Purpose: Belt electrode skeletal muscle electrical stimulation (B-SES) can stimulate large portions of muscles including deep sites without localisation of the stimulation area. The purpose of this study is to investigate both immediate treatment effects of B-SES and long-term treatment effects of B-SES with passive exercise on range of motion (ROM) and muscle tone of lower extremities in bedridden elderly patients. Methods: Outcome measures before and after B-SES treatment alone (4 Hz, 20 min, both lower extremities) were examined for the immediate effect. Outcome measures were: ROM and Modified Ashworth scale (MAS) of hip flexion and adduction; knee flexion and extension; and knee joint distance at position of flexion abduction in hip (distance of knee). A randomized crossover trial was conducted to examine the long-term effect of adding B-SES to passive exercise on ROM and MAS. Results and Discussion: The immediate effect study had 18 patients. ROM and MAS of 4 joint angles in 2 joints and distance of knee significantly improved after B-SES treatment. The long-term effect study had 11 patients. Friedman test revealed ROM and MAS of 4 joint angles in 2 joints and distance of knee significantly improved during B-SES intervention but not control intervention. B-SES in addition to passive stretch has a more statistically significant effect on contracture and spasticity in large portions of the lower extremities of bedridden elderly patients than passive stretching alone. Conclusions: We consider B-SES a useful tool to improve the ROM in lower extremities of bedridden patients.
Elderly patients who are confined to bed in long-term care (LTC) facilities represent one of the most vulnerable populations. These elderly patients have severe contractures due to the immobilization associated with prolonged bed rest [
Effective interventions for restrictions of ROM induced by contracture and spasticity are currently limited. Full ROM exercises of the upper and lower extremities with stretching are identified as an effective method to improve ROM in bedridden older stroke survivors in LTC facilities [
Belt electrode skeletal muscle electrical stimulation (B-SES) can stimulate large portions of muscles including deep sites without localisation of the stimulation area [
In this study, we investigated both the immediate treatment effects of B-SES and the long-term treatment effects of adding B-SES to passive exercise such as stretching, on muscle tone and contracture in patients who were confined to bed in LTC facilities.
The study protocol was approved by the Research Ethical Committee at the Graduate School of Biomedical Sciences at Nagasaki University (approval number: 16060914-2). Our study was registered in the University Hospital Medical Information Network (UMIN) (Registration number: UMIN000026808). However, the registration date was retrospective to patients’ enrollment.
To examine the immediate treatment effects of B-SES, we performed outcome measures before and after B-SES treatment alone.
Participants were bedridden patients recruited from LTC facilities of Nagasaki Memorial Hospital, Nagasaki, Japan from June 2016 to December 2017. Rehabilitation consisted of passive ROM exercise and sitting or standing that was provided three times per week for all patients before this study started. To be included, the patients’ frailty status was assessed by the Canadian Study of Health and Aging (CSHA)-Clinical Frailty Scale [
Before study entry, demographic characteristics of participants such as age, gender, disease, Clinical Frailty Scale, nutrition management and length of hospitalization were collected and baseline evaluations of the ROM and muscle tone were conducted. All patients provided informed consent prior to study entry. If it was difficult for the patient to understand the explanation and purpose of the study, informed assent was provided.
B-SES treatment was applied to both lower extremities of the participants (
Outcome measures
Before and after B-SES treatment, outcome measures were collected by 2 experienced physiotherapists who were not blinded. The outcome measures for contractures were 4 joint angle measurements in 2 joints that were assessed by a goniometer: hip flexion and adduction; and knee flexion and extension. In addition, the distance between both knee joints at the position of flexion abduction in the hip (distance of knee) was measured using a tape measure. Muscle tone was also assessed, while the therapists measured the range of joint motion, using
the Modified Ashworth scale (MAS) [
The change from pre-B-SES treatment to post-B-SES treatment for each of the outcome measures was compared using the Wilcoxon signed-rank test. Statistical analyses were performed using SPSS for Windows version 22.0. An arbitrary level of 5% statistical significance (two-tailed) was assumed, and the data were reported as the mean ± standard deviation.
