Treadmill training improves gait performance and reduces fall risk in older adults; however, inter-individual variability in training response has been reported. Insufficient adaptation to treadmill walking may limit training effectiveness and potentially increase fall risk. This study aimed to identify baseline gait characteristics associated with adaptation to treadmill walking in healthy older adults. Seventeen older adults walked on a treadmill at 2.7 km/h for 5 min while wearing a triaxial accelerometer on the lower trunk and a foot switch on the right shoe. Walking data were segmented into ten 30-s bins. Treadmill adaptation was defined as the slope of the stride-time coefficient of variation (CV) across bins. Baseline gait characteristics were calculated from the first three bins and included the root mean square of mediolateral acceleration (RMS_ML; magnitude of mediolateral trunk acceleration), the mediolateral harmonic ratio (HR_ML; temporal symmetry), and stride-time CV (temporal consistency). Spearman's and exploratory partial Spearman's correlations adjusted for comfortable overground walking speed were performed. Treadmill adaptation was significantly correlated with baseline stride-time CV (ρ = -0.56) and RMS_ML (ρ = 0.52). After adjusting for comfortable walking speed, only RMS_ML remained significant (ρ = 0.50). Additionally, HR_ML demonstrated a significant correlation only after speed adjustment (partial ρ = -0.58). These findings suggest that lower mediolateral trunk acceleration at baseline is associated with early temporal stabilization during treadmill walking in healthy older adults.

Background A clinical tool that evaluates factors associated with symptomatic knee osteoarthritis (OA) based on modifiable factors is lacking. This study aimed to develop a machine learning-based clinical assessment tool using modifiable factors to identify factors associated with symptomatic knee OA and to determine its accuracy. Methods This study included 429 participants (81.8% women; age, 69.0 ± 5.3 years) from the Nagahama Study who were ≥60 years old and had radiographically confirmed knee OA. A Knee Society Knee Scoring System 2011 symptom score of <23 points defined symptomatic knee OA. Participants were randomly assigned to training (70%) and test (30%) datasets. A machine learning model was developed using Extreme Gradient Boosting with 27 variables, and the SHapley Additive exPlanation (SHAP) values were used to assess feature importance. The top 8 features were translated into a 100-point clinical scoring tool weighted by their SHAP contributions. The cutoff value indicating symptomatic knee OA in the clinical assessment tool was determined using receiver operating characteristic analysis, and model performance was evaluated in both datasets. Results The clinical assessment tool consisted of low back pain, OA severity, depressive tendencies, knee flexion/extension range of motion, knee extension and hip abduction strength, and lower limb muscle quality. The model showed moderate discriminative performance (AUC 0.771 and 0.773 in the training and test datasets, respectively), with a cutoff point of 47. Conclusion The proposed clinical assessment tool may provide a structured framework for assessing modifiable factors associated with symptomatic knee OA, reflecting their contribution to current symptom status.

Objective:To assess the effectiveness of home-based self-rehabilitation using a portable electrical muscle stimulation (EMS) device for improving severe sarcopenia by improving lower extremity function. Design:The effect of 4 weeks of EMS training on improving lower extremity function was compared between patients divided into 2 groups based on baseline lower extremity function. Self-rehabilitation was carried out with a portable EMS device, the SIXPAD Foot Fit, and each session lasted 15-23 minutes. Lower extremity function was assessed with the Short Physical Performance Battery (SPPB). Setting:University hospital. Participants:The study included 50 older outpatients (N=50) with a mean age of 75 years; 98% had hepatobiliary cancer, and 38% were men. Interventions:Not applicable. Main Outcome Measures:Patients were divided into 2 groups based on baseline SPPB value (SPPB ≤ 9 or SPPB >9). Lower extremity function was observed prospectively during 4 weeks of home-based self-rehabilitation. Results:EMS was used consistently, with a median duration of use of 28 days. In the baseline SPPB>9 group, lower extremity function was not significantly improved (SPPB, 11.0-12.0; P=.290). In contrast, significant improvement was observed in the baseline SPPB ≤ 9 group, and the total score (SPPB score, 8.0-9.0; P=.001) and 2 of its 3 components, balance (balance score, 3.0-4.0; P=.009) and gait speed (gait speed score, 3.0-4.0; P=.002), improved significantly. Sit-to-stand ability did not improve (Sit-to-stand score, 1.0-2.0; P=.060). As a result, the proportion of patients with severe sarcopenia was initially 66.7% but decreased significantly to 36.4% (P=.002). Conclusions:A home-based, self-rehabilitation program using a portable EMS device may improve lower extremity function and attenuate sarcopenic status in older patients with cancer with reduced lower extremity function.

