Search

Neuromuscular electrical stimulation (NMES) is widely used for improving muscle strength, preventing muscle atrophy, and decreasing pain. Recently, NMES has become a substitute for exercise therapy for metabolism improvement and functional capacity improvement. However, NMES has several disadvantages. First, slow-twitch muscle contractions are insufficient because the recruitment pattern of NMES does not obey Henneman's size principle. Second, when using surface electrodes, it is difficult to contract deep skeletal muscles at the application site. Third, electrical stimulation causes discomfort. Therefore, we devised a simultaneous combination of NMES and voluntary muscle contractions to overcome the weak points of NMES. A hybrid training system (HTS) that resists the motion of a volitionally contracting agonist muscle with force generated by its electrically stimulated antagonist was developed as a technique to combine the application of NMES and volitional contractions. This motion sensor makes it possible to simultaneously combine voluntary movements with NMES. Our HTS synchronizes with voluntary movements, enhancing safety and reducing discomfort. This HTS enhances the exercise effect of even simple exercise. So far, our HTS has been reported to be effective for muscle strength enhancement, prevention of muscle atrophy, improvement of physical function, pain relief, enhancement of physical fitness, and improvement of metabolic function. HTS are expected to be useful methods in environments where sufficient exercise load is not available or for individuals with low exercise tolerance.

The purpose of this study is to clarify whether a hip range of motion (ROM) measurement is useful in screening for early hip osteoarthritis with acetabular dysplasia (AD). Subjects were 58 healthy Japanese women volunteers (21.1 ± 0.7 (20 - 22)). We evaluated a total of 116 hip joints in these 58 cases. Sharp angle and centeredge angle were 44.1° ± 3.1° (37.0° - 51.5°) and 30.7°± 6.2° (19.5° - 47.0°), respectively. AD was present in 47.4%, but there were no severe cases. First, we compared the ROM of the hip joints with AD (AD group) and without AD (control group) according to the Mann-Whitney U test. Extension angles and external rotation angles in the AD group were significantly smaller than in the control group (18.9°± 6.1° VS. 22.1°± 4.2°, p= 0.01636, 26.3°± 8.9° VS. 34.1°± 8.8°, p= 0.001362, respectively). Next, we evaluated the following factors associated with AD by logistic regression analysis after adjustment for age: flexion, extension and internal and external rotation angles of the hip joint. As a result, internal rotation and external rotation were extracted as related factors. The area under the ROC curve was determined to have a moderate accuracy (0.72996). Cut off values of internal rotation and external rotation angles were 50 degrees and 35 degrees, respectively. Our findings suggest that ROM measurement of the internal and external rotation angles would be useful as a screening for AD in healthy young Japanese women without symptoms.

Increased liver stiffness and insulin resistance are important therapeutic targets in patients with nonalcoholic fatty liver disease (NAFLD). A hybrid training system (HTS) has been developed which combines application of electrical stimulation and volitional contractions. We compared the effect of walking exercise (5.6 km/h) both with and without simultaneous HTS on liver stiffness and insulin resistance. In a single-blind, controlled trial, 32 subjects with NAFLD were randomized to 12 weeks of triweekly 30 minute walking exercise with either HTS (HTS group) or without HTS (control group). Transient elastography for the assessment of liver stiffness, body weight, visceral fat, the homeostasis model assessment of insulin resistance, fasting blood glucose, serum aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyl transpeptidase were evaluated. Data were evaluated using the linear model after adjusting the baseline value. In the subjects with BMI of 27 kg/m 2 or more, the decrement of transient elastography in the HTS group was significantly larger than in the control group (mean ± standard error: Δ2.13 ± 0.64 kPa vs. Δ-0.67 ± 0.42 kPa, p=0.0009). There were no significant differences between groups in other endpoints. These results showed that simultaneously combining electrical stimulation with walking exercise could potentially improve liver stiffness in people who have NAFLD. In fact, because the exercise effect was increased by HTS without increasing the walking speed, this HTS could be especially useful for obese or overweight subjects, in whom NAFLD and joint problems often coexist. However, its effects on insulin resistance and body composition were not clear.

