Older adult residents in disaster public housing had lower muscle function and mobility compared to non-residents: A cross-sectional study.

Abstract

Older adults who experienced post-disaster relocation are at risk of reduced muscle function and mobility due to changes in living environments. This study aimed to compare muscle morphology and physical function between older adults residing in disaster public housing (DPH) and those living in their own homes (Control: CON) in Kesennuma City, following relocation processes after the 2011 Great East Japan Earthquake. Fifty-two older participants were recruited from three wards of Kesennuma City and divided into DPH (n = 18; age: 78.8 ± 7.2 y, height: 153.0 ± 9.6 cm, weight: 56.0 ± 11.8 kg, BMI: 23.8 ± 3.9 kg/m²) and CON (n = 34; age: 75.0 ± 6.6y, height: 153.2 ± 6.8 cm, weight: 54.4 ± 7.6 kg, BMI: 23.2 ± 2.7 kg/m²) groups based on the survey results. The measurement variables were blood pressure, heart rate, muscle cross-sectional area, muscle thickness, echo intensity, handgrip strength, maximal voluntary contraction (MVC), rate of force development (RFD; 0-50 ms, 0-100 ms, 0-150 ms, 0-200 ms, 0-250 ms, 0-300 ms) of knee extension, and locomotive syndrome risk test (comprising the two-step test, stand-up test, and 25-Question Geriatric Locomotive Function Scale). The MVC was significantly lower in the DPH group (p = 0.043). The RFD was significantly lower in the DPH group at each time point (p < 0.05). In addition, the two-step test was significantly lower in the DPH group (p < 0.001). The other variables did not show significant differences between the groups. Residents in DPH were associated with decreased muscle strength and mobility, suggesting that post-disaster relocation environments may contribute to the decline of physical function and performance.