BACKGROUND:The knee extension deficit is known to occur with an increase in lumbar kyphosis. This study aimed to determine the association of knee extension deficit and lumbar kyphosis with knee symptoms and functional activities in patients with Knee Osteoarthritis (KOA). METHODS:Four hundred forty-eight participants aged 60 or over with radiographic KOA, all local community residents, were included in the analysis. The Knee Scoring System (KSS) was used to assess the functional abilities and symptoms. The knee extension angle was measured using a goniometer, and the lumbar spine angle was measured using Spinal Mouse, which is a noninvasive skin surface device. The associations between KSS symptoms or function scores with the presence or absence of knee extension deficit and lumbar kyphosis was evaluated using the multiple regression analysis. Another multiple regression analysis was conducted to clarify the effect of the coexisting knee extension deficit and lumbar kyphosis on KSS scores. RESULTS:The presence of knee extension deficit (β = -2.67; 95 % confidence interval [95 % CI]: -5.08, -0.27; p = 0.03) and lumbar kyphosis (β = -6.15; 95 % CI: -9.44, -2.86; p < 0.01) were associated with the KSS function score. Furthermore, the coexisting knee extension deficit and lumbar kyphosis significantly decreased the KSS function score (β = -10.24; 95 % CI: -15.1, -5.37; p < 0.01). However, the interaction between knee extension deficit and lumbar kyphosis was not statistically significant (p = 0.25). The KSS symptom score was not associated with knee extension deficit or lumbar kyphosis in either analysis. CONCLUSIONS:Our findings indicate that the coexisting knee extension deficit and lumbar kyphosis are an adverse clinical indicator associated with functional impairments in patients with KOA. STUDY DESIGN:Retrospective clinical study.

Knee pain is a characteristic symptom of early-stage knee osteoarthritis. Recently, the association between knee symptoms and infrapatellar fat pad (IFP) degeneration has garnered attention. This study aimed to clarify the association between ultrasound-derived size and echo intensity (EI) in the IFP and knee symptoms. A total of 163 community-dwelling older individuals (women, n = 106; age, 75.1 ± 7.0 years) participated. An ultrasound imaging device was used to assess the area and EI of the superficial and deep parts of the central, medial, and lateral IFP and presence of medial meniscal extrusion (MME) and medial tibial osteophytes. Based on the 2011 version of the Knee Society Knee Scoring System (KSS) symptoms category, the participants were classified into a symptomatic (KSS symptom score < 23, n = 74) or asymptomatic (KSS symptom score ≧23, n = 89) group. Logistic regression analyses were performed with groups as dependent variables and EI and area of the IFP as independent variables. EI of the superficial part of the medial IFP was significantly associated with knee symptoms, adjusting for age, sex, body mass index, MME, and medial osteophytes (p < 0.05). MME was also significantly associated with knee symptoms (p < 0.05). EI of the other parts, area of any parts, and medial osteophytes were not associated with knee symptoms. These findings suggested the utility of evaluating EI on the superficial part of the medial IFP and MME as the articular structures associated with knee symptoms.

BACKGROUND:Gait characteristics of spatiotemporal parameters of knee osteoarthritis (OA) using large sample of patients with various radiographic severities and asymmetry have not been studied previously. OBJECTIVE:This study aimed to determine the disease-specific gait characteristics of knee OA and assess the spatiotemporal gait parameters associated with functional disability. METHOD:The data was extracted from the Nagahama study and included 1591 participants aged ≥ 60 years, who underwent knee radiography and gait analysis. Of these, 998 (62.7 %) were assigned to healthy control group and 593 (37.3 %) to knee OA group. Gait speed, cadence, stride length, step length asymmetry, and step-time variability were measured using wearable inertial sensor. The Knee Scoring System (KSS) was used to assess functional disability. Logistic regression analysis was performed, with group variables as dependent variables and gait parameters as independent variables. In knee OA group, multiple regression analysis was performed with KSS score as dependent variable and gait parameters as independent variables after adjusting for potential confounders. RESULTS:Step-time variability was associated with knee OA (adjusted odds ratio [OR], 1.08; 95 % confidence interval [CI], 1.00-1.15; p = 0.037). Lower gait speed (Beta [B]=13.60; 95 %CI, 4.41-22.80; p = 0.004) and higher step-time variability (B=-0.82; 95 %CI, -1.40 to -0.24; p = 0.005) were associated with a decrease in KSS score in knee OA. CONCLUSION:These findings suggest that higher step-time variability is a specific gait characteristic of knee OA and is a negative factor associated with functional disabilities. The assessment of step-time variability is a useful indicator for screening abnormal gait patterns in knee OA.

