Relationship between respiratory muscle strength and dynamic balance in older persons requiring care or support: Focusing on the maximal single step length test and maximal double step length test as dynamic balance indices.

BACKGROUND: Falls are a major health problem. The relationship between dynamic balance related to falls and respiratory muscle strength related to sarcopenia and frailty is poorly understood. RESEARCH QUESTION: How do dynamic balance measures, such as maximal single step length test (MSL) and maximal double step length test (MDST), and respiratory muscle strength measures, such as maximal inspiratory (PImax) and maximal expiratory (PEmax), related to the requirement for long-term care or support in older people who live in the community? METHODS: This was a cross-sectional study of 39 older people (17 men, 22 women) aged ≥ 65 years community-dwelling who were certified as requiring long-term care or support under the Japanese system. The participants' PImax, PEmax, MSL, and MDST results were recorded. The measurement data were evaluated using Pearson's correlation coefficients and multiple regression analysis. RESULTS: MDST showed a positive correlation with PImax (r = 0.430, p = 0.006) but no correlation with PEmax. MSL showed no correlation with PImax or PEmax. A positive correlation was found between MDST and MSL (r = 0.851, p < 0.001), and multiple regression analysis with MDST as the dependent variable and PImax and MST as independent variables showed significant differences for MSL (p < 0.001) and PImax (p = 0.027). SIGNIFICANCE: In older people requiring long-term care or support, MDST had a greater association with inspiratory muscle strength compared with MSL. These results suggest the importance of inspiratory muscle strength training and MDST assessment in the prevention of falls in older people requiring long-term care or support.

Four minutes of capacitive and resistive electric transfer therapy increased jump performance.

Capacitive and resistive electric transfer (CRET) therapy can improve flexibility and increase muscle activity and may be useful as a warm-up technique. This study examined the effects of short-time CRET on jump performance. Thirty healthy men (age range, 20-40 years) were randomly divided into passive (n = 15) and active (n = 15) warm-up groups. The participants and statisticians were blinded to the participant allocation. The passive warm-up group underwent 4 min of CRET therapy on their posterior lower legs. The active warm-up group performed stretching and jogging for 4 min. Calf muscle temperature and rebound jump (RJ) index were measured before and after the intervention. The mean (± standard deviation) muscle temperature increased by 2.0 ± 0.5°C and 1.4 ± 0.6°C in the passive and active warm-up groups, respectively (p < 0.05). RJ index increased significantly in both groups (p < 0.05). Therefore, passive warm-up using CRET may help avoid energy loss while increasing the muscle temperature in a short time when compared with traditional active warm-up techniques.

Capacitive and resistive electric transfer (CRET) is a device with deep thermal effect. CRET therapy can improve flexibility and increase muscle activity and may be useful as a warm-up technique. This study examined the effects of short-time CRET on jump performance. Thirty healthy men (age range, 20­40 years) were randomly divided into passive (n=15) and active (n=15) warm-up groups. The passive warm-up group underwent 4min of CRET therapy on their calf. The active warm-up group performed stretching and jogging for 4min. Calf muscle temperature and jump performance were measured before and after the intervention. The mean (± standard deviation) muscle temperature increased by 2.0±0.5°C and 1.4±0.6°C in the passive and active warm-up groups, respectively (p<0.05). Jump performance increased significantly in both groups (p<0.05). Therefore, passive warm-up using CRET may help avoid energy loss while increasing the muscle temperature in a short time when compared with traditional active warm-up techniques.

Relationship between walking speed, respiratory muscle strength, and dynamic balance in community-dwelling older people who required long-term care or support and used a daycare center.

