The effects of circumferential wrist pressure on reproduction accuracy of wrist placement in healthy young and elderly adults.

BACKGROUND The purpose of this study was to determine the effect of circumferential wrist pressure on reproduction accuracy of wrist placement in healthy young and elderly adults. A convenience sample of 20 young adults having a mean age of 22.9 years and 20 elderly adults with a mean age of 68.2 years participated in the study. METHOD Blindfolded subjects were asked to actively self-select a neutral wrist position (reference) and then, when signaled, to actively reproduce the previously selected position. Wrist joint reproduction accuracy was assessed under four pressure conditions: no contact, wrist contact, 10 mm Hg, and 20 mm Hg. A single axis dynamic wrist electrogoniometer measured three dependent variables: absolute, constant, and variable errors. Data were analyzed by means of multivariate analysis of variance (MANOVA) for repeated measures. RESULTS No significant differences in reproduction accuracy under the four pressure conditions for young or elderly adults were found. CONCLUSIONS Healthy young and elderly adults may utilize existing intrinsic feedback and central control mechanisms to achieve accuracy during a reproduction task. Some subjects in both age groups who entered into the study with high error scores benefited from circumferential pressure by possibly relying on peripheral mechanisms. Further studies are needed to determine the effect of circumferential pressure on subjects with poor reproduction performance.