Measuring methods for functional reach test: comparison of 1-arm reach and 2-arm reach.

UNLABELLED

Kage H, Okuda M, Nakamura I, Kunitsugu I, Sugiyama S, Hobara T. Measuring methods for functional reach test: comparison of 1-arm reach and 2-arm reach.

OBJECTIVES

To investigate which functional reach test better reflects the center of pressure excursion, a 1-arm reach or a 2-arm reach, and to investigate the effect of trunk rotation on the reach distance in a 1-arm reach. In addition, we considered the influence of the individual variation at the starting position.

DESIGN

Descriptive study using a force platform and a 3-dimensional (3D) motion capture system.

SETTING

Motion analysis laboratory in a college setting.

PARTICIPANTS

Elderly volunteers (N=41; 15 men, 26 women; 71.8+/-5.2y).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

3D coordinate data and the movement of the center of pressure.

RESULTS

The correlation between the reach distance and the center of pressure excursion was significantly higher (P<.05) for the 1-arm reach (r=.60, .72) compared with a 2-arm reach (r=.41, .55). In the case of the 1-arm reach, center of pressure excursion was a significant factor affecting reach distance (beta=.319, .470) in multivariate regression analysis, but trunk rotation was not (beta=.162, .095). When the reach distance was measured using the heel as a reference, the correlation was stronger.

CONCLUSIONS

To evaluate dynamic balance, a 1-arm reach, which better reflects center of pressure excursion, is more valid. It is meaningful to reduce the individual variation of the acromion at the starting position.