Hybrid Training System Consisting of Synchronized Neuromuscular Electrical Stimulation for Voluntary Exercise Using an Articular Motion Sensor.

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.

Impact of spinal surgery on locomotive syndrome in patients with lumbar spinal stenosis in clinical decision limit stage 3: a retrospective study.

BACKGROUND: Locomotive syndrome (LS) is characterized by reduced mobility. Clinical decision limit (CDL) stage 3 in LS indicates physical frailty. Lumbar spinal canal stenosis (LSS) is one of the causes of LS, for which lumbar surgery is considered to improve the CDL stage. This study aimed to investigate the efficacy of lumbar surgery and independent factors for improving the CDL stage in patients with LSS. METHODS: This retrospective study was conducted at the Department of Orthopaedic Surgery at our University Hospital. A total of 157 patients aged ≥ 65 years with LSS underwent lumbar surgery. The 25-Question Geriatric Locomotive Function scale (GLFS-25) was used to test for LS, and the Timed Up and Go test (TUG) was used to evaluate functional ability. Lower limb pain was evaluated using a visual analog scale. Patients with at least one improvement in the CDL stage following lumbar surgery were included in the improvement group. Differences in lower limb pain intensity between the groups were evaluated using the Wilcoxon rank-sum test. The Spearman's rank correlation coefficient was used to determine correlations between Δ lower limb pain and Δ GLFS-25. Logistic regression analysis was used to identify factors associated with improvement in LS. RESULTS: The proportion of patients with improved CDL stage was 45.1% (improvement/non-improvement: 32/39). Δ Lower limb pain was significantly reduced in the improvement group compared with that in the non-improvement group (51.0 [36.3-71.0] vs 40.0 [4.0-53.5]; p = 0.0107). Δ GLFS-25 was significantly correlated with Δ lower limb pain (r = 0.3774, p = 0.0031). Multiple logistic regression analysis revealed that TUG and age were significantly associated with improvement in LS (odds ratio, 1.22; 95% confidence interval: 1.07-1.47). CONCLUSIONS: Lumbar surgery effectively improved the CDL stage in patients with LSS. In addition, TUG was an independent factor associated with improvement in the CDL.

Phase angle is related to physical function and quality of life in preoperative patients with lumbar spinal stenosis.

Lumbar spinal stenosis (LSS) can interfere with daily life and quality of life (QOL). Evaluating physical function and QOL and helping patients to improve is the focus of rehabilitation. Phase angle (PhA) assessment is widely used to measure body composition and is considered an indicator of physical function and QOL. This study investigated the relationship between PhA and physical function, physical activity, and QOL in patients with LSS. PhA, handgrip strength, walking speed, Timed Up and Go test (TUG), Life Space Assessment (LSA), Prognostic Nutritional Index (PNI), Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ), and EQ-5D were assessed and statistically analyzed. The study included 133 patients with LSS. Multiple regression analysis of PhA adjusted for age, sex, and body mass index (Model 1) and for Model 1 + PNI (Model 2) showed significant correlations (P < 0.05) with handgrip strength, walking speed, TUG, and LSA. Regarding QOL, PhA was significantly correlated (P < 0.05) with lumbar function in JOABPEQ. PhA was associated with physical function and QOL in patients with LSS and might be a new clinical indicator in this population.

Effect of Cycling Exercise Resisting Electrically Stimulated Antagonist Muscle Contractions in Healthy Males.

A hybrid training system (HTS) combining antagonist muscle electrical stimulation and voluntary muscle contraction has been developed using eccentric antagonist muscle contractions with electrical stimulation as resistance to voluntary muscle contractions. We devised an exercise method using HTS combined with a cycle ergometer (HCE). The purpose of this study was to compare the muscle strength, muscle volume, aerobic functions and lactate metabolism of HCE and a volitional cycle ergometer (VCE). A total of 14 male participants performed exercise on a bicycle ergometer for 30 min per session, 3 times per week for 6 weeks. We divided 14 participants into an HCE group (7 participants) and a VCE group (7 participants). The workload was set at 40% of each participant's peak oxygen uptake (V.O2peak). Electrodes were placed over each motor point on the quadriceps and hamstrings. The V.O2peak and anaerobic threshold significantly increased before and after training when using HCE rather than VCE. The HCE group had significantly increased extension and flexion muscle strength at 180 degrees/s in post-training measurements over pre-training measurements. Knee flexion muscle strength at 180 degrees/s tended to increase in the HCE group compared to the VCE group. The quadricep muscle cross-sectional area was significantly increased in the HCE group compared to the VCE group. Additionally, the HCE group had significantly decreased maximal lactate, measured every 5 min during exercise at the end of study, between pre and post-training. Thus, HCE may be a more effective training method for muscle strength, muscle mass and aerobic functions at 40% of each participant's V.O2peak than conventional cycling exercise. HCE could be applied not only as aerobic exercise but also as resistance training.

The Effect of Walking Combined with Neuromuscular Electrical Stimulation on Liver Stiffness and Insulin Resistance in Patients with Non-alcoholic Fatty Liver Disease: An Exploratory Randomized Controlled Trial.

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/m2 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.

Balance dysfunction the most significant cause of in-hospital falls in patients taking hypnotic drugs: A retrospective study.

PURPOSE: Preventing falls in patients is one of the most important concerns in acute hospitals. Balance disorder and hypnotic drugs lead to falls. The Standing Test for Imbalance and Disequilibrium (SIDE) is developed for the evaluation of static standing balance ability. There have been no reports of a comprehensive assessment of falls risk including hypnotic drugs and SIDE. The purpose of this study was to investigate the fall rate of each patient who took the hypnotic drug and the factor associated with falls. METHODS: Fall rates for each hypnotic drug were calculated as follows (number of patients who fell/number of patients prescribed hypnotic drug x 100). We investigated the hypnotic drugs as follows; benzodiazepine drugs, Z-drugs, melatonin receptor agonists, and orexin receptor antagonists. Hypnotic drug fall rate was analyzed using Pearson's chi-square test. Decision tree analysis is the method we used to discover the most influential factors associated with falls. RESULTS: This study included 2840 patients taking hypnotic drugs. Accidents involving falls were reported for 211 of inpatients taking hypnotic drugs. Z-drug recipients had the lowest fall rate among the hypnotic drugs. We analyzed to identify independent factors for falls, a decision tree algorithm was created using two divergence variables. The SIDE levels indicating balance disorder were the initial divergence variable. The rate of falls in patients at SIDE level ≦ 2a was 14.7%. On the other hand, the rate of falls in patients at SIDE level ≧ 2b was 2.9%. Gender was the variable for the second classification. In this analysis, drugs weren't identified as divergence variables for falls. CONCLUSION: The SIDE balance assessment was the initial divergence variable by decision tree analysis. In order to prevent falls, it seems important not only to select appropriate hypnotic drugs but also to assess patients for balance and implement preventive measures.

The impact of sarcopenia on low back pain and quality of life in patients with osteoporosis.

PURPOSE: Osteoporosis combined with sarcopenia contributes to a high risk of falling, fracture, and even mortality. However, sarcopenia's impact on low back pain and quality of life (QOL) in patients with osteoporosis is still unknown. The purpose of this study is to investigate low back pain and QOL in osteoporosis patients with sarcopenia. METHODS: We assessed 100 ambulatory patients who came to our hospital for osteoporosis treatment. Low back pain was evaluated using the Visual Analogue Scale (VAS) with 100 being an extreme amount of pain and 0 no pain. The Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) score was used to assess QOL after adjustment for age, history of vertebral fracture, and adult spinal deformity. Differences in low back pain intensity assessed by VAS between groups were evaluated by the Willcoxon rank-sum test. Covariance analysis was used to assess QOL. All data are expressed as either median, interquartile range, or average, standard error. RESULTS: Patients were classified into the sarcopenia group (n = 32) and the non-sarcopenia group (n = 68). Low back pain intensity assessed by VAS was significantly higher in the sarcopenia group than in the non-sarcopenia group (33.0 [0-46.6] vs. 8.5 [0-40.0]; p < 0.05). The subscales of the JOABPEQ for low back pain were significantly lower in the sarcopenia group than in the non-sarcopenia group (65.0 ± 4.63 vs. 84.0 ± 3.1; p < 0.05). CONCLUSION: In this cross-sectional study, sarcopenia affected low back pain and QOL in ambulatory patients with osteoporosis. Sarcopenia may exacerbate low back pain and QOL.

The effect of rotator cuff physical exercise combined with electrically stimulated antagonist on shoulder rotator cuff strength.

BACKGROUND: An elastic band (EB) is generally used with a low load for rotator cuff physical exercise, but the resulting increase in muscle strength is insufficient. We assessed the efficacy on external rotator muscle strength of the shoulder joint; of a hybrid training system (HTS) that resists the motion of a volitionally contracting agonist muscle using the force generated by its electrically stimulated antagonist vs. general rotator cuff exercise with EB. METHODS: Twenty healthy men with no shoulder joint disorders were randomized to 6 weeks of triweekly 10-min rotator cuff exercise with HTS or EB in a clinical research laboratory. Isokinetic concentric external rotator muscle strength at angular velocities of 60°/s and 180°/s (CON60, CON180, respectively) and isokinetic eccentric external rotator muscle strength at an angular velocity of 60°/s (ECC60) were measured as rotator cuff function before and after 6 weeks of intervention. RESULTS: There were no significant intergroup differences in baseline characteristics. There were statistically significant differences (p = 0.0358, p = 0.0213, respectively) in the increase in CON180 (mean ± SD) and ECC60 between the HTS group (Δ6.0 ± 6.0Nm, p = 0.015; Δ7.5 ± 4.7Nm p = 0.0007, respectively) and the EB group (Δ0.3 ± 5.2Nm, p = 0.8589; Δ1.8 ± 5.3 Nm p = 0.3133, respectively). There was a trend toward CON60 increasing in the HTS group (Δ4.7 ± 6.5Nm, p = 0.0494) which was greater than in the control group (Δ-0.9 ± 6.3Nm, p = 0.6637) (inter-group, p = 0.0677). CONCLUSIONS: The results of this study support the conclusion that HTS is more effective for increasing external rotator muscle strength more effectively than EB. HTS would be useful for rotator cuff physical exercise.

Electrically stimulated eccentric contraction during non-weight bearing knee bending exercise in the supine position increases oxygen uptake: A randomized, controlled, exploratory crossover trial.

It is well known that prolonged bed rest induces muscle weakness, muscle atrophy, cardiovascular deconditioning, bone loss, a loss of functional capacity, and the development of insulin resistance. Neuromuscular electrical stimulation is anticipated to be an interventional strategy for disuse due to bed rest. A hybrid training system (HTS), synchronized neuromuscular electrical stimulation for voluntary exercise using an articular motion sensor, may increase the exercise load though bed rest. We assessed oxygen uptake or heart rate during knee bending exercise in the supine position on a bed both simultaneously combined with HTS and without HTS to evaluate exercise intensity on different days in ten healthy subjects (8 men and 2 women) by a randomized controlled crossover trial. The values of relative oxygen uptake during knee bending exercise with HTS were significantly greater than those during knee bending exercise without HTS (7.29 ± 0.91 ml/kg/min vs. 8.29 ± 1.06 ml/kg/min; p = 0.0115). That increment with HTS was a mean of 14.42 ± 13.99%. Metabolic equivalents during knee bending exercise with HTS and without HTS were 2.08 ± 0.26 and 2.39 ± 0.30, respectively. The values of heart rate during knee bending exercise with HTS were significantly greater than those during knee bending exercise without HTS (80.82 ± 9.19 bpm vs. 86.36 ± 5.50 bpm; p = 0.0153). HTS could increase exercise load during knee bending exercise which is easy to implement on a bed. HTS might be a useful technique as a countermeasure against the disuse due to bed rest, for example during acute care or the quarantine for infection prophylaxis.

Grip Strength as a Predictor of the Functional Outcome of Hip-Fracture Patients.

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.

Electrically Stimulated Eccentric Contractions during Walking Increases Oxygen Uptake.

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.

Effects of a low-intensity resistance exercise program on serum miR-630, miR-5703, and Fractalkine/CX3CL1 expressions in subjects with No exercise habits: A preliminary study.

