Statistical analysis of the data was performed by using the SPSS 12.0 software (SPSS Inc., Chicago, IL, USA). The values in each group were expressed as means and standard deviations. Since the samples included
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in this study showed normal distribution curves in the Kolmogorov-Smirnov test, parametric methods were used. The chi-square test (gender, side of hemiplegia, and type of stroke) and one-way analysis of variance (ANOVA)
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(age, weight, height, duration, and Mini-Mental State Examination) were used to compare demographic characteristics of the subjects in the 3 groups. Comparison of the LE muscle strength and gait performance among the groups at pre-test and post-test was performed using repeated-measures one-way ANOVA, followed
an
by the Bonferroni’s post hoc test. Consequently, this test examined between-group differences (intervention time × group ANOVA), and the post hoc test was performed to identify the locus of interactions. The paired ttest was performed to compare the same parameters before and after intervention within each group. To
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determine the statistical significance of the data collected from the subjects, the significance level was set at p