BACKGROUNDS:Locomotive syndrome is a condition in which a person is at risk of requiring nursing care due to musculoskeletal disorders. The 25-question Geriatric Locomotive Function Scale (GLFS-25) was developed to determine the severity of locomotive syndrome. In this study, we aimed to determine the prognostic significance of the GLFS-25 for all-cause mortality. METHODS:The study participants consisted of 3,447 community residents aged ≥65 years. All-cause mortality was determined using residential registry records. Skeletal muscle mass assessed via bioimpedance methods was considered in the analysis as a confounding factor. RESULTS:During a mean follow-up period of 3,236 days (30,566 person-years), 288 cases of all-cause mortality occurred. When participants were categorized by the GLFS-25 score [grade 1: <7 points (n = 1,948); grade 2: ≥7 to <16 points (n = 894); grade 3: ≥16 points (n = 605)], their survival probability decreased linearly with increasing grade (log-rank test P = 0.014). In a Cox proportional hazards model adjusted for confounding factors, including low skeletal muscle mass, GLFS-25 grade 3 was identified as an independent risk factor for all-cause mortality (hazard ratio: 1.60; P = 0.007) in the subpopulation aged ≥70 years but not in the overall population (P = 0.062). The hazard ratio for all-cause mortality with GLFS-25 grade 3 and low skeletal muscle mass combined was 2.66 (P < 0.001). CONCLUSION:The GLFS-25 is independently associated with all-cause mortality in older adults. Using this questionnaire to assess locomotive syndrome could be useful for identifying individuals at risk.

This study aimed to determine the effects of walking-only intervention (walking was the only exercise in which people participated) on physical function, fall-related outcomes, and health-related quality of life in community-dwelling older adults. We conducted a systematic search across five electronic databases, assessing risk of bias using Minds Manual for Guideline Development. Meta-analyses were performed, and pooled standardized mean differences were calculated. Nine studies (a total of 1,309 participants) were included, showing that walking-only interventions improved walking endurance (standardized mean difference: 1.11, 95% confidence interval: [0.08, 2.15]) and health-related quality of life (standardized mean difference: 0.71, 95% confidence interval: [0.18, 1.25]). However, there were no significant improvements in other outcomes. The certainty of the evidence based on the Grading of Recommendations, Assessment, Development, and Evaluation approach for all outcomes was graded as very low, primarily due to significant inconsistency and imprecision. Our results suggest that walking-only intervention can be effective for enhancing walking endurance and health-related quality of life for community-dwelling older adults. Further studies are required to investigate the effects of walking-only intervention. This need stems from the limited number of randomized controlled trials, heterogeneous intervention settings and results, and the very low certainty of the evidence.

Background: Overall spinal curvature is evaluated by calculating the difference between the angles of lumbar lordosis (LL) and thoracic kyphosis (TK) and is expressed as LL minus TK (LL-TK). It is unclear whether LL-TK is associated with physical function in community-dwelling older adults and whether it is more relevant than TK or LL alone. Objective: This study aimed to identify whether LL-TK is associated with physical function in community-dwelling older adults, and whether it is strongly associated than TK or LL alone. Methods: The participants comprised 1,674 community-dwelling older adults who underwent physical assessments (women, n = 1,099; mean age, 67.4 +/- 5.3 years). As spinal alignment indices, TK and LL were measured using skin surface methods, and LL-TK was calculated as the difference between them. Decreased LL-TK indicated increased overall spinal curvature. Physical function was determined by measuring single-leg standing, five-times chair-stand, and usual gait speed. Stepwise multiple regression analyses were performed with each physical function as the dependent variable and spinal alignment indices as the independent variables, with adjustments. Results: Multiple regression analyses showed that single-leg standing (beta = 0.092, 95% confidence interval [CI] = 0.071 to 0.214, p < .001) and five-times chair-stand (beta=-0.142, 95% CI = -0.037 to -0.019, p < .001) were significantly associated with LL-TK, but not LL. Both LL-TK (beta = 0.121, 95% CI = 0.001 to 0.004, p < .001) and LL (beta = 0.087, 95% CI = 0.001 to 0.003, p = .003) were significant determinants of usual gait speed. Conclusions: This study showed that decreased LL-TK may be associated with poor physical function. This association may be stronger than that observed for TK or LL alone.