To examine the long-term effects of adding B-SES to stretching, a randomized crossover trial was conducted. At the initial assessment, the treating physiotherapist randomly selected patients to be in group A or B by computer-generated randomization lists after baseline measurements were completed. Patients in group A were treated with passive exercise consisting of stretching, sitting, and standing 3 times per week for 12 weeks (control period). Then, after a 2-week washout period, group A patients were treated with B-SES followed by passive exercise 3 times per week for another 12 weeks (intervention period). Patients in group B were treated with B-SES followed by passive exercise 3 times per week for 12 weeks (intervention period). Then, after a 2-week washout period, group B patients were treated with passive exercise 3 times per week for another 12 weeks (control period). To minimize any possible carryover effect between periods in this crossover trial, investigators used a 2-week “washout” phase that was sufficiently long to eliminate the first treatment’s effects.
Participants were bedridden patients recruited from LTC facilities of Nagasaki Memorial Hospital, Nagasaki, Japan from June 2016 to December 2017. Inclusion and exclusion criteria were the same as in Experiment 1. Before study entry, demographic characteristics of participants and baseline evaluations same as Experiment 1 were collected. All patients provided informed consent or assent prior to study entry. We designed this study to detect an effect size of 1.05, according to the results of previous study [
During the intervention periods, B-SES treatments and passive exercise were applied 3 times per week. B-SES treatment was the same method as in Experiment 1. After B-SES treatment, 20 min of passive exercise consisted of full ROM movements in three joints (hip, knee, and ankle) including flexion, extension, adduction, abduction, internal and external rotations, dorsal and plantar flexions, and sitting or standing.
During the control periods, 20 min of passive exercise, as stated above, was applied 3 times per week.
In the control and intervention periods, outcome measures were collected by 2 experienced physiotherapists who were not blinded to intervention allocation at week 0 (baseline), week 4, week 8, and week12. In the intervention period, however, outcome measures were conducted immediately after the first intervention for both groups to examine the immediate effect of B-SES treatment. Outcome measures were conducted in a similar way as Experiment 1.
Variables were compared between the allocated sequence using the independent t-test for continuous variables and Chi-squared or Mann–Whitney U tests for the categorical variables. The mean percentage changes obtained at the end of the B-SES intervention were compared with the results at the end of the control intervention using the paired Student t-test for the ROM and distance of knee data, and the Wilcoxon signed-rank test for MAS. To identify carryover, the period and treatment effects of B-SES intervention, data of ROM and MAS of each joint, and movement at 3 months in Period 1 or 2 were used. The sum of data in each period was compared between groups A and B to analyse carryover effect. Half of each period difference was compared between group A (period 2-period 1) and B (period 1-period 2) to analyse period effect. Half of the difference between period 1 and 2 (period 1-period 2) was compared between groups A and B to analyse treatment effect. The carryover period and treatment effects were tested using the appropriate Student t-test.
The MAS and ROM data of the control period of groups A and B (22 legs) were used to identify the effect of passive exercise only. On the other hand, the MAS and ROM data of the intervention period of groups A and B (22 legs) were used to identify the effect of B-SES + passive exercise only. Friedman’s test was used for this analysis.
Statistical analyses were performed using SPSS for Windows version 22.0. An arbitrary level of 5% statistical significance (two-tailed) was assumed, and the data were reported as the mean ± standard deviation.
