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  • Author: Christina W.Y. Hui-Chan x
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William W.N. Tsang and Christina W.Y. Hui-Chan

Purpose:

To determine whether older golfers have better static and dynamic balance control than older but nongolfing healthy adults.

Methods:

Eleven golfers and 12 control participants (all male; 66.2 ± 6.8 and 71.3 ± 6.6 yr old, respectively) were recruited. Duration of static single-leg stance was timed. Control of body sway was assessed in single-leg stance during forward and backward platform perturbations. The lunge distance normalized with respect to each participant’s height was used to compare the 2 groups in a forward-lunge test.

Results:

Golfers maintained significantly longer duration in static single-leg stance. They achieved less anteroposterior body sway in perturbed single-leg stance and lunged significantly farther than did control participants.

Conclusions:

The better static and dynamic balance control exhibited by older golfers possibly reflects the effects of weight transfers from repeated golf swings during weight shift from 2-leg to predominantly 1-leg stance and from walking on uneven fairways.

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Rini Varghese, Christina W.Y. Hui-Chan and Tanvi Bhatt

This study quantified the effect of aging and the long-term practice of Tai Chi on upper limb movement control, indicated by performance outcome (temporal) and performance production (amplitude) measures, on a multiplanar stand-reaching (i.e., functional) task. Twelve Tai Chi practitioners (TCPs), 11 age-matched older nonpractitioners (ONPs), and 12 young subjects performed cued, flexion-reaching, and abduction-reaching tasks using a custom set-up. Surface EMG and acceleration data sampled from wireless sensors rendered performance outcome (reaction time, burst duration, time to peak, and movement time) and performance production (normalized EMG amplitude and peak acceleration) measures. Young subjects and TCPs demonstrated better performance outcome and performance production than ONPs. Relative-effect computations (i.e., the effect of Tai Chi expressed as a percentage of the effect of aging) showed that TCPs exhibited approximately 20–60% (flexion) and 20–100% (abduction) improvement in reaching task performance compared with ONPs. Tai Chi practitioners displayed better arm movement control than ONPs on a relatively challenging and functional stand-reaching task.

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Margaret K.Y. Mak, Oron Levin, Joseph Mizrahi and Christina W.Y. Hui-Chan

Calculation of joint torques during the rising phase of sit-to-stand motion is in most cases indeterminate, due to the unknown thighs/chair reaction forces in addition to the other sources of uncertainties such as joint positioning and anthropometric data. In the present study we tested the reliability of computation of the joint torques from a five-segment model; we used force plate data of thighs/chair and feet/ground reaction forces, in addition to kinematic measurements. While solving for joint torques before and after seat-off, differences between model solutions and measured data were calculated and minimized using an iterative algorithm for the reestimation of joint positioning and anthropometric properties. The above method was demonstrated for a group of six normal elderly persons.