OBJECTIVE:We aimed to examine whether lower-limb muscle quantity and quality assessed by bioelectric impedance analysis (BIA) were associated with knee extension strength and whether the association differed with knee osteoarthritis (OA) severity. METHODS:We included 1,525 participants (63.6% women; mean ± SD age 68.0 ± 5.3 years) from the Nagahama Prospective Cohort. Knee extension strength was measured during maximum voluntary isometric contraction. Lower-limb muscle mass and the extracellular water (ECW)-to-intracellular water (ICW) ratio were used as indicators of muscle quantity and quality, respectively, and assessed via a BIA device. We executed multiple linear regression analyses to investigate the association of muscle quantity and quality with knee extension strength. Additionally, participants were classified into three groups with respect to OA severity and symptoms: control, early OA, and advanced OA groups; subgroup analyses were also executed. RESULTS:The muscle mass (P < 0.001) and ECW-to-ICW ratio (P = 0.009) were significantly associated with knee extension strength. In the subgroup analysis, the muscle mass was significantly associated with knee extension strength (P < 0.001), but there was no association between ECW-to-ICW ratio and knee extension strength (P = 0.731) in the control group. In the early OA and advanced OA groups, the muscle mass (both P < 0.001) and ECW-to-ICW ratio (early OA, P = 0.034; advanced OA, P = 0.015) were significantly associated with knee extension strength. CONCLUSION:Lower-limb muscle quality was associated with knee extension strength, and the association was stronger in patients with knee OA. These findings suggest that both muscle quantity and quality should be assessed to better understand muscle function in patients with knee OA.

Aim: The purpose of this systematic review and meta-analysis was to investigate the effects of low-intensity resistance training on knee extension strength with respect to intensity, frequency, duration and training site in community-dwelling older adults. Methods: A literature search was conducted for articles published up to December 2018 on PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Physiotherapy Evidence Database (PEDro), OTseeker and Ichushi-Web. Randomized controlled trials involving resistance training with <60 % one repetition maximum (1RM) in community-dwelling older adults aged 60 years and older were eligible. Results: In total, 7 studies involving 275 participants were included in the meta-analysis. The results showed significant improvements in knee extension strength with low-intensity resistance training [standardized mean difference (SMD) 0.62, 95 % confidence interval (CI) 0.32 to 0.91]. In subgroup analyses, significant improvements were observed in the group with intensity at 50-60 % 1RM (0.83, 0.46 to 1.19), but not in the group at 40 % or less 1RM (0.30, 95%CI: -0.08 to 0.68). Concerning frequency, there were significant improvements in knee strength for those receiving training three times (0.90, 0.52 to 1.27) and two times (0.36, 0.03 to 0.69) per week, with a significant difference between the groups (p = 0.04). Conclusions: Low-intensity resistance training should be considered as an effective intervention to improve knee extension strength in community-dwelling older adults. Older adults may show more improvement in knee extension strength if intensity of the training is set at 50-60 % 1RM and frequency of training is three times per week.

Biceps brachii muscle consists of a long head (BBL) and a short head (BBS). Shortening the BBL and BBS causes tendinopathy of the intertubercular groove and coracoid process. Therefore, it is necessary to stretch the BBL and BBS separately. This study aimed to determine the positions where the BBL and BBS were most stretched, using shear wave elastography (SWE). Fifteen healthy young males participated in the study. The shear elastic moduli of the BBL and BBS of the non-dominant arm were measured using SWE. The measurement positions were the resting position (shoulder flexion and abduction 0°) and four stretching positions.. The elbow was extended, and the forearm was pronated in all positions. Statistical analysis was performed using Wilcoxon's signed-rank test to compare the shear elastic moduli between the resting and stretched limb positions. In addition, Wilcoxon's signed-rank test was used to compare shear elastic moduli between the stretching positions that were significantly different compared to the resting position.. Results show that for BBL and BBS, shear elastic moduli were significantly higher in the shoulder extension + external rotation and shoulder horizontal abduction + internal rotation positions than in the resting position. Moreover, the shear elastic modulus of the BBL was significantly higher in shoulder extension + external rotation than in shoulder horizontal abduction + internal rotation. In contrast, the shear elastic modulus of the BBS was significantly higher in shoulder horizontal abduction + internal rotation than in shoulder extension + external rotation. The BBL and BBS were effectively stretched by shoulder extension + external rotation and horizontal abduction + internal rotation.