We enrolled 18 patients (10 female) for a total of 36 lower extremities in Experiment 1, and
The data showing the immediate effects of B-SES treatment at 2 measurement times (pre- and post-B-SES treatment) are presented in
Characteristics | Mean ± SD/n | |
---|---|---|
Age | 81.7±9.27 | |
Gender (men/women) | 8/10 | |
BMI (kg/m2) | 16.7±1.9 | |
Disease | Cerebral infarction | 12 |
Cerebral hemorrhage | 2 | |
Subarachnoid hemorrhage | 1 | |
Hypoxic ischemic encephalopathy | 1 | |
Pneumonia | 2 | |
Nutrition management | Enteral nutrition (oral/tube) | 2/14 |
Parenteral nutrition | 2 | |
Length of hospitalization (days) | 1202.6 ± 977.0 |
Abbreviations: SD: standard deviation; BMI: body mass index.
Hip flexion (˚) | Hip abduction (˚) | Knee flexion (°) | Knee extension (°) | Knee distance (cm) | ||||||
---|---|---|---|---|---|---|---|---|---|---|
ROM | Before | After | Before | After | Before | After | Before | After | Before | After |
Mean | 97.6 | 101.8 | 15.8 | 19.7 | 142.9 | 144.9 | −40.1 | −37.1 | 32.3 | 35.4 |
SD | 14.1 | 16.6 | 10.9 | 10.8 | 16.4 | 16.5 | 29.6 | 28.0 | 13.3 | 13.6 |
95%CI | 95 - 105 | 100 - 110 | 15 - 20 | 20 - 25 | 145 - 150 | 145 - 155 | −50 - −20 | −45 - −20 | 24 - 42 | 27.5 - 47 |
p | p = 0.0002 | p < 0.0001 | p = 0.0006 | p = 0.004 | p < 0.0001 | |||||
MAS | Before | After | Before | After | Before | After | Before | After | Before | After |
Mean | 2.0 | 1.6 | 3.1 | 2.7 | 1.5 | 1.2 | 1.4 | 0.9 | 3.2 | 2.8 |
SD | 1.7 | 1.6 | 1.5 | 1.5 | 1.7 | 1.5 | 1.5 | 1.4 | 1.4 | 1.4 |
95%CI | 1 - 4 | 0 - 3 | 3 - 4 | 3 - 4 | 0 - 3 | 0 - 1 | 0 - 2 | 0 - 1 | 2 - 4 | 1 - 4 |
p | p = 0.0004 | p = 0.0028 | p = 0.008 | p = 0.0006 | p = 0.0078 |
Abbreviations: ROM: range of motion; MAS: modified Ashworth scale; SD: standard deviation; 95%CI: 95% confidence Interval.
and distance of knee, respectively. The mean ± SD decrease in the MAS score by the treatment was −0.39 ± 0.11 points, −0.39 ± 0.13 points, −0.3 ± 0.15 points, −0.44 ± 0.14 points, and −0.44 ± 0.12 points for hip flexion, abduction, knee flexion, knee extension, and distance of knee, respectively. There was a statistically significant difference between pre- and post-B-SES treatment.
The flow chart in
Total Mean ± SD/n | Group A Mean ± SD/n | Group B Mean ± SD/n | ||
---|---|---|---|---|
Age | 83.1 ± 6.0 | 84.4 ± 4.3 | 82 ± 7.3 | |
Gender (men/women) | 11 | 2/3 | 2/4 | |
BMI (kg/m2) | 16.3 ± 2.0 | 16.6 ± 1.8 | 16.0 ± 2.3 | |
Disease | Cerebral infarction | 9 | 4 | 5 |
Cerebral hemorrhage | 1 | 1 | 0 | |
Subarachnoid hemorrhage | 1 | 0 | 1 | |
Nutrition management | Enteral nutrition (oral/tube) | 11 | 0/5 | 2/4 |
Parenteral nutrition | 0 | 0 | 0 | |
Length of hospitalization (days) | 1496.7 ± 1042.8 | 1567 ± 756.8 | 1438.2 ± 1306.8 |
Abbreviations: SD: standard deviation; BMI: body mass index.