Objective: Trunk muscle mass can be evaluated by skeletal muscle index (SMI), which is a prognostic factor in patients with hepatocellular carcinoma (HCC); however, this requires the use of computed tomography, and a simpler assessment for trunk muscle mass is urgently needed. We aimed to examine whether an association between SMI and lower extremity compartments including muscle and subcutaneous fat thickness of lower limbs (SFT-LL) could be identified by means of ultrasonography in patients with HCC., Methods: We retrospectively enrolled male patients with HCC (n=30). Trunk muscle mass was evaluated by SMI using computed tomography. Ultrasonography was used for assessment of muscle and SFT-LL. Factors associated with SMI were evaluated by decision-tree analysis., Results: There was no significant correlation between SMI and muscle thickness of lower limbs. However, a significant correlation was seen between SMI and left SFT-LL (r=0.406, P=0.026). In decision-tree analysis for SMI, left SFT-LL was selected as the initial split variable with an optimal cut-off value of 5 mm. In patients with left SFT-LL ≥ 5 mm, SMI was 39.4±3.4 cm 2 /m 2 , whereas SMI was 31.6±6.3 cm 2 /m 2 in patients with left SFT-LL <5 mm., Conclusion: Left SFT-LL evaluated by ultrasonography was associated with SMI. Thus, ultrasonography may be a useful tool to evaluate trunk muscle mass. Moreover, left SFT-LL may be a useful indicator of sarcopenia in patients with HCC.

Background: Patients with hip fracture are limited as to physical activity. It is difficult to evaluate the physical function of the legs at admission; however, it is easy to measure grip strength, which has been reported to be correlated with systemic muscular strength and physical function. The objective of this study was to investigate the utility of grip strength in predicting functional outcome after hip fracture., Methods: Fifty-seven patients who underwent surgery for hip fracture were evaluated for height, weight, Body Mass Index (BMI), grip strength, bone density (femoral neck), hemoglobin, Hemoglobin A1c (HbA1c), Hasegawa's Dementia Scale-Revised (HDS-R), and albumin at admission and Functional Independence Measure (FIM) at discharge. Spearman's rank correlation coefficient was used to evaluate the relation between grip strength and the above variables. Furthermore, factors of walking acquisition were analyzed by logistic regression analysis and decision-tree analysis., Results: Correlation analysis showed that grip strength was positively correlated with bone density at admission and FIM at discharge and negatively correlated with age. In the logistic regression analysis, the independent factor associated with walking acquisition was grip strength (OR 1.26; 95%CI 1.018-1.566; p=0.0339). In the decisiontree analysis, grip strength was the initial divergence variable for walking acquisition (the percentage with walking acquisition was 80.0% of the patients with grip strength ≧13.2 kg VS. 18.7% of the patients with grip strength < 13.2 kg)., Conclusions: Grip strength at admission was definitive in predicting the functional outcome of patients with hip fracture who underwent surgery.

Neuromuscular electrical stimulation (NMES) is used to increase not only muscle strength but also whole-body metabolism. A hybrid training system (HTS) in which NMES is synchronized to voluntary exercise by an articular motion sensor may increase exercise load during aerobic walking exercise. We assessed the metabolic cost during walking exercise (5 minutes at 4 km/h and 5.6 km/h) on a treadmill simultaneously combined with HTS (HTSW) or without HTS (CON). We evaluated oxygen uptake ( VO · 2 ) and heart rate (HR) during HTSW or CON on different days in fifteen subjects. The values ofVO · 2 during HTSW at 4 km/h and 5.6 km/h were signifi cantly greater than those during CON (16.6 ± 1.85 ml/min/kg vs 15.3 ± 1.48 ml/min/kg; p < 0.05, 21.0 ± 2.17 ml/min/kg vs 19.4 ± 2.13 ml/min/kg; p < 0.01, respectively). The values of HR during HTSW at 4 km/h, 5.6 km/h were significantly greater than those during CON (106.7 ± 8.1 bpm vs 101.7 ± 10.3 bpm; p < 0.05, 126.5 ± 11.1 bpm vs 121.5 ± 12.5 bpm; p < 0.05, respectively). HTS added significantly to the exercise load by 8.3 ± 12.0% or 9.1 ± 9.9% during aerobic walking exercise at 4 km/h or 5.6 km/h, respectively. HTS might be useful for health promotion by increasing metabolic cost during aerobic walking exercise without increasing the perceived difficulty.