Objectives: This study aimed to systematically analyze the efficacy of therapeutic exercise on activities of daily living (ADL) and cognitive func-tion among older residents in long-term care facilities. Data Sources: PubMed, Cochrane Central of Register Trials, Physiotherapy Evidence Database, OTseeker, and Ichushi-Web were searched from inception until December 2018. Study Selection: Databases were searched to identify randomized controlled trials (RCTs) of therapeutic exercise for long-term care facility resi-dents aged 60 years and older, focusing on ADL and cognitive function as outcomes. Data Extraction: Two independent reviewers extracted the key information from each eligible study. Two reviewers independently screened and assessed all studies for eligibility, extracting information on study participants, details of interventions, outcome characteristics, and significant outcomes. Any discrepancies were resolved by a third reviewer. Data Synthesis: A total of 11 RCTs with 1280 participants were eligible for analyses. Therapeutic exercise had a significant benefit on ADL (stan-dard mean difference [SMD]=0. 22, 95% confidence interval [CI]: 0.02, 0.42, P=.03). Subgroup analyses indicated that interventions conducted >= 3 days per week [SMD=0.42, 95% CI 0.02, 0.82, P=.04] had a significant benefit on ADL. For cognitive function, group exercise and >= 3 day-s/week of intervention had a significant benefit (group exercise: mean difference [MD]=3.36, 95% CI 0.91, 5.80, P=.007; >= 3 days/week of inter-vention: MD=2.28, 95% CI 0.07, 4.49, P=.04).Conclusions: Therapeutic exercise conducted 3 or more days per week may be effective for improving ADL and cognitive function among older residents in long-term care facilities. This meta-analysis suggested that group exercise for cognitive functions was effective. However, the effec-tive method of intervention delivery for ADL was unclear. Archives of Physical Medicine and Rehabilitation 2023;104:812-23 (c) 2022 by the American Congress of Rehabilitation Medicine.

Objectives The concept of locomotive syndrome was proposed to highlight older adults who require nursing care services due to the malfunctioning of their locomotive organs. With the coming of a super-ageing society, there is a growing need to understand the relation between systemic chronic diseases and locomotive syndrome. Methods We analysed the second-visit dataset of the Nagahama Study. The association analysis was performed to identify the chronic diseases that were risk factors associated with the occurrence and the progression of locomotive syndrome in both the cross-sectional and longitudinal studies. Results Hypertension, stroke, coronary heart disease, rheumatoid arthritis, chronic renal failure, osteoporosis, anaemia, and gastroesophageal reflux disease were independently correlated with locomotive syndrome through the deterioration of body pain, social activity, and cognitive function in the cross-sectional study. Multiple chronic diseases had additive effects and significantly increased the risk of locomotive syndrome. In the longitudinal study, osteoporosis and kidney disease were significantly correlated with the worsening of the total GLFS-25 score. Conclusions Locomotive syndrome coexisted with various systemic chronic diseases, especially cardiovascular diseases. Osteoporosis and kidney disease were significantly correlated with the progression of locomotive dysfunction. The management of various chronic diseases may be useful to prevent locomotive syndrome and vice versa.