Carryover effect was not observed for any outcome measures. Treatment effects were present for all outcome measures. Period effect was present only in MAS and ROM of knee flexion (
During the B-SES intervention period (irrespective of the phase), the mean (± SD) change of the ROM from baseline to 3 months was 5.0˚ ± 7.6˚, 3.7˚ ± 7.6˚, 3.0˚ ± 5.5˚, 2.6˚ ± 7.2˚, and 5.4 ± 3.8 cm for hip flexion, hip abduction, knee flexion, knee extension, and distance of knee, respectively. The Friedman test showed statistical differences and the post-hoc test results are presented in
During the control period, the mean (± SD) change of the ROM from baseline to 3 months was −0.4˚ ± 9.2˚, −0.2˚ ± 4.4˚, 1.5˚ ± 14.7˚, −3.3˚ ± 9.3˚, and −0.7 ± 5.0 cm for hip flexion, hip abduction, knee flexion, knee extension, and distance of knee, respectively. The Friedman test showed statistical differences and the post-hoc test results are presented in
Carryover effect/ p value | Treatment effect/ p value | Period effect/ p value | |
---|---|---|---|
ROM | |||
Hip flexion | 14.50/0.303 | 5.333/0.005* | 0.333/0.847 |
Hip abduction | 0.450/0.949 | 4.808/0.0002* | 1.891/0.090 |
Knee flexion | 3.083/0.810 | 2.958/0.005* | 2.458/0.017* |
Knee extension | 20.63/0.341 | 5.650/0.001* | 0.650/0.669 |
Knee distance | 5.233/0.717 | 5.550/0.0005* | 1.050/0.340 |
MAS | |||
Hip flexion | 0.116/0.914 | 0.358/0.007* | 0.441/0.110 |
Hip abduction | 1.000/0.421 | 0.816/0.007* | 0.016/0.952 |
Knee flexion | 1.350/0.052 | 0.541/0.017* | 0.458/0.039* |
Knee extension | 0.033/0.967 | 0.566/0.020* | 0.233/0.314 |
Knee distance | 0.800/0.644 | 1.300/0.006* | 0.700/0.088 |
*p < 0.05, Abbreviations: ROM: range of motion; MAS: modified Ashworth scale.
BL | Week 4 | Week 8 | Week 12 | Friedmann test (p value) | ||
---|---|---|---|---|---|---|
ROM | ||||||
Hip Flexion (°) | Mean | 97.7 | 101.6 | 103.2# | 102.7# | 0.001 |
SD | 3.3 | 3.6 | 3.6 | 3.6 | ||
95%CI | 90 - 110 | 95 - 110 | 95 - 115 | 95 - 115 | ||
Hip abduction (°) | Mean | 19.3 | 21.4 | 21.6 | 23.0# | 0.015 |
SD | 2.1 | 2.0 | 2.0 | 1.8 | ||
95%CI | 15 - 25 | 15 - 30 | 15 - 25 | 20 - 25 | ||
Knee flexion (°) | Mean | 142.7 | 143.6 | 144.6 | 145.7 | 0.014 |
SD | 3.4 | 3.1 | 3.1 | 3.1 | ||
95%CI | 140 - 150 | 140 - 150 | 140 - 155 | 145 - 155 | ||
Knee extension (°) | Mean | −31.8 | −31.8 | −30.4 | −29.2 | 0.045 |
SD | 5.1 | 5.2 | 5.4 | 5.3 | ||
95%CI | −45 - −15 | −45 - −10 | −40 - −10 | −40 - −10 | ||
Knee distance (cm) | Mean | 36.5 | 40.9 | 42.0# | 42.5# | 0.001 |
SD | 3.6 | 3.5 | 3.6 | 3.4 | ||