Objective: Muscle atrophy is associated with autologous stem cell transplantation (ASCT)-related outcomes in patients with malignant lymphoma (ML). However, the impact of ASCT on muscle mass remains unclear in patients with ML. The aims of this study were to investigate changes in muscle mass and risk profiles for muscle atrophy after ASCT., Method: We enrolled 40 patients with refractory ML (age 58 [20-74] years, female/male 16/24, body mass index (BMI) 21.1 kg/m 2 [17.1-29.6]). Psoas muscle mass was assessed using the psoas muscle index (PMI) before and after ASCT., Statistical Analysis Used: Independent factors associated with a severe decrease rate of change in PMI were evaluated by decision-tree analysis, respectively., Results: PMI was significantly decreased after ASCT (4.61 vs. 4.55 cm 2 /m 2 ; P=0.0425). According to the decision-tree analysis, the regimen was selected as the initial split. The rates of change in PMI were -5.57% and -3.97% for patients administered MCEC and LEED, respectively. In patients who were administered LEED, the second branching factor was BMI. In patients with BMI < 20.3 kg/m 2 , the rate of change in PMI was -7.16%. On the other hand, the rate of change in PMI was 4.05% for patients with BMI ≥ 20.3 kg/m 2 ., Conclusion: We demonstrated that muscle mass decreased after ASCT in patients with ML. Patients who received MCEC and patients with low BMI were at risk for a decrease in muscle mass., Competing Interests: There is no conflict of interest to disclose., (2021, JAPANESE PHYSICAL THERAPY ASSOCIATION.)

Background: Osteoarthritis of the knee (KOA) is the most common cause of disability in both the United States and in Japan. The Hybrid training system (HTS) has been developed as a resistance exercise method combining electrical stimulation with voluntary exercise. The purpose of the present study is to compare the effects of a conventional rehabilitation program with or without HTS on knee muscle strength and physical function after Total knee arthroplasty (TKA)., Methods: We conducted a 12-week randomized controlled trial, using standard rehabilitation (the control group, n = 27) or standard rehabilitation plus HTS (the HTS group, n= 26), in 53 female patients after TKA. The HTS group underwent HTS three times per week for twelve weeks after TKA. Muscle strength, thigh circumference, physical functional testing, QOL and knee pain were assessed before surgery, 6 and 12 weeks after TKA., Results: There was a significant decrease in quadriceps strength and thigh circumference on the operative side in the control group, but not in the HTS group at 6 weeks. Hamstring strength on the operative side in the HTS group significantly increased and thigh circumference was bigger than in the control group at 12 weeks. Physical function improved at 6 weeks in the HTS group, but not in the control group. Knee pain significantly improved in both groups at 6 weeks., Conclusions: HTS was effective in preventing quadriceps weakness and in improving physical function and QOL after TKA.

The SEM Glove developed by Bioservo Technologies AB is a new device that increases grip and pinch force. The purpose of this study was to evaluate the effectiveness of the device on the grip and pinch strength of patients with functional disorders of the fingers., Materials and Method: 30 hospitalized patients with upper limb functional disorder were enrolled. The assistance of the device for the grip and pinch strength of each subject were assessed by the difference between the measured values with and without the SEM Glove. The 95% confidence interval of the difference was calculated across the subjects, and statistical significance was defined as when the lower limit was a positive value (corresponding with a paired t-test at a significance level of 0.05). The odds ratio was calculated in the study of subject adaptation, with statistical significance set using Fisher's exact test at a significance level of 0.05., Results: Grip strength significantly decreased (worn-not worn difference (kg): mean = -3.7, CI95 (-5.4, -2.1)). Pinch strength (thumb - middle finger) significantly increased (worn-not worn difference (N): mean = -4.1, CI95 (1.6, 6.6)). Analysis of factors related to improvement in hand function when wearing the SEM Glove extracted manual muscle tests (MMTs) of the upper extremity 4 or higher. The odds ratio was 6.11., Conclusions: Use of the SEM Glove improved the pinch strength of patients with functional disorders of the hands.

