Resumen de Practicing a Functional Task Improves Steadiness with Hand Muscles in Older Adults

Adam R. Marmon, Jeffrey B. Gould, Roger M. Enoka

• Introduction: Improvements in steadiness with practice have been associated with enhanced performance on a functional task in old adults.

  Purpose: The aims of the study were to examine the specificity of the association between steadiness and a functional task and to assess the influence of practicing a functional task on force steadiness of hand muscles.

  Methods: Twenty-three older adults (=70 yr) participated in the study and were assigned to either a practice group (n = 15) or a control group (n = 8). Subjects completed two testing sessions that were 2 wk apart. The practice group completed six additional sessions to practice a functional task (Grooved Pegboard). Tests included maximal voluntary contractions (MVC), force steadiness (precision pinch and index finger abduction) at three target forces (5%, 15%, and 25% MVC), and the Grooved Pegboard test. The associations between strength, steadiness, and the time needed to complete the Grooved Pegboard test were examined. In addition, MVC force, steadiness, and pegboard time were compared between the two testing sessions.

  Results: The time needed to complete the Grooved Pegboard test was associated with index finger abduction steadiness for two of the three target forces (15% and 25% MVC) but was not associated with pinch steadiness. Practice significantly reduced the time needed to complete the Grooved Pegboard test and improved steadiness in both tasks.

  Conclusions: Force steadiness provides an appropriate index of hand function, especially when measured at low forces.