95%CI | 26 - 48 | 29 - 54 | 30 - 53 | 33 - 55 | ||
MAS | ||||||
Hip Flexion | Mean | 1.7 | 1.3 | 1.0 | 0.9 | 0.012 |
SD | 0.4 | 0.3 | 0.3 | 0.3 | ||
95%CI | 0 - 4 | 0 - 3 | 0 - 2 | 0 - 1 | ||
Hip abduction | Mean | 2.7 | 2.3 | 2.1 | 1.8# | 0.002 |
SD | 0.3 | 0.3 | 0.3 | 0.3 | ||
95%CI | 1 - 4 | 1 - 4 | 1 - 4 | 1 - 4 | ||
Knee flexion | Mean | 1.2 | 0.8 | 0.3 | 0.2 | 0.000 |
SD | 0.3 | 0.3 | 0.3 | 0.2 | ||
95%CI | 0 - 3 | 0 - 1 | 0 - 0 | 0 - 0 | ||
Knee extension | Mean | 1.0 | 0.5 | 0.5 | 0.3 | 0.001 |
SD | 0.3 | 0.2 | 0.2 | 0.2 | ||
95%CI | 0 - 2 | 0 - 0 | 0 - 0 | 0 - 0 | ||
Knee distance | Mean | 2.9 | 2.7 | 2.5 | 2.0 | 0.011 |
SD | 0.4 | 0.5 | 0.5 | 0.5 | ||
95%CI | 1 - 4 | 1 - 4 | 1 - 4 | 1 - 4 |
#, significant difference compared to BL. Abbreviations: BL: baseline; SD: standard deviation; 95%CI: 95% confidence Interval; ROM: range of motion; MAS: modified Ashworth scale.
BL | Week 4 | Week 8 | Week 12 | Friedmann test (p value) | ||
---|---|---|---|---|---|---|
ROM | ||||||
Hip Flexion (°) | Mean | 97.7 | 97.5 | 97.9 | 97.4 | 0.880 |
SD | 3.3 | 3.6 | 3.6 | 3.5 | ||
95%CI | 90 - 105 | 90 - 110 | 90 - 105 | 90 - 110 | ||
Hip abduction (°) | Mean | 18.6 | 17.9 | 18.9 | 18.4 | 0.595 |
SD | 2.1 | 2.0 | 2.0 | 1.8 | ||
95%CI | 15 - 25 | 15 - 20 | 15 - 25 | 15 - 25 | ||
Knee flexion (°) | Mean | 141.0 | 143.0 | 143.2 | 142.5 | 0.834 |
SD | 3.4 | 3.1 | 3.1 | 3.1 | ||
95%CI | 145 - 150 | 145 - 150 | 140 - 155 | 140 - 155 | ||
Knee extension (°) | Mean | −31.5 | −30.9 | −35.5 | −34.8 | 0.020 |
SD | 5.1 | 5.2 | 5.4 | 5.3 | ||
95%CI | −50 - −15 | −40 - −15 | −50 - −15 | −50 - −10 | ||
Knee distance (cm ) | Mean | 37.7 | 38.5 | 37.3 | 37.0 | 0.397 |
SD | 3.6 | 3.5 | 3.6 | 3.4 | ||
95%CI | 23 - 54 | 28 - 52 | 27 - 51 | 26 - 50 | ||
MAS | ||||||
Hip Flexion | Mean | 1.3 | 1.1 | 1.3 | 1.2 | 0.760 |
SD | 0.4 | 0.3 | 0.3 | 0.3 | ||
95%CI | 0 - 3 | 0 - 2 | 0 - 2 | 0 - 2 | ||
Hip abduction | Mean | 2.7 | 2.3 | 2.1 | 1.8 | 0.076 |
SD | 0.3 | 0.3 | 0.3 | 0.3 | ||
95%CI | 2 - 4 | 1 - 4 | 1 - 3 | 0 - 3 | ||
Knee flexion | Mean | 0.6 | 0.6 | 0.7 | 0.7 | 0.739 |
SD | 0.3 | 0.3 | 0.3 | 0.2 | ||
95%CI | 0 - 0 | 0 - 1 | 0 - 0 | 0 - 1 | ||
Knee extension | Mean | 0.8 | 0.6 | 1.0 | 0.9 | 0.207 |
SD | 0.3 | 0.2 | 0.3 | 0.2 | ||
95%CI | 0 - 1 | 0 - 1 | 0 - 2 | 0 - 1 | ||
Knee Distance | Mean | 2.6 | 3.0 | 2.5 | 3.4 | 0.128 |
SD | 0.5 | 0.5 | 0.5 | 0.5 | ||
95%CI | 1 - 4 | 2 - 4 | 1 - 4 | 2 - 4 |
Abbreviations: BL: baseline; SD: standard deviation; 95%CI: 95% confidence Interval; ROM: range of motion; MAS: modified Ashworth scale.
