3. ikhsu. The-r. & Exp. Psychiar. Vol. 7.1, No. 1, pp. 29-38. Printed m Great Britam.
*105-7916/90$3.w)+0.0(1 Pergamon Press plc.
195%.
MUSCLE STRETCHING AS AN ALTERNATIVE TRAINING PROCEDURE CHARLES Wheaton
College
FRANK
R. CARLSON and University
Health
ELLIE Medical
J. NITZ
Sciences.
University
of Kentucky
T. STURGIS
College
JAMES
Jr
State University
ARTHUR of Allied
of Kentucky
L. COLLINS,
Oklahoma
College
RELAXATION
of South Carolina
L. ROGERS
Wheaton
College
Summary - The purpose of this program of research was to explore the use of muscle stretching procedures in relaxation training with a clinical population. In the first controlled study, stretching exercises for four muscle groups (obicularis occuli. sternocleidomastoidi trapezius. tricepslpectoralis major. and forearm/wrist flexors) were prepared. A group of people using these procedures (SR, N= 8) was compared to a group using the Bernstein and Borkovec (1973) tense-release (TR; N = 8) techniques for those same muscle groups. as well as compared to an appropriate group of controls (WL; N = 8). Assessment of physiological (multi-site EMG) and subjective (emotions, muscle tension, and self-efficacy) responses showed that persons in the SR displayed less sadness. less self-reported muscle tension at four sites. and less EMG activity on the r.masseter than persons in the TR group. In the second study. 15 subjects were administered an expanded version of the SR relaxation procedures. Results showed that all subjects reported significant decreases in self-reported levels of muscle tension: muscle tension responders showed lowered trapezius EMG and respiration rates and cardiovascular responders showed lowered diastolic blood pressure. The results are discussed in terms of the utility of relaxation procedures based primarily on muscle stretching exercises for lowering subjective and objective states of arousal.
training has been For many years, relaxation component in cognitiveused as a principal behavioral interventions for the treatment of anxiety and stress-related disorders (Anderson, 1982; Poppen, 1988). Such training is considered to be one of the standard therapeutic interventions even though careful inspection of the treatment outcome literature reveals inconsistent results for relaxation training, as well as a range of techniques used to induce muscular relaxation (Hillenberg &
Collins, 1982). The effectiveness of relaxation therapy is often assumed because of a reduction of presenting complaints or symptoms, and not from a demonstration that relaxation skills have been learned. This methodological approach to relaxation has lead to numerous procedures being adopted, some of which have little experimental or conceptual support. These issues have been reviewed in detail elsewhere (Borkovec & Sides, 1979, Lehrer, 1982; Poppen, 1988) 29
30
CHARLES
R. CARLSON
and a detailed summary or discussion is beyond the scope of this paper. However, relaxation trainingresearch must focus on objective specification of the skills being taught, a conceptual basis for. using a particular methodology, and some indication that subjects master the techniques. Relaxation procedures, either directly or indirectly, focus on reduction in muscle tonus (Poppen, 1988). However, the most commonly cited procedure, progressive relaxation training (cf. Bernstein & Borkovec, 1973), uses muscle tension-release exercises as the means to reduce muscle activity, and as pointed out by Lehrer (1982), most of the modified versions of Jacobson’s (1938) method of progressive relaxation are less effective. A conceptually sound alternative to muscle tension procedures is muscle stretching (Carlson, VenTrella & Sturgis, 1987). The present paper is a validation study using muscle stretching procedures with a clinical population. Muscle stretching has two primary benefits for use in relaxation procedures. First, more length sensitive receptors in the muscle fibers themselves are activated while stretching muscles rather than tensing them (Anderson, 1983). This should, theoretically at least, provide the individual with even stronger contrast effects between periods of stretching and relaxation and foster learning to discriminate tense muscle groups. Secondly, use of muscle stretching techniques has a long history in the fields of sports medicine and physical therapy as a means for relaxing tense muscles. It has been shown that muscle stretching will produce muscle relaxation as long as the muscle stretching is slow and does not cause microscopic tearing of the connective tissue (Anderson, 1983). Muscle stretching is also reported to reduce excitability of the motoneuron pool which may lead to decreased levels of muscle tone, ischemia, and pain (Nouwen & Bush, 1984; Travell, Rinzler, & Herman, 1942; Scholz & Campbell, 1980; Urbscheit, 1979). Because stretching muscles provides not only facilitative contrast effects, but also assists in
et al.
the relaxation of tense muscles, it seemed appropriate to develop and evaluate a series of relaxation exercises based primarily on muscle stretching techniques.
