Threshold of chair stand power necessary to perform activities of daily living independently in community-dwelling older women

Abstract

Purpose:

To determine (1) the reproducibility of measurements of chair stand mean power (CSMP), (2) the relationships of CSMP with age, height, body mass, and body mass index, and (3) to identify the threshold of CSMP below which performing activities of daily living (ADL) is limited in older women.

Methods:

Eighty-seven older women (70-88 years) were divided into an independent group (n = 48) who needed no assistance and a dependent group (n = 39) who needed assistance to perform ADL. The CSMP expressed in watts (velocity x load) for each repetition was assessed by a device that measures mean velocity.

Results:

The intraclass correlation coefficient for CSMP suggested a high level of reproducibility (intra-class correlation coefficient = 0.88-0.92, P < .05). Relationships existed between CSMP and age (r = -0.37; P < .001), CSMP and height (r = 0.31; P < .001), CSMP and body mass (r = 0.43; P < .001), and CSMP and body mass index (r = 0.30; P < .001). A receiver operator characteristic curve analysis revealed the optimal threshold criteria; a CSMP of 214 watts resulted in the highest combination of sensitivity (82.1%) and specificity (81.2%).

Conclusion:

The threshold of CSMP below which assistance is required to perform ADL in community-dwelling older women was identified.