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.

Takumi Jiroumaru 
  Yutaro Hyodo 
  Michio Wachi 
  Nobuko Shichiri 
  Junko Ochi 
  Takamitsu Fujikawa

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.

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10.7717/peerj.16630