Study One The purpose of the research was to examine the effects of a set of muscle stretching procedures for use in relaxation with a clinical population. In the first study, stretching exercises for four muscle groups (obicularis occuli. sternocleidomastoid/trapezius, triceps/ pectoralis major, and forearm/wrist flexors) were prepared. Initial work with this procedure (Carlson, VenTrella, & Sturgis, 1987) indicated reductions in physiological and selfreport measures of anxiety could be obtained with this approach. In the present study, a group of persons using these procedures was compared to a group using the Bernstein and Borkovec (1973) techniques for those same muscle groups, as well as to an appropriate group of controls. Assessment of physiological and subjective responses were performed on all subjects prior to, during, and after treatment. Method Subjects. Twenty-four moderately tense people ranging in age from 16-50 years served as subjects. They were recruited through media advertisements soliciting volunteers who were currently “experiencing moderate levels of muscle tension or anxiety”. Individuals were accepted for the study provided they completed the initial baseline monitoring and did not have a medical diagnosis that would account for their excessive muscle activity and restrict their practicing relaxation techniques. During the study, subjects could not be involved in any form of treatment for muscle tension that involved medication. As remuneration for their participation, the experimental subjects received treatment for their muscle
Stretch Relaxation
tension in the Behavioral Psychophysiology Laboratory at Wheaton College. Experimental setting. Experimental procedures were conducted with subjects seated in a recliner located in a light and sound attenuated room. The physiological recording equipment was in an adjoining room. The experimenter could communicate with the subjects via a one-way mirror and an intercom system. Physiological measures. Physiological measures were recorded using a Coulbourn physiograph. Modified frontalis, masseter, trapezius and brachioradialis EMG’s were monitored using silver/silver chloride miniature surface electrodes. The EMG bandpass setting was at 40-250 Hz. Signals were integrated over a 5 Electrodes were attached second period. according to standard laboratory procedures (Fridlund & Cacioppo, 1986). Design. Subjects were assigned randomly to one of three groups: stretch relaxation (SR), tense relaxation (TR). or a wait-list control. Eight subjects were assigned to each treatment condition; there were 7 males and 17 females in the study. Three male experimenters who were graduate-level interns completing practicums in the Behavioral Psychophysiology Laboratory administered the pre-post assessments and the experimental treatments. Procedure: Sessions 1 and 6. During the initial contact, subjects were given a brief overview of the study and asked to complete a consent form. They were then asked to comseveral questionnaires (State-Trait plete Anxiety Scale/STAI. Spielberger, Gorsuch & 1970; Anxiety Lushene, Symptom Checklist/ASL. Suinn, 1973; Emotion Assessment Scale/EAS, Carlson, Collins, Steward, Porzelius, Nitz, & Lind, in press; the Tension MannikiniTM, Webster, Ahles, Thompson & Raczynski, 1984; and Self Efficacy for Relaxation/SER). Following this,
31
the psychophysiological recording leads were attached and the subject reclined quietly on the therapy chair for 10 minutes. After the adaptation period, a 2 min baseline assessment of physiological parameters described earlier was made. After the baseline physiological assessment, a stress profiling protocol consisting of 2 min relaxation, 2 min stressful imagery, 2 min pleasant imagery, 2 min relaxation and a final 2 min baseline (each 2 min assessment was followed by as 2 min rest period) was administered. After the stress profile, subjects were asked to complete the TM. STAI-S, EAS, and SER. This same procedure was followed for session 6. Prior to the conclusion of the baseline evaluation, subjects were provided with rating forms for muscle tension (10 cm visual analog scale anchored at one endpoint with least possible muscle tension and at the other end with most possible muscle tension; one scale for each hour the subject was awake) and instructed to rate themselves daily in order to record their subjective levels of muscle tension. Sessions 2 through 5. For each subject, the session began by completion of the same set of questionnaires administered in the first session (STAI-S, TM, EAS, and SER). .Subjects’ selfmonitoring forms were also collected and reviewed. Subjects continued to self-monitor on a daily basis throughout the course of the experiment. Following completion of the questionnaires, subjects were asked to recline and recording sensors (EMG) were attached. All subjects then received instructions via taperecordings played over the intercom system. The tape recordings were chosen to standardize the administration of the procedure and to control for experimenter effects. Previous evidence (Borkovec et al., 1979) suggested that audiotapes would not be effective in lowering EMG activity. However, the concern of the present study was primarily to determine whether or not self reports of muscle tension would demonstrate the efficacy of a SR procedure.
