Age-independent Decline in Manual Dexterity of Middle-aged and Older Adults

Age-independent Decline in Manual Dexterity of Middle-aged and Older Adults

The objective of the clinical trial is to evaluate the mediating influence of force control on the pegboard times of adults (50-89 years) who are stratified into groups of faster and slower pegboard times. The hypothesis is that practice of either a pegