Optimizing shoulder elevation assist rate in exoskeletal rehabilitation based on muscular activity indices: a clinical feasibility study.

BACKGROUND: Restoring shoulder function is critical for upper-extremity rehabilitation following a stroke. The complex musculoskeletal anatomy of the shoulder presents a challenge for safely assisting elevation movements through robotic interventions. The level of shoulder elevation assistance in rehabilitation is often based on clinical judgment. There is no standardized method for deriving an optimal level of assistance, underscoring the importance of addressing abnormal movements during shoulder elevation, such as abnormal synergies and compensatory actions. This study aimed to investigate the effectiveness and safety of a newly developed shoulder elevation exoskeleton robot by applying a novel optimization technique derived from the muscle synergy index. METHODS: Twelve chronic stroke participants underwent an intervention consisting of 100 robot-assisted shoulder elevation exercises (10 × 10 times, approximately 40 min) for 10 days (4-5 times/week). The optimal robot assist rate was derived by detecting the change points using the co-contraction index, calculated from electromyogram (EMG) data obtained from the anterior deltoid and biceps brachii muscles during shoulder elevation at the initial evaluation. The primary outcomes were the Fugl-Meyer assessment-upper extremity (FMA-UE) shoulder/elbow/forearm score, kinematic outcomes (maximum angle of voluntary shoulder flexion and elbow flexion ratio during shoulder elevation), and shoulder pain outcomes (pain-free passive shoulder flexion range of motion [ROM] and visual analogue scale for pain severity during shoulder flexion). The effectiveness and safety of robotic therapy were examined using the Wilcoxon signed-rank sum test. RESULTS: All 12 patients completed the procedure without any adverse events. Two participants were excluded from the analysis because the EMG of the biceps brachii was not obtained. Ten participants (five men and five women; mean age: 57.0 [5.5] years; mean FMA-UE total score: 18.7 [10.5] points) showed significant improvement in the FMA-UE shoulder/elbow/forearm score, kinematic outcomes, and pain-free passive shoulder flexion ROM (P < 0.05). The shoulder pain outcomes remained unchanged or improved in all patients. CONCLUSIONS: The study presents a method for deriving the optimal robotic assist rate. Rehabilitation using a shoulder robot based on this derived optimal assist rate showed the possibility of safely improving the upper-extremity function in patients with severe stroke in the chronic phase.

Estimation of minimal detectable change in the 10-meter walking test for patients with stroke: a study stratified by gait speed.

Objective: This study aimed to classify and calculate the minimal detectable changes (MDC) in gait time and gait speed in a 10-meter walking test (10MWT) in patients with stroke classified according to their gait speed. Methods: The participants were 84 patients with stroke. Their gait times were measured twice each at their comfortable gait speed (CGS) and maximum gait speed (MGS) on a 10-meter straight track, and gait speed was calculated using gait time. Participants were assigned to three speed groups based on their CGS: low-speed (<0.4 m/s; n = 19); moderate-speed (0.4-0.8 m/s; n = 29); and high-speed (>0.8 m/s; n = 36). For each group, first and second retest reliability and MDC of CGS and MGS were calculated using gait time and gait speed in the 10MWT. Results: MDCs in the 10MWT at CGS were: low-speed group, gait time 5.25 s, gait speed 0.05 m/s; moderate-speed group, gait time 2.83 s, gait speed 0.11 m/s; and high-speed group, gait time 1.58 s, gait speed 0.21 m/s. MDCs in the 10MWT at MGS were: low-speed group, gait time 7.26 s, gait speed 0.04 m/s; moderate-speed group, gait time 2.48 s, gait speed 0.12 m/s; and high-speed group, gait time 1.28 s, gait speed 0.19 m/s. Conclusion: Since the MDC of gait speed and gait time differ depending on the participant's gait speed, it is necessary to interpret the results according to the participant's gait speed when judging the effectiveness of therapeutic interventions.

Combined Ankle Robot Training and Robot-assisted Gait Training Improved the Gait Pattern of a Patient with Chronic Traumatic Brain Injury.

Background: : Walking disability caused by central nervous system injury often lingers. In the chronic phase, there is great need to improve walking speed and gait, even for patients who walk independently. Robot-assisted gait training (RAGT) has been widely used, but few studies have focused on improving gait patterns, and its effectiveness for motor function has been limited. This report describes the combination of "RAGT to learn the gait pattern" and "ankle robot training to improve motor function" in a patient with chronic stage brain injury. Case: : A 34-year-old woman suffered a traumatic brain injury 5 years ago. She had residual right hemiplegia [Fugl-Meyer Assessment-Lower Extremity (FMA-LE): 18 points] and mild sensory impairment, but she walked independently with a short leg brace and a cane. Her comfortable gait speed was 0.57 m/s without an orthosis, and her 6-m walk test distance was 240 m. The Gait Assessment and Intervention Tool (G.A.I.T.) score was 35 points. After hospitalization, ankle robot training was performed daily, with RAGT performed 10 times in total. Post-intervention evaluation performed on Day 28 showed: FMA-LE, 23 points; comfortable walking speed, 0.69 m/s; G.A.I.T., 27 points; and three-dimensional motion analysis showed ankle dorsiflexion improved from 3.22° to 12.59° and knee flexion improved from 1.75° to 16.54° in the swing phase. Discussion: : This is one of few studies to have examined the combination of two robots. Combining the features of each robot improved the gait pattern and motor function, even in the chronic phase.

Effects of the COVID-19 Pandemic on Physical Function of Community-Dwelling People with Disabilities in Japan.

In 2020, COVID-19 spread throughout the world, and international measures such as travel bans, quarantines, and increased social distancing were implemented. In Japan, the number of infected people increased, and a state of emergency was declared from 16 April to 25 May 2020. Such a change in physical activity could lead to a decline in physical function in people with disabilities. A retrospective study was conducted to determine the impact of the pandemic on the physical function of disabled persons living in the community. Data were collected at four points in time: two points before the declaration of the state of emergency was issued and two points after the declaration period had ended. Time series data of physical function at four points in time were compared for 241 people with disabilities. The mean age was 72.39 years; 157 had stroke, 59 musculoskeletal disease, and 26 other diseases. Overall, there was a long-term decrease in walking speed (p < 0.001) and a worsening of the Timed Up-and-Go (TUG) score (p < 0.001) after the period of the state of emergency. The TUG score worsened only in the group with a walking speed of 1.0 m/s or less before the state of emergency (p = 0.064), suggesting that this group was more susceptible.

Relationship between initial nutritional status and functional independence measures at discharge in subacute stroke.

OBJECTIVE: This retrospective study examined the association between nutritional status at admission and functional independence measure (FIM™) at discharge. MATERIALS AND METHODS: This study included 205 patients, aged ≥ 65, discharged from a convalescent ward between April 2017 and March 2018. The primary outcome was discharge FIMTM, and the secondary outcomes were the length of stay (LOS) and FIM efficiency. The explanatory variables included demographic data, stroke type, admission FIMTM, body mass index (BMI), controlling nutritional status (CONUT), and Geriatric Nutritional Risk Index (GNRI). Patients were divided into three groups based on BMI and GNRI scores and four groups based on the CONUT score. Univariate and multiple regression analyses were performed to predict discharge FIMTM. Kruskal-Wallis and Dunn's tests were also performed for intergroup comparisons. RESULTS: In the univariate analyses, age, sex, onset-to-admission interval, admission FIMTM, GNRI, and BMI (all factors were p<0.001) were significant explanatory variables for discharge FIMTM. In the multiple linear regression analysis, admission FIMTM, LOS, age, and onset-to-admission interval were significant explanatory variables (adjusted R2 = 0.791; p<0.001). Although those with poor nutritional status required a longer hospital stay, they achieved the same FIM gain as those without poor nutritional status. CONCLUSIONS: Nutritional status on admission did not affect the FIMTM at discharge in the convalescent ward. Patients with subacute stroke require adequate rehabilitation regardless of their nutritional status.

Role of dipeptidyl peptidase IV (DPP4) in the development of dyslipidemia: DPP4 contributes to the steroid metabolism pathway.

AIMS: We previously reported that dipeptidyl peptidase IV (DPP4)-deficient rats were susceptible to dyslipidemia induced by streptozotocin (STZ). Hence, it is suggested that DPP4 is important for lipid metabolism. MAIN METHODS: In this study, to verify the role of DPP4 in the development of dyslipidemia, we carried out a microarray analysis of the livers of STZ-treated wild-type and DPP4-deficient rats and showed that the expression levels of genes involved in metabolic processes (steroid metabolic processes and cellular lipid metabolic processes) were significantly altered by STZ treatment. KEY FINDINGS: In the wild-type rats, the expression of hydroxysteroid (17-beta) dehydrogenase 2 (Hsd7b2), which catalyzes sex steroid synthesis from cholesterol, was significantly increased by about 15-fold after STZ treatment; however, it did not change in the DPP4-deficient rats. In the STZ untreated group of DPP4-deficient rats, the expression levels of cytochrome P450, subfamily 51 (Cyp51) and sterol-C4-methyl oxidase-like (Sc4mol), which catalyze intermediate steps in cholesterol synthesis, were significantly elevated compared to those of other groups. Similar results were demonstrated in HuH7-cells after DPP4 overexpression or the addition of human sera containing DPP4. SIGNIFICANCE: DPP4 is crucial for regulating the expression of factors related to steroid metabolism such as Cyp51, Sc4mol, and Hsd17b2, and DPP4 deficiency or inhibition may cause dyslipidemia.

Altered dipeptidyl peptidase-4 activity during the progression of hyperinsulinemic obesity and islet atrophy in spontaneously late-stage type 2 diabetic rats.

Altered dipeptidyl peptidase-4 (DPP4) activity during the progression of late-stage type 2 diabetes was measured in Otsuka Long-Evans Tokushima fatty (OLETF) rats. Compared with OLETF rats subjected to 30% food restriction, food-satiated OLETF rats exhibited spontaneous hyperphagic obesity, insulin resistance, hyperglycemia, hyperinsulinemia, and increased plasma DPP4 activity during the early phase of the experiment (up to ∼30 wk). Subsequently, their plasma DPP4 activity as well as their body weight, body fat, and plasma insulin concentration declined to control levels during the late phase, resulting in excessive polyuria, proteinuria, dyslipidemia, pancreatic islet atrophy, hypoinsulinemia, and diabetes, which changed from insulin-resistant diabetes to hypoinsulinemic diabetes secondary to progressive islet insufficiency, and their fasting blood glucose level remained high. Since plasma DPP4 activity demonstrated significant positive correlations with body weight and the fasting plasma insulin level but not with the fasting blood glucose level during the late stage of diabetes, body fat and fasting plasma insulin levels may be useful factors for predicting the control of plasma DPP4 activity. In contrast, pancreatic DPP4 activity was significantly increased, and the expression of pancreatic insulin was significantly reduced in late-stage diabetic OLETF rats, suggesting that a relationship exists between the activation of pancreatic DPP4 and insulin depletion in pancreatic islet atrophy. In conclusion, it is suggested that plasma DPP4 activity changes in accordance with the progression of hyperinsulinemic obesity and pancreatic islet atrophy. DPP4 activity may play an important role in insulin homeostasis.

Increased plasma dipeptidyl peptidase IV (DPP IV) activity and decreased DPP IV activity of visceral but not subcutaneous adipose tissue in impaired glucose tolerance rats induced by high-fat or high-sucrose diet.

Several studies have investigated whether dipeptidyl peptidase IV (DPP IV) activity is correlated to the severity of diabetes; however, it remains unclear. To investigate the roles of DPP IV activity in metabolic abnormalities, impaired glucose tolerance rats were produced using a high-fat (HF) or high-sucrose (HS) diet. HF diet-fed rats obviously exhibited impaired glucose tolerance, with increases in subcutaneous and epididymal fat mass, insulin resistance and dyslipidaemia. In rats fed a HS diet rather than a normal diet, lower body weight and fasting blood glucose were observed temporarily in the early period after HS diet feeding; however, impaired glucose tolerance was evoked to some extent with an increase in epididymal fat mass. Both HF and HS diet-fed rats showed significantly higher plasma DPP IV activity than normal diet-fed rats, in the order of HF diet>HS diet>normal diet. HF and HS diets did not significantly affect DPP IV activity and mRNA expression in the kidney. On the other hand, HF, but not HS, diet caused a significant decrease in DPP IV activity in the liver as compared to the control. Of note, both HF and HS diets caused a significant decrease in DPP IV activity in epididymal fat, even though they did not change DPP IV activity in subcutaneous fat. In conclusion, HF or HS diet-induced impaired glucose tolerance with visceral fat accumulation may be interrelated with increased plasma DPP IV activity and decreased DPP IV activity of visceral but not subcutaneous adipose tissue.

Interrelationship of dipeptidyl peptidase IV (DPP4) with the development of diabetes, dyslipidaemia and nephropathy: a streptozotocin-induced model using wild-type and DPP4-deficient rats.

We examined the role of dipeptidyl peptidase IV (DPP4) in the development of diabetes, dyslipidaemia and renal dysfunction induced by streptozotocin (STZ). F344/DuCrlCrlj rats, which lack DPP4 activity, and wild-type rats were treated with STZ. Plasma DPP4 activity and biochemical parameters were measured until 42 days after STZ treatment. At the end of the experiment, renal function and DPP4 expressions of the kidney, liver, pancreas and adipose tissues were determined. Increases in blood glucose, cholesterol and triglycerides were evoked by STZ in both rat strains; however, the onset of hyperglycaemia was delayed in DPP4-deficient rats as compared with wild-type rats. By contrast, more severe dyslipidaemia was observed in DPP4-deficient rats than in wild-type rats after STZ treatment. Plasma DPP4 activity increased progressively with time after STZ treatment in wild-type rats. The kidney of wild-type rats showed decreased DPP4 activity with increased Dpp4 mRNA after STZ treatment. In addition, kidney weight, serum creatinine and excreted amounts of urinary protein, glucose and DPP4 enzyme were enhanced by STZ. DPP4-deficient rats showed increased serum creatinine in accordance with decreased creatinine clearance as compared with wild-type rats after STZ treatment. In conclusion, plasma DPP4 activity increased after STZ treatment, positively correlating to blood glucose. DPP4-deficient rats were resistant to developing diabetes, while susceptible to dyslipidaemia and reduction of glomerular filtration rate by STZ. DPP4 activation may be responsible for hyperglycaemia, lipid metabolism and preservation of renal function.