32
CHARLES
R. CARLSON
Subjects in the experimental conditions spent 1Omin adapting to the equipment and surroundings. Then each group engaged in four cycles of 10sec of activity (stretch or tense) followed by 60 set of quiet relaxation. Each cycle corresponded to one of the four muscle-groups under study. Physiological recording was conducted prior to and throughout the course of the cycles. After the four cycles were completed, subjects rested for two minutes at which time physiological recordings were taken again. Finally, subjects were asked to complete the several questionnaires administered earlier in the session before leaving the experimental setting. For subjects in the muscle tensing (TR) condition, instructions for muscle tension were as follows: (1) squint-close your eyes very tightly, (2) pull your chin downward toward your chest and at the same time try to prevent it from actually touching the chest. That is, I want you to counterpose the muscles in the front part of the neck against those of the back part of the neck, (3) push both elbows down against the couch, and (4) make tight fists. The parallel instructions for the subjects in the muscle stretching (SR) conditions involved: (1) pulling the outside corners of the eyelids simultaneously up with the forefingers and down with the thumbs, (2) letting the head sag to the left and then to the right, (3) interlocking the fingers, rotating the palms outward, raising the arms over the head, and letting the arms fall with the pull of gravity, and (4) at chest height, placing hands together flat, then spreading the paired fingers apart and, keeping palms together, slowly moving hands downward until resistance to further movement was felt. Subjects in the wait-list control condition underwent the same physiological assessment pre and post as subjects in the experimental conditions. There was a six week delay between the pre- and posr-evaluations. After the post-assessment, subjects were offered the opportunity of receiving training in progressive relaxation using either muscle tensing or muscle stretching exercises.
et al
Results Plan of Analysis. The design of the experiment permitted two analytic strategies. One strategy involved exploring the efficacy of SR by comparing it directly to the efficacy of the TR approach across sessions 2-5. The other strategy assessed the capacity to recover from laboratory stressors by comparing the results from the profiling procedure across the three experimental conditions. For both strategies. multivariate analyses (MANOVA) were performed. The mean scores used in these analyses were adjusted with one covariate representing baseline measurement within each session to take into account the Law of Initial Values (Wilder, 1967) and another covariate representing the differential between the beginning and ending of the first session. The second covariate reflects individual differences in reactivity, that is the tendencies to comply to the experimental arrangement for reasons not related to the treatment. Removal of variance due to individual differences in reactivity should increase the statistical power of the study. Follow-up comparisons were performed using Duncan’s Multiple Range Test. EfJicacy of Stretch Relaxation. A Group (SR and TR) X Session (2-5) MANOVA was conducted on the data collected from the treatment conditions. The first MANOVA was conducted on data from the Tension Mannikin; muscle tension data for 19 muscle sites were obtained from 10 cm visual analog scales representing muscle tension. The Tension Mannikin MANOVA indicated that there were four muscle sites for which subjects reported differences across groups in levels of muscle tension. These were the r. trapezius (F(1, 12) ~5.37, p< .03); r. brachioradialis (F( 1, 12) = 4.57, p < .05); 1. tricep (F(1, 12) = 3.50, p < .08); and r. tricep (F(1, 12) = 8.98, p < .Ol). There were no other significant differences across groups or group-by-session interactions for selfassessment of tension at specific muscle sites. These results are presented in Table 1.
Stretch
MANOVA analyses of EMG data revealed that the SR group had significantly lower muscle tension in the r. masseter muscle than did the TR group (F(1,12) = 10.86, p < .006, X’s .97 uv and 1.14 uv, respectively). There were no significant differences on EMG data for frontalis, r.trapezius, and r.brachioradialis muscles. There was no main effect or interaction for the STAI-S. On other measures of emotion (EAS), subjects in the SR group (X= SO) reported less sadness than persons in the TR group (X=.93, F(1,12)=5.69,~
*105-7916/90$3.w)+0.0(1 Pergamon Press plc.