Background: Focusing on the relationship between frail older people and gait speed is vital to minimize the need for long-term care or increased support. The relationship between gait speed, respiratory muscle strength, and dynamic balance, is not well understood in older people requiring long-term care or support. Therefore, this study aimed to provide new insights into the relationship between gait speed, respiratory muscle strength, and dynamic balance in community-dwelling older people who required long-term care or support and used a daycare center. Methods: This was a cross-sectional study of 49 community-dwelling older people (21 men, 28 women) aged ≥65 years who were certified as requiring long-term care or support under the Japanese system. The participants' maximal inspiratory pressure (PImax), maximal expiratory pressure (PEmax), walking speed (maximal and normal walking speed), and maximal double-step length test (MDST) results were recorded. The measurement data were evaluated using Pearson's correlation coefficient and multiple regression analysis. Results: Pearson's correlation coefficient revealed correlations between PImax and the following: maximal walking speed (r = 0.606, p < 0.001), normal walking speed (r = 0.487, p < 0.001), and MDST (r = 0.435, p = 0.002). Correlations were also observed between PEmax and the following: maximal walking speed (r = 0.522, p < 0.001), normal walking speed (r = 0.467, p < 0.001), and MDST (r = 0.314, p = 0.028). Moreover, a correlation was found between MDST and both maximal walking speed and (r = 0.684, p < 0.001) and normal walking speed (r = 0.649, p < 0.001). The effect size was 0.379. Multiple regression analysis using a forced entry method with maximal walking speed as the dependent variable showed that maximal walking speed was significantly associated with MDST (p < 0.001) and PEmax (p = 0.036), with an effect size of 0.272. The model's adjusted coefficient of determination was 0.593 (p < 0.001). Multiple regression analysis using a forced entry method with normal walking speed as the dependent variable showed that normal walking speed was significantly associated with MDST (p < 0.001) and PEmax (p = 0.021), with an effect size of 0.272. The model's adjusted coefficient of determination was 0.497 (p < 0.001). Multiple regression analysis using a forced entry method with MDST as the dependent variable showed that MDST was significantly associated with PImax (p < 0.025), with an effect size of 0.243. The model's adjusted coefficient of determination was 0.148 (p = 0.017). Conclusions: Respiratory muscle strength and dynamic balance were related to walking speed in older people requiring long-term care or support.

Comparison of the effect of respiratory muscle strength on dynamic and static balance assessment between sarcopenia and non-sarcopenia groups.

[Purpose] We compared differences in the association between respiratory muscle strength and static and dynamic balance in sarcopenia and non-sarcopenia groups, for fall risk assessment. [Participants and Methods] The study included 37 participants aged ≥65 years, who were certified to receive long-term care. Inspiratory and expiratory muscle strength, hand grip strength, Timed Up and Go Test scores, and one-leg standing task scores were recorded. Pearson's correlation coefficients and multiple regression analysis were used for data analysis. [Results] Only the expiratory muscle and hand grip strength were correlated in the sarcopenia group. Expiratory and inspiratory muscle strength was correlated with both one-leg standing task scores and hand grip strength, and inspiratory muscle strength was correlated with the Timed Up and Go Test scores in the non-sarcopenia group. Multiple regression analysis revealed that expiratory muscle strength was an explanatory variable for the one-leg standing task and inspiratory muscle strength for the Timed Up and Go Test in the non-sarcopenia group. [Conclusion] Combined evaluation of expiratory muscle strength and the Timed Up and Go Test scores may be useful to assess the fall risk.

Effects of capacitive and resistive electric transfer therapy on pain and lumbar muscle stiffness and activity in patients with chronic low back pain.

[Purpose] In this study, we investigated the therapeutic effects of capacitive and resistive electric transfer therapy in patients with chronic low back pain. [Participants and Methods] The study included 24 patients with chronic low back pain (12 patients each in the intervention and sham groups). Pain intensity, superficial and deep lumbar multifidus stiffness and maximum forward trunk flexion and associated activation level of the iliocostalis (thoracic and lumbar component) and lumbar multifidus muscles were measured. [Results] Post-intervention pain intensity and muscle stiffness were significantly lower than pre-intervention measurements in the intervention group. However, no between-group difference was observed in the muscle activation level at the end-point of standing trunk flexion. [Conclusion] Our findings highlight a significant therapeutic benefit of capacitive and resistive electric transfer therapy in patients with chronic low back pain and muscle stiffness.

Elucidation of abductor digiti minimi activity in chronic ankle instability.

[Purpose] This study aimed to compare the muscle activity around the foot and ankle joints, notably of the abductor digiti minimi, between affected and unaffected sides of individuals with chronic ankle instability. [Participants and Methods] Twelve adult males with chronic ankle instability in one ankle (age, 27.7 ± 5.4 years; height, 172.5 ± 8.1 cm; weight, 67.5 ± 8.1 kg) were included and underwent surface electromyography assessments in multiple positions on both affected and unaffected sides. Measurements were obtained for eight muscles including the abductor digiti minimi. Each measurement included a 5-s segment of the stable waveform, with the root mean square-processed and normalized to the resting position set to 1. [Results] Abductor digiti minimi activity on the affected side was significantly reduced during maximal toe extension/abduction with both ankle dorsiflexion and plantarflexion. Peroneus longus activity on the affected side was significantly greater during maximal toe extension/abduction with ankle plantarflexion; peroneus longus and tibialis anterior muscle activities were significantly greater on the affected side during maximal toe extension/abduction with ankle dorsiflexion. [Conclusion] In the absence of load, muscle imbalance in the intrinsic and extrinsic muscles of the foot was suggested. However, no significant differences were observed under loading conditions.