Reliability and validity of the sequential weight-shifting test: a new functional approach to the assessment of the sitting balance of older adults.

[Purpose] The evaluation of sitting balance is important for the prevention of falls in older adults, especially those who have a disability involving the lower extremities. However, no studies have been designed to assess a patient's dynamic sitting balance using a sequential protocol. The objective of this study was to investigate the psychometric properties of the sequential weight-shifting (SWS) test. [Subjects and Methods] Twenty-three older adults who were physically dependent with regard to ambulation were recruited by convenience sampling. In study 1, 10 participants performed the SWS test and repeated the procedure 1 week later. In study 2, 23 participants were assessed using the SWS test, forward and lateral reach tests in a sitting position, tests of shoulder flexor and hand grip strength, an eye-hand coordination test, mobility tests, and pulmonary function tests. The test-retest reliability of the SWS test and its correlations with the different physical dimensions were examined. [Results] The intraclass correlation coefficient (3,1) of the SWS test was 0.67. The results of the SWS test correlated significantly with forward reach in the sitting position, arm muscle strength, eye-hand coordination, mobility, and pulmonary function (all p<0.05). [Conclusion] The SWS test demonstrated satisfactory psychometric properties and can be considered a useful functional approach for the measurement of sitting balance.

The effects of practicing sitting Tai Chi on balance control and eye-hand coordination in the older adults: a randomized controlled trial.

PURPOSE: The purpose of this study was to examine the effects of 3 months of sitting Tai Chi training on the sitting balance control and eye-hand coordination of older adults subjects. METHODS: We randomly assigned 59 older adults from four residential care facilities to either sitting Tai Chi group or mobilizing exercises group as control. The sitting Tai Chi group underwent 3 months of training with a total of 36 sessions (1 hour/session, 3 sessions/week). The outcome measures included sitting balance tests (testing sequential weight shifting and forward reaching in a sitting position) and eye-hand coordination tests (reaction time, movement time and accuracy in finger pointing task). RESULTS: The Tai Chi practitioners showed significant improvement in their sequential weight shifting while sitting (improved by 29.0%, p ≤ 0.05) and in their maximum reaching distance from a sitting position (improved by 21.2%, p ≤ 0.05). No such improvements were found in the control group. In the eye-hand coordination test, the sitting Tai Chi practitioners had significant improvements in accuracy (improved by 17.3%, p ≤ 0.05). Also, no improvement was found in the control group. CONCLUSIONS: The results demonstrate 3-months of sitting Tai Chi training can improve sitting balance and accuracy in finger pointing task in the older adults. IMPLICATIONS FOR REHABILITATION: Traditional Tai Chi poses difficulties for older adults with poor standing balance. This pilot study showed that a 3 months sitting Tai Chi training can improve sitting balance and accuracy in the finger pointing task in the older adults. Sitting Tai Chi can be a therapy option for older adults with poor standing balance.

Effects of concurrent cognitive task on pre-landing muscle response latency during stepping down activity in older adults with and without a history of falls.

PURPOSE: To investigate the co-contraction of ankle muscles in older subjects with and without a history of falls during a stepping down activity, and whether the co-contraction was disrupted by a concurrent cognitive task. METHOD: Ten fallers and 9 non-fallers (mean age = 72.0 +/- 5.0 and 72.1 +/- 7.3 years, respectively) were recruited. Electromyography (EMG) of the tibialis anterior (TA) and medial gastrocnemius (MG) was recorded during stepping down with and without a concurrent cognitive task. Co-contraction was investigated using the time between the EMG onset and the foot touching a force-platform, termed the pre-landing muscle response latency. RESULTS: The fallers showed longer pre-landing muscle response latencies in the TA compared with non-fallers (141.1 +/- 58.1 ms and 110.9 +/- 68.2 ms, respectively). With a concurrent cognitive task, the pre-landing muscle response latencies in the TA were shortened in fallers significantly more than in non-fallers (44.4% and 15.5%, respectively). No significant difference in MG activation was found between 2 groups in the stepping down activity with and without cognitive task. CONCLUSIONS: Subjects with history of falls exhibit a greater shortening in the pre-landing muscle response latency than non-fallers when distracted during stepping down. Disruption of their co-contraction in ankle joint might precipitate such older adults to fall.