195%.
MUSCLE STRETCHING AS AN ALTERNATIVE TRAINING PROCEDURE CHARLES Wheaton
College
FRANK
R. CARLSON and University
Health
ELLIE Medical
J. NITZ
Sciences.
University
of Kentucky
T. STURGIS
College
JAMES
Jr
State University
ARTHUR of Allied
of Kentucky
L. COLLINS,
Oklahoma
College
RELAXATION
of South Carolina
L. ROGERS
Wheaton
College
Summary - The purpose of this program of research was to explore the use of muscle stretching procedures in relaxation training with a clinical population. In the first controlled study, stretching exercises for four muscle groups (obicularis occuli. sternocleidomastoidi trapezius. tricepslpectoralis major. and forearm/wrist flexors) were prepared. A group of people using these procedures (SR, N= 8) was compared to a group using the Bernstein and Borkovec (1973) tense-release (TR; N = 8) techniques for those same muscle groups. as well as compared to an appropriate group of controls (WL; N = 8). Assessment of physiological (multi-site EMG) and subjective (emotions, muscle tension, and self-efficacy) responses showed that persons in the SR displayed less sadness. less self-reported muscle tension at four sites. and less EMG activity on the r.masseter than persons in the TR group. In the second study. 15 subjects were administered an expanded version of the SR relaxation procedures. Results showed that all subjects reported significant decreases in self-reported levels of muscle tension: muscle tension responders showed lowered trapezius EMG and respiration rates and cardiovascular responders showed lowered diastolic blood pressure. The results are discussed in terms of the utility of relaxation procedures based primarily on muscle stretching exercises for lowering subjective and objective states of arousal.
training has been For many years, relaxation component in cognitiveused as a principal behavioral interventions for the treatment of anxiety and stress-related disorders (Anderson, 1982; Poppen, 1988). Such training is considered to be one of the standard therapeutic interventions even though careful inspection of the treatment outcome literature reveals inconsistent results for relaxation training, as well as a range of techniques used to induce muscular relaxation (Hillenberg &
Collins, 1982). The effectiveness of relaxation therapy is often assumed because of a reduction of presenting complaints or symptoms, and not from a demonstration that relaxation skills have been learned. This methodological approach to relaxation has lead to numerous procedures being adopted, some of which have little experimental or conceptual support. These issues have been reviewed in detail elsewhere (Borkovec & Sides, 1979, Lehrer, 1982; Poppen, 1988) 29
30
CHARLES
R. CARLSON
and a detailed summary or discussion is beyond the scope of this paper. However, relaxation trainingresearch must focus on objective specification of the skills being taught, a conceptual basis for. using a particular methodology, and some indication that subjects master the techniques. Relaxation procedures, either directly or indirectly, focus on reduction in muscle tonus (Poppen, 1988). However, the most commonly cited procedure, progressive relaxation training (cf. Bernstein & Borkovec, 1973), uses muscle tension-release exercises as the means to reduce muscle activity, and as pointed out by Lehrer (1982), most of the modified versions of Jacobson’s (1938) method of progressive relaxation are less effective. A conceptually sound alternative to muscle tension procedures is muscle stretching (Carlson, VenTrella & Sturgis, 1987). The present paper is a validation study using muscle stretching procedures with a clinical population. Muscle stretching has two primary benefits for use in relaxation procedures. First, more length sensitive receptors in the muscle fibers themselves are activated while stretching muscles rather than tensing them (Anderson, 1983). This should, theoretically at least, provide the individual with even stronger contrast effects between periods of stretching and relaxation and foster learning to discriminate tense muscle groups. Secondly, use of muscle stretching techniques has a long history in the fields of sports medicine and physical therapy as a means for relaxing tense muscles. It has been shown that muscle stretching will produce muscle relaxation as long as the muscle stretching is slow and does not cause microscopic tearing of the connective tissue (Anderson, 1983). Muscle stretching is also reported to reduce excitability of the motoneuron pool which may lead to decreased levels of muscle tone, ischemia, and pain (Nouwen & Bush, 1984; Travell, Rinzler, & Herman, 1942; Scholz & Campbell, 1980; Urbscheit, 1979). Because stretching muscles provides not only facilitative contrast effects, but also assists in
et al.
the relaxation of tense muscles, it seemed appropriate to develop and evaluate a series of relaxation exercises based primarily on muscle stretching techniques.