difference in only knee extension ROM values during the control period. However, the post-hoc test showed no significant differences. The mean ± SD change of the MAS from baseline to 3 months was −0.09 ± 0.87 points, −0.55 ± 0.96 points, −0.09 ± 0.43 points, −0.09 ± 0.68 points, and −0.73 ± 1.62 points for hip flexion, hip abduction, knee flexion, knee extension, and distance of knee, respectively. The Friedman test showed statistical differences and the post-hoc test results are presented in
The results of this study identified a statistically significant effect of B-SES when added to passive stretch on spasticity and contracture over passive exercise alone. In addition, this effect was observed in large portions of the lower extremities. The mechanisms by which electrical stimulation might bring about these improvements were not examined in this study; however, it has been suggested that electrical stimulation may reduce the resistance to passive range of motion [
Our results show that an immediate effect of B-SES is a significant decrease in muscle tone. It is hypothesised that plastic effects within specific spinal cord circuitries (i.e. short-latency autogenic inhibition [Ib inhibition], recurrent inhibition from Renshaw cells, disynaptic reciprocal Ia inhibition, presynaptic inhibition of Ia terminals, and post-activation depression) may be associated with the reduced spasticity induced by treatments with neuromuscular electrical stimulation (NMES) [
Our results of the long-term effect of B-SES in addition to passive exercise show a statistically significant decrease in muscle tone and increase in ROM compared to passive exercise alone. These results suggest that passive exercise only can maintain ROM but B-SES in addition to passive exercise can improve ROM. Although the usage of electrical stimulation with a frequency between 30 and 50 Hz combined with other treatments was associated with an increase of ROM in stroke patients [
The effect of B-SES in addition to passive exercise was statistically significant but marginal. Tseng et al. reported a 7˚ - 12˚ improvement in ROM of the lower extremities of bedridden stroke patients using ROM exercise (4 weeks, twice-per-day, 6 days-per week) [
There are several limitations of this study. First, therapists and patients were not blinded. Second, the sample size was small. Third, the study design is a crossover design, thus, we need a randomized controlled trial to identify the effect of B-SES more clearly. In addition, the mechanism of improving ROM was not investigated, thus, we need electrophysiological and/ or histological observation to define this mechanism. Furthermore, the electrical stimulation delivered to the lower extremities was 4 Hz, and it is possible that other frequencies of B-SES could produce different effects on MAS or ROM.
In conclusion, B-SES in addition to passive stretch has a more statistically significant effect on spasticity and contracture in large portions of the lower extremities of bedridden elderly patients than passive stretching alone. We consider B-SES a useful tool to improve the ROM of bedridden patients in LTC.
We wish to thank all of the study patients who completed the survey. Atsushi NAWATA (ALCARE Co., Ltd.) gave intellectual support for the B-SES procedure and maintenance.
The authors declare no conflicts of interest regarding the publication of this paper.
Kataoka, H., Nakashima, S., Aoki, H., Goto, K., Yamashita, J., Honda, Y., Kondo, Y., Hirase, T., Sakamoto, J. and Okita, M. (2019) Electrical Stimulation in Addition to Passive Exercise Has a Small Effect on Spasticity and Range of Motion in Bedridden Elderly Patients: A Pilot Randomized Crossover Study. Health, 11, 1072-1086. https://doi.org/10.4236/health.2019.118084