This study examined the effects and feasibility of a twice-weekly combined therapy of branched-chain amino acids (BCAAs) and exercise on physical function improvement in frail and pre-frail elderly people requiring long-term care. We used a crossover design in which the combination of exercise and nutritional interventions was carried out twice a week during cycles A (3 months) and B (3 months) and the exercise intervention alone was performed during the washout period. The exercise intervention entailed the following 5 training sets: 3 sets of muscle training at 30% of maximum voluntary contraction, 1 set of aerobic exercise, and 1 set of balance training. For the nutritional intervention, 6 g of BCAAs or 6 g of maltodextrin was consumed 10 min before starting the exercise. We determined upper and lower limb isometric strength, performance on the Functional Reach Test (FRT) and the Timed Up and Go test, and activity level. In the comparison between the BCAA group and the control group after crossover, the improvement rates in gross lower limb muscle strength (leg press, knee extension) and FRT performance were significantly greater (by approximately 10%) in the BCAA group. In the comparison between different orders of BCAA administration, significant effects were shown for the leg press in both groups only when BCAAs were given. The combination of BCAA intake and exercise therapy yielded significant improvements in gross lower limb muscle strength and dynamic balance ability.

Aim Factors related to instrumental activities of daily living disability in older adults with knee osteoarthritis are unclear. This study aimed to examine the discriminatory accuracy for the presence of instrumental activities of daily living disability in older adults with knee osteoarthritis by combining two factors of gait ability and pain status. Methods A cross‐sectional study was conducted on 114 patients with knee osteoarthritis aged ≥ 65 years. Participants were divided into instrumental activities of daily living disabled or non‐disabled groups. A logistic regression model was created with usual gait speed and knee injury and osteoarthritis outcome score‐pain subscale as independent variables for discriminating the presence of instrumental activities of daily living disability. The area under the receiver operating characteristic curve was inspected to determine discriminatory accuracy of the logistic regression model, usual gait speed, knee injury and osteoarthritis outcome score‐pain subscale. Results Of the 114 patients, 26 (22.8%) had instrumental activities of daily living disability. The area under the curves was 0.91 (95% confidence interval: 0.85–0.96) for the logistic regression model, 0.78 (95% confidence interval: 0.68–0.89) for usual gait speed, and 0.73 (95% confidence interval: 0.61–0.84) for knee injury and osteoarthritis outcome score‐pain subscale. Conclusions This study showed that gait speed and pain status were independent discriminatory factors and combining these factors to discriminate more accurately the presence or absence of instrumental activities of daily living disability in older adults with knee osteoarthritis was important. Geriatr Gerontol Int 2021; 21: 683–688.

BACKGROUND: The population of older adults with knee osteoarthritis (OA)-related disabilities is increasing globally. However, studies regarding instrumental activities of daily living (IADL) in older adults with knee OA are limited. OBJECTIVE: This study investigated the psychological factors associated with IADL disability in older adults with moderate to severe knee OA. METHODS: A cross-sectional study was conducted on 179 patients with knee OA aged ⩾ 65 years. The six-item short form of the Pain Catastrophizing Scale (PCS-6), the four-item short form of the Pain Self-Efficacy Questionnaire (PSEQ-4), and the fifteen-item Geriatric Depression Scale (GDS-15) were used to assess psychological factors. The participants were divided into IADL disabled and non-disabled groups. Binary logistic regression analyses were performed with the IADL disability status as the dependent variable. The PCS-6, PSEQ-4, and GDS-15 tools were included as independent variables in the logistic regression model. RESULTS: Of the 179 participants, 88 (49.1%) showed disability in conducting IADL. PSEQ-4 (odds ratio = 0.90, 95%; confidence interval = 0.82–0.99, p= 0.02) was a significant independent variable among all psychological factors. CONCLUSION: Even after controlling for cofounders, our study found that self-efficacy, assessed using the PSEQ-4, was related to IADL disability in older adults with moderate to severe knee OA.