Study One The purpose of the research was to examine the effects of a set of muscle stretching procedures for use in relaxation with a clinical population. In the first study, stretching exercises for four muscle groups (obicularis occuli. sternocleidomastoid/trapezius, triceps/ pectoralis major, and forearm/wrist flexors) were prepared. Initial work with this procedure (Carlson, VenTrella, & Sturgis, 1987) indicated reductions in physiological and selfreport measures of anxiety could be obtained with this approach. In the present study, a group of persons using these procedures was compared to a group using the Bernstein and Borkovec (1973) techniques for those same muscle groups, as well as to an appropriate group of controls. Assessment of physiological and subjective responses were performed on all subjects prior to, during, and after treatment. Method Subjects. Twenty-four moderately tense people ranging in age from 16-50 years served as subjects. They were recruited through media advertisements soliciting volunteers who were currently “experiencing moderate levels of muscle tension or anxiety”. Individuals were accepted for the study provided they completed the initial baseline monitoring and did not have a medical diagnosis that would account for their excessive muscle activity and restrict their practicing relaxation techniques. During the study, subjects could not be involved in any form of treatment for muscle tension that involved medication. As remuneration for their participation, the experimental subjects received treatment for their muscle
Stretch Relaxation
tension in the Behavioral Psychophysiology Laboratory at Wheaton College. Experimental setting. Experimental procedures were conducted with subjects seated in a recliner located in a light and sound attenuated room. The physiological recording equipment was in an adjoining room. The experimenter could communicate with the subjects via a one-way mirror and an intercom system. Physiological measures. Physiological measures were recorded using a Coulbourn physiograph. Modified frontalis, masseter, trapezius and brachioradialis EMG’s were monitored using silver/silver chloride miniature surface electrodes. The EMG bandpass setting was at 40-250 Hz. Signals were integrated over a 5 Electrodes were attached second period. according to standard laboratory procedures (Fridlund & Cacioppo, 1986). Design. Subjects were assigned randomly to one of three groups: stretch relaxation (SR), tense relaxation (TR). or a wait-list control. Eight subjects were assigned to each treatment condition; there were 7 males and 17 females in the study. Three male experimenters who were graduate-level interns completing practicums in the Behavioral Psychophysiology Laboratory administered the pre-post assessments and the experimental treatments. Procedure: Sessions 1 and 6. During the initial contact, subjects were given a brief overview of the study and asked to complete a consent form. They were then asked to comseveral questionnaires (State-Trait plete Anxiety Scale/STAI. Spielberger, Gorsuch & 1970; Anxiety Lushene, Symptom Checklist/ASL. Suinn, 1973; Emotion Assessment Scale/EAS, Carlson, Collins, Steward, Porzelius, Nitz, & Lind, in press; the Tension MannikiniTM, Webster, Ahles, Thompson & Raczynski, 1984; and Self Efficacy for Relaxation/SER). Following this,
31
the psychophysiological recording leads were attached and the subject reclined quietly on the therapy chair for 10 minutes. After the adaptation period, a 2 min baseline assessment of physiological parameters described earlier was made. After the baseline physiological assessment, a stress profiling protocol consisting of 2 min relaxation, 2 min stressful imagery, 2 min pleasant imagery, 2 min relaxation and a final 2 min baseline (each 2 min assessment was followed by as 2 min rest period) was administered. After the stress profile, subjects were asked to complete the TM. STAI-S, EAS, and SER. This same procedure was followed for session 6. Prior to the conclusion of the baseline evaluation, subjects were provided with rating forms for muscle tension (10 cm visual analog scale anchored at one endpoint with least possible muscle tension and at the other end with most possible muscle tension; one scale for each hour the subject was awake) and instructed to rate themselves daily in order to record their subjective levels of muscle tension. Sessions 2 through 5. For each subject, the session began by completion of the same set of questionnaires administered in the first session (STAI-S, TM, EAS, and SER). .Subjects’ selfmonitoring forms were also collected and reviewed. Subjects continued to self-monitor on a daily basis throughout the course of the experiment. Following completion of the questionnaires, subjects were asked to recline and recording sensors (EMG) were attached. All subjects then received instructions via taperecordings played over the intercom system. The tape recordings were chosen to standardize the administration of the procedure and to control for experimenter effects. Previous evidence (Borkovec et al., 1979) suggested that audiotapes would not be effective in lowering EMG activity. However, the concern of the present study was primarily to determine whether or not self reports of muscle tension would demonstrate the efficacy of a SR procedure.