Abstract Nakao, S, Ikezoe, T, Taniguchi, M, Motomura, Y, Hirono, T, Nojiri, S, Hayashi, R, Tanaka, H, and Ichihashi, N. Effects of low-intensity torque-matched isometric training at long and short muscle lengths of the hamstrings on muscle strength and hypertrophy: A randomized controlled study. J Strength Cond Res 37(10): 1978–1984, 2023—This study investigated the effects of low-intensity torque-matched isometric training on muscle hypertrophy and strengthening at long (LL) and short muscle lengths (SL). Twenty-eight young subjects completed an 8-week hamstring isometric training program (30% of maximal voluntary contraction (MVC) × 5 s × 20 repetitions × 5 sets × 3 times/week) at 30° knee flexion (LL) or 90° knee flexion (SL). The cross-sectional area (CSA) of the hamstrings and MVC were measured before and after the intervention. The active torque because of muscle contraction was calculated by subtracting the passive torque at rest from the total torque (30% MVC). The active torque was significantly lower in the LL training group than in the SL training group (p < 0.01), whereas there was no between-group difference in total torque during training. For CSA and MVC at 30° knee flexion, the split-plot analysis of variance (ANOVA) showed no significant time × group interaction; however, it did show a significant main effect of time (p < 0.05), indicating a significant increase after training intervention. As for MVC at 90° knee flexion, there was a significant time × group interaction (p < 0.05) and a significant simple main effect of time in both the LL (p < 0.01; Cohen's d effect size [ES] = 0.36) and SL (p < 0.01; ES = 0.64) training groups. Therefore, low-intensity isometric training at LL can induce hypertrophy and strengthening, even in cases where the active torque production is lower than that at SL, whereas the training at SL may be more effective for muscle strengthening at SL.

Introduction: While shear modulus has been used as an index of muscle elongation, high costs prevent its general adoption. A more general indicator that can quantify muscle elongation non-invasively is needed to develop effective methods for stretching each muscle. The purpose of this study was to determine whether the echo intensity of the muscle changes with muscle elongation compared with the shear modulus.Methods: Sixteen healthy males (24.1 ± 2.8 years) participated in the study. Shear modulus and echo intensity of the medial gastrocnemius were assessed at 20° and 10° of ankle plantar-flexion, and 0°, 10°, and 20° of ankle dorsiflexion (presented as −20°, −10°, and 0°, +10°, +20°, respectively). Shear modulus was measured using ultrasound shear wave elastography. The echo intensity was quantified using the average grayscale value of a given region of interest (RoI) in longitudinal and transverse B-mode images. Grayscale analysis was performed using two RoIs: one which included as much of the muscle as possible (maximum RoI), and a rectangular one whose size and depth was identical for all images (rectangular RoI). Pearson’s correlation coefficients between either the shear modulus or echo intensity and the ankle angle and between the echo intensity and shear modulus were calculated separately for each participant.Results: Average Pearson’s correlation coefficient between shear modulus and ankle angle of the participants was 0.904. The average Pearson’s correlation coefficients between the echo intensity and ankle angle were estimated to be 0.797 and 0.222 for the maximum RoI and 0.698 and 0.323 for the rectangular RoI in the longitudinal and transverse images, respectively. The average Pearson’s correlation coefficients between the echo intensity and shear modulus were 0.684 and 0.514 for the maximum RoI, and 0.611 and 0.409 for rectangular RoI in the longitudinal and transverse images, respectively.Discussion: The results indicate that the echo intensity in the longitudinal image of the gastrocnemius, especially when assessed using the maximum RoI, increased with muscle elongation by passive ankle dorsiflexion. Therefore, assessment of the echo intensity using the maximum RoI in the longitudinal image might be useful for quantifying the muscle elongation.

Abstract Low-intensity training at long muscle-tendon unit lengths with a greater passive force may cause muscle swelling, which may be related to hypertrophy, even if the active force production is lower than that at short muscle-tendon unit lengths. This study compared muscle swelling after low-intensity torque-matched isometric exercises at long and short muscle-tendon unit lengths. Twenty-six volunteers performed isometric knee flexion exercises (30% of maximal voluntary contraction× 5 seconds×10 repetitions×9 sets) either at long or short lengths of the hamstrings (90° hip flexion and 30° knee flexion, or 90° hip and knee flexion, respectively). Active torque was calculated by subtracting passive torque from the total torque generated during exercise. Swelling-induced changes in cross-sectional area was assessed before and after exercise using ultrasonography. There was no between-group difference in the total torque during exercise; however, the active torque was significantly lower in the group trained at long than in the group trained at short muscle-tendon unit lengths. Muscle swelling occurred in both groups. The results suggest that exercise at long muscle-tendon unit lengths can cause similar muscle swelling as exercise at short muscle-tendon unit lengths, even in cases where active torque production is lower than that at short lengths.

