Trunk movements in older subjects during sit-to-stand.

Sitting to standing (STS) is an activity that is performed many times during the course of a day and is an important prerequisite to the achievement of many functional goals. This article presents the results from a pilot study, the purpose of which was to develop a method for investigating the activity of sit-to-stand. The study describes STS timing and patterns of trunk movement during standing up in a population of 30 normal older adult subjects (mean age, 61.6 years; SD, 7.7 years). Data were gathered using a three-dimensional movement analysis system, CODA-3. Time taken to stand up was recorded, as were the trunk movements of pelvic and shoulder rotation, trunk lateral flexion, pelvic and shoulder lateral shift, and backward shoulder movement to achieve stance. Results show that normal subjects stood up quickly (mean, 1.67 sec; SD, .27 sec; range, 1.26 to 2.13 sec), and despite large amounts of trunk forward flexion and upward motion necessary to achieve the task of standing up, only small amounts of trunk rotation, trunk lateral flexion, and trunk lateral shift were measured during the activity. The identification of these movements characteristics may be beneficial in assisting with analysis of the STS movement pattern.