32
CHARLES
R. CARLSON
Subjects in the experimental conditions spent 1Omin adapting to the equipment and surroundings. Then each group engaged in four cycles of 10sec of activity (stretch or tense) followed by 60 set of quiet relaxation. Each cycle corresponded to one of the four muscle-groups under study. Physiological recording was conducted prior to and throughout the course of the cycles. After the four cycles were completed, subjects rested for two minutes at which time physiological recordings were taken again. Finally, subjects were asked to complete the several questionnaires administered earlier in the session before leaving the experimental setting. For subjects in the muscle tensing (TR) condition, instructions for muscle tension were as follows: (1) squint-close your eyes very tightly, (2) pull your chin downward toward your chest and at the same time try to prevent it from actually touching the chest. That is, I want you to counterpose the muscles in the front part of the neck against those of the back part of the neck, (3) push both elbows down against the couch, and (4) make tight fists. The parallel instructions for the subjects in the muscle stretching (SR) conditions involved: (1) pulling the outside corners of the eyelids simultaneously up with the forefingers and down with the thumbs, (2) letting the head sag to the left and then to the right, (3) interlocking the fingers, rotating the palms outward, raising the arms over the head, and letting the arms fall with the pull of gravity, and (4) at chest height, placing hands together flat, then spreading the paired fingers apart and, keeping palms together, slowly moving hands downward until resistance to further movement was felt. Subjects in the wait-list control condition underwent the same physiological assessment pre and post as subjects in the experimental conditions. There was a six week delay between the pre- and posr-evaluations. After the post-assessment, subjects were offered the opportunity of receiving training in progressive relaxation using either muscle tensing or muscle stretching exercises.
et al
Results Plan of Analysis. The design of the experiment permitted two analytic strategies. One strategy involved exploring the efficacy of SR by comparing it directly to the efficacy of the TR approach across sessions 2-5. The other strategy assessed the capacity to recover from laboratory stressors by comparing the results from the profiling procedure across the three experimental conditions. For both strategies. multivariate analyses (MANOVA) were performed. The mean scores used in these analyses were adjusted with one covariate representing baseline measurement within each session to take into account the Law of Initial Values (Wilder, 1967) and another covariate representing the differential between the beginning and ending of the first session. The second covariate reflects individual differences in reactivity, that is the tendencies to comply to the experimental arrangement for reasons not related to the treatment. Removal of variance due to individual differences in reactivity should increase the statistical power of the study. Follow-up comparisons were performed using Duncan’s Multiple Range Test. EfJicacy of Stretch Relaxation. A Group (SR and TR) X Session (2-5) MANOVA was conducted on the data collected from the treatment conditions. The first MANOVA was conducted on data from the Tension Mannikin; muscle tension data for 19 muscle sites were obtained from 10 cm visual analog scales representing muscle tension. The Tension Mannikin MANOVA indicated that there were four muscle sites for which subjects reported differences across groups in levels of muscle tension. These were the r. trapezius (F(1, 12) ~5.37, p< .03); r. brachioradialis (F( 1, 12) = 4.57, p < .05); 1. tricep (F(1, 12) = 3.50, p < .08); and r. tricep (F(1, 12) = 8.98, p < .Ol). There were no other significant differences across groups or group-by-session interactions for selfassessment of tension at specific muscle sites. These results are presented in Table 1.
Stretch
MANOVA analyses of EMG data revealed that the SR group had significantly lower muscle tension in the r. masseter muscle than did the TR group (F(1,12) = 10.86, p < .006, X’s .97 uv and 1.14 uv, respectively). There were no significant differences on EMG data for frontalis, r.trapezius, and r.brachioradialis muscles. There was no main effect or interaction for the STAI-S. On other measures of emotion (EAS), subjects in the SR group (X= SO) reported less sadness than persons in the TR group (X=.93, F(1,12)=5.69,~