Background: Knee osteoarthritis (OA) is a leading cause of disability that is associated with quadriceps weakness. However, strengthening in people with or with risk factors for knee OA can be poorly tolerated., Objective: To assess the efficacy of a 12-week low-load exercise program, using a hybrid training system (HTS) that uses the combination of neuromuscular electrical stimulation and volitional contractions, for improving thigh muscle strength, knee pain relief, and physical performance in women with or with risk factors for knee OA., Design: Randomized, single-blinded, controlled trial., Setting: Exercise training laboratory., Participants: Forty-two women 44-85 years old with risk factors for knee OA., Interventions: Participants randomized to 12 weeks of biweekly low-load resistance training with the HTS or on an isokinetic dynamometer (control)., Outcomes: Maximum isokinetic knee extensor torque. Secondary measures included maximum isokinetic knee flexor torque, knee pain (Knee Injury and Osteoarthritis Outcome Score), and timed 20-m walk and chair stand tests., Results: The HTS and control treatments resulted in muscle strengthening, decreased knee pain, and improved physical performance. HTS group quadriceps and hamstring strength increased by 0.06 ± 0.04 Nm/kg (P > .05) and 0.05 ± 0.02 Nm/kg (P = .02), respectively. Control group quadriceps and hamstring strength increased by 0.03 ± 0.04 Nm/kg (P > .05) and 0.06 ± 0.02 Nm/kg (P = .009), respectively. Knee pain decreased by 11.9 ± 11.5 points (P < .001) for the HTS group and 14.1 ± 15.4 points (P = .001) for the control group. The 20-m walk time decreased by 1.60 ± 2.04 seconds (P = .005) and 0.95 ± 1.2 seconds (P = .004), and chair stand time decreased by 4.8 ± 10.0 seconds (P > .05) and 1.9 ± 4.7 seconds (P > .05) in the HTS and control groups, respectively. These results did not differ statistically between the HTS and control groups., Conclusions: These results suggest the HTS is effective for alleviating pain and improving physical performance in women with risk factors for knee OA. However, the HTS does not appear to be superior to low-load resistance training for improving muscle strength, pain relief, or physical function., Clinical Trial Registration Number: NCT02802878., Level of Evidence: I., (Copyright © 2018 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.)

Ergometers are safe devices for patients and elderly individuals, as the exercise intensity can be controlled. Moreover, ergometer exercises, which remove the load from body weight on the leg joint, would better reflect training conditions in locations where the force of gravity is lower than that on Earth, such as the International Space Station or on the surface of Mars. The purpose of this study was not only to validate an ergometer exercise model for measuring oxygen uptake and knee joint reaction force by comparison with experimental results, but also to consider a strategy for electrically stimulating leg joint muscles to modulate them under altered gravity.

The purpose of this study is to examine the usefulness of a walking assist system using electrical stimulation. Thirty-two elderly people (18 men and 14 women) having no medical problems and five healthy young men participated in the study. The electrical stimulation was carried out in two cases: 1) hybrid training (HYBT) for the elderly subjects, 2) assisted walking aimed at eventual application in elderly individuals. The intensity of the electrical stimulation is 80% in case 1) and three patterns of 60%, 70%, and 80% of the measured maximum tolerable voltage (mMTV) in case 2). The HYBT effectiveness was the same or greater than that of weight machine training (WMT), and could improve the motor function of the lower limbs. During the assisted walking, the peak value of the vertical acceleration of the third lumber vertebra increased in contrast with the non-assisted walking. Steps and changes in the peak acceleration values in the sagittal plane also showed a tendency to increase due to the electrical stimulation. These results suggest that electrical stimulation can contribute to restore the weakened physical function of elderly individuals. The restoration will reduce the risk of falls and increase the daily activities.