AIMS: Exercise is effective for the prevention of liver cancer. Exercise exerts biological effects through the regulation of microRNAs (miRNAs) and cytokines/myokines. We aimed to investigate the effects of low-intensity resistance exercise on serum miRNA and cytokine/myokine expressions in subjects with no exercise habits. METHODS: We enrolled seven male subjects with no exercise habits in this prospective before-after study. All subjects performed a low-intensity resistance exercise program (three metabolic equivalents, approximately 20 min/session). Serum miRNA expressions were evaluated using microarrays. We performed Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of differentially expressed miRNAs before and after exercise. Serum cytokine/myokine expressions were evaluated using a multiplex panel. RESULTS: All subjects completed the exercise program with no adverse events. In the microarray analysis, seven miRNAs showed a significant change between before and after exercise. Of these, microRNA (miR)-630 and miR-5703 showed a >1.5-fold increase (miR-630: 40.7 vs. 69.3 signal intensity, p = 0.0133; miR-5703: 30.7 vs. 55.9 signal intensity, p = 0.0051). KEGG pathway enrichment analysis showed that miR-630- and miR-5703-related genes were enriched in 37 and 5 pathways, including transforming growth factor-beta and Wnt signaling pathways, respectively. In the multiplex analysis, 12 cytokines/myokines showed significant alteration after exercise compared to before exercise. Of these, fractalkine/CX3CL1 showed the most significant up-regulation by exercise (94.5 vs. 109.1 pg/ml, p = 0.0017). CONCLUSIONS: A low-intensity resistance exercise program was associated with upregulation of serum miR-630, miR-5703, and fractalkine/CX3CL1 expressions in subjects with no exercise habits. Thus, even low-intensity exercise may alter miRNA and cytokine/myokine expressions in humans.

Hybrid Training System Improves Insulin Resistance in Patients with Nonalcoholic Fatty Liver Disease: A Randomized Controlled Pilot Study.

Insulin resistance is associated with the progression of nonalcoholic fatty liver disease (NAFLD). Insulin resistance is regulated by various cytokines, including interleukin-6 (IL-6), a proinflammatory myokine, and selenoprotein P (SeP), a liver-derived secretory hepatokine. High levels of IL-6 and/or SeP have been shown to contribute to insulin resistance, and exercise is a first-line therapy for NAFLD. We have developed a hybrid training system (HTS): a neuromuscular electrical stimulation device to enhance exercise results. We aimed to investigate the effects of HTS on insulin resistance as well as serum IL-6 and SeP in patients with NAFLD. This is a randomized, single-blind (assessor), controlled trial. Subjects with NAFLD walked on a treadmill with or without HTS (9 subjects each) for 30 minutes three times a week for six weeks (HTS vs. control group; median age 45 vs. 45; male/female 5/4 vs. 6/3). We examined subjects before the first session and at the end of the final session. Serum SeP levels were measured by ELISA which measures the fragment of SeP. In the HTS group, HOMA-IR values were significantly reduced compared to the control group (Δ-0.71 vs. Δ0.05; P < 0.05). IL-6 and SeP levels in serum were also significantly reduced compared to that of the control group (IL-6; Δ-0.6 vs. Δ0.29 pg/mL; P < 0.05, SeP; Δ-1288.5 vs. Δ-435.4 ng/mL; P < 0.05, respectively). In conclusion, we propose that HTS improves insulin resistance by reducing serum IL-6 and SeP levels in patients with NAFLD.

Impact of cancer rehabilitation on the prognosis of patients with hepatocellular carcinoma.

Sarcopenia is a prognostic factor for patients with hepatocellular carcinoma (HCC). Cancer rehabilitation (CR) improves patients' physical function and muscle mass. We investigated the effects of CR on the prognosis of patients with HCC. The present study was a prospective observational study, which analyzed 152 patients with HCC who underwent transcatheter arterial chemoembolization (TACE) between 2013 and 2016. Patients were classified into the CR (n=85) and control (n=67) groups. The effects of CR on muscle mass were evaluated by changes in the skeletal muscle index (SMI) before and after TACE. Independent factors associated with survival were evaluated by Cox regression analysis. Kaplan-Meier analysis was used to compare the survival rate between the CR and control groups. The difference in survival rate between the two groups was also examined after propensity score matching. SMI was significantly increased in the CR group compared with the control group. In Cox regression analysis, independent factors associated with survival were CR and Child-Pugh class A (estimate 1.760, 95% CI 0.914-3.226, P=0.001; estimate 1.602, 95% CI 0.426-2.998, P=0.0129). The survival rate was significantly higher in the CR group than in the control group (median 552 vs. 424 days; P=0.0359). The survival rate was also significantly higher in the CR group than that in the control group after propensity score matching (median 529 vs. 369 days; P=0.0332). CR was associated with prolonged survival in patients with HCC who underwent TACE. Patients with cancer are recommended to maintain physical activity even during cancer treatment.