'The multiple-sit-to-stand' field test for older adults: what does it measure?

Background: The need to predict decline in functional status in a large number of older adults has brought researchers and clinicians to develop easy-to-administer field tests. One of them is the 'multiple-sit-to-stand' (MSTS), which claims to measure leg strength.

Objective: To assess the extent to which the MSTS is a leg strength, leg endurance or general endurance test.

Methods: 49 independently functioning women (72.2 +/- 6.4 years) were assessed on the MSTS, on a submaximal stress test, and on strength and endurance of knee extensors measured by isokinetics. The knee extensors were selected, more than in other muscle groups responsible for movement of the lower extremity, as the largest range of motion, and the largest torques required while performing activities of daily living (ADL) is found in this group.

Results: The correlation of the MSTS with the stress test was moderate and significant but very low and nonsignificant with the isokinetic measurements.

Conclusions: The MTST is not able to predict strength of knee extensors, the leading group of leg muscles in ADL. If at all, it predicts general endurance rather than any measure--muscle strength or muscle endurance--of lower extremities. Longitudinal studies assessing the potential of the MSTS to predict deterioration in ADL in older adults are recommended, as well as studies assessing other factors related to both MSTS and ADL, such as muscle-nerve coordination affecting multiple joint activities.