We have developed a "hybrid training system" (HTS) that is designed to maintain the musculoskeletal system of astronauts by using an electrically stimulated antagonist to resist the volitional contraction of agonist muscles in weightlessness. In other words, electrical stimulation generates a resistive force instead of gravity. HTS will become a useful back-up for the standard training device in the International Space Station, or a useful training device in the small space ship for the exploration of the Moon and Mars.

Conventional neuromuscular electrical stimulation (NMES) results in surface muscle contraction but high electrical stimulation intensity is required to activate the deep muscles. Therefore, NMES is not useful for training at complicated sites such as the forearm. To make NMES more effective we developed a hybrid training method (HYB), consisting of electrically stimulated antagonists to resist agonist muscle contractions. The purpose of this study was to compare the effects of HYB on the forearm as compared with NMES alone, and to determine whether HYB had any adverse effects on complex hand movements. Thirty subjects were randomly distributed into three groups: a HYB program group, an isometric electrical stimulation group (ES), and a control group (CN). Subjects trained 3 times a week for 6 weeks. Each session consisted of 10 sets of 10 reciprocal 2-sec wrist flexions and extensions separated by 1-min rest intervals. Wrist flexion/extension torques, grip strengths (GS), forearm flexor/extensor cross sectional areas (CSA), and hand dexterity (Purdue Pegboard (PEG) test, finger tapping (Tapping) test were measured. The HYB group demonstrated statistically significant increases in wrist extension torques (22.8%, p<0.01), forearm flexor CSA (9.6%, p<0.01), and in forearm extensor CSA (5.1%, p<0.05) at the end of training. There was no increase in torque or CSA in the ES or CN groups. Hand dexterity showed no significant differences in any of the three groups. HYB had no adverse effect on hand function and was more effective in forearm training than NMES alone.

Weightless environments such as prolonged bed rest and spaceflight are associated with dramatic losses of muscle volume and bone mass that hinder patients' or astronauts' health and reintegration into daily life. It is important that the countermeasure is effective for slow twitch fiber, and adds mechanical stress to a bone. So, we developed the hybrid training method (HYB) as a countermeasure of this musculoskeletal atrophy, which uses the contraction produced in a muscle by electrical stimulation of antagonist to resist the volitional contraction of agonist. HYB has several features. These include ; 1) simple device, 2) simultaneous contractions both agonist and antagonist musculature, 3) volitional contraction of deep layers of muscle, 4) longitudinal bone force loads. Several studies reported that, this HYB was tested successfully for increasing muscles strength and hypertrophy in the upper and lower extremities. And, a wearable HYB apparatus with a virtual reality control system was developed. Now, we are developing the hybrid ergometer with virtual reality system, which training can play while playing a game at home.

Introduction: A variety of techniques have been used with variable success in an attempt to reverse the loss of muscle strength, bulk, and endurance that occurs during spaceflight. This study was designed to evaluate a new "hybrid" approach that uses the resistance provided by an electrically stimulated antagonist muscle to resist the volitional contraction of its agonist., Methods: There were 20 subjects who were randomized into 3 groups that received either the new hybrid program (HYB), isotonic weight training (WT), or isometric electrical stimulation (ES). Subjects trained 3 times per week for 8 wk with each session consisting of their non-dominant upper extremity performing 10 sets of 10 reciprocal 2-s elbow flexion and extension contractions separated by 1-min rest intervals. Elbow flexion\extension torques and biceps\triceps cross-sectional areas (CSA) were measured at the beginning, midpoint, and end of training as well as at follow-up 4 wk later., Results: The HYB group demonstrated statistically significant increases in elbow flexion and extension torques (56% and 31%, respectively) at the end of training that were similar to or larger than the gains in the other groups with benefits that persisted at follow-up 4 wk later. Muscle CSA increases in the HYB group (10%) were comparable or larger than those in WT and ES subjects., Conclusions: These results suggest that HYB training may be an effective way to maintain and increase muscle bulk and strength for patients during bed rest, as well as astronauts in space.