Reliability and Validity of the Sit-to-Stand as a Muscular Power Measure in Older Adults

The study aims were to analyze the reliability and validity of the GymAware (TM) linear position transducer's velocity and power measures during the sit-to-stand, compared with the Dartfish 2D videography analysis, and to assess the relationship of age and handgrip strength with velocity and power in 48 older men and women (77.6 +/- 11.1 years). The results showed excellent agreement between GymAware- and Dartfish-derived sit-to-stand velocity (intraclass correlation coefficient(2-1) = .94 and power intraclass correlation coefficient(2-1) = .98) measures. A moderate and negative relationship was found between age and velocity (r = -.62; p < .001) and age and power (r = -.63; p < .001). A moderate and positive relationship was found between handgrip strength and velocity (r = .43; p = .002) and handgrip strength and power (r = .54; p < .001). The results show the GymAware velocity and power measures during the sit-to-stand in older adults to be reliable and valid.