Aim To clarify the difference in the longitudinal effects of physical exercise on health-related outcomes according to the baseline frailty status (frail or non-frail) in community-dwelling older adults. Methods Participants included 177 adults aged >= 65 years who carried out multicomponent physical exercises (strength, aerobic, gait and balance) for 40 min, one to three times per week, for 1 year at a day-care center. Bodyweight, comfortable walking speed, 6-min walking distance and Mini-Mental State Examination were measured at baseline and every 3 months. For longitudinal trend, we analyzed the change in scores from baseline for each outcome using the linear mixed effects model. Fixed effects included "group" (frail or non-frail), "time" (4 time points every 3 months, from 3 to 12 months) and "interaction between group and time." Results The effect sizes from baseline showed almost all positive values for each outcome. The linear mixed effects model showed significant effects on "interaction between group and time" in changes in bodyweight (P = 0.033), "group" in changes in walking speed (P = 0.013) and "time" in changes in the Mini-Mental State Examination (P < 0.001). Bodyweight showed a decreasing trend in the non-frail group after 3 months, unlike in the frail group. For walking speed, moderate effect sizes (d = 0.67-0.74) were sustained over time in the frail group, as did lesser effect sizes (d = 0.26-0.40) in the non-frail group. Conclusions Exercise-based multicomponent interventions were effective for both groups. The longitudinal effects on walking speed and bodyweight were greater in the frail group. Geriatr Gerontol Int 2022; center dot center dot: center dot center dot-center dot center dot.

OBJECTIVE:To examine the association of low back pain (LBP) and lumbar kyphosis with functional disabilities and knee symptoms in patients with knee osteoarthritis (OA).METHODS:We analyzed 586 participants (80.1% female; mean ± SD age 68.8 ± 5.2 years) from the Nagahama Study who were age ≥60 years and had radiographically confirmed knee OA. The Knee Society Knee Scoring System (KSS) was used to assess functional disabilities and knee symptoms. LBP was defined as the presence of any persistent back pain for more than 3 months. Lumbar kyphosis was determined by skin-surface methods using a computer-aided electronic device called the Spinal Mouse. Multiple linear regression analysis was used for assessing the association of LBP and lumbar kyphosis with the KSS scores. Subgroup analyses based on sex were also performed.RESULTS:LBP and lumbar kyphosis were independently associated with a lower KSS function score after adjustment for covariates (mean difference -4.96 [95% confidence interval (95% CI) -7.56, -2.36] points for LBP alone, mean difference -4.47 [95% CI -8.51, -0.43] points for lumbar kyphosis alone, and mean difference -13.86 [95% CI -18.86, -8.86] points for the coexistence of LBP and lumbar kyphosis, respectively). The coexistence of LBP and lumbar kyphosis in women was associated with a lower KSS symptom score (mean difference -4.49 [95% CI -6.42, -2.55] points).CONCLUSION:These findings suggest that both LBP and lumbar kyphosis are useful clinical signals indicating functional disability and knee symptoms in patients with knee OA.

Hirono, T, Ikezoe, T, Taniguchi, M, Tanaka, H, Saeki, J, Yagi, M, Umehara, J, and Ichihashi, N. Relationship between muscle swelling and hypertrophy induced by resistance training. J Strength Cond Res 36(2): 359-364, 2022-Muscle swelling immediately after resistance exercise may be induced by metabolic stress. The accumulation of metabolic stress is considered to promote muscle hypertrophy after several weeks of resistance training (RT). The purpose of this study was to determine the relationship between muscle swelling immediately after the first session of RT and muscle hypertrophy after a 6-week RT using ultrasonography. Twenty-two untrained young men performed knee extension resistance exercise consisting of 3 sets with 8 repetitions at a load of 80% of one repetition maximum for 6 weeks (3 d center dot wk(-1)). Muscle thickness of the quadriceps femoris was measured using ultrasonography device at 3 anatomical sites (proximal, medial, and distal sites) of the middle, lateral, and medial part of the anterior thigh. The sum of the muscle thickness at 9 measurement sites was used for analysis. Acute change in muscle thickness immediately after the first session of RT was used as an indicator of muscle swelling. Chronic change in muscle thickness after the 6-week RT was used as an indicator of muscle hypertrophy. A significant increase in muscle thickness was observed immediately after the first session of RT (8.3 +/- 3.2%, p < 0.001). After the 6-week RT, muscle thickness increased significantly (2.9 +/- 2.6%, p < 0.001). A significant positive correlation was found between muscle swelling and muscle hypertrophy (rho = 0.443, p = 0.039). This study suggests that the greater the muscle swelling immediately after the first session of RT, the greater the muscle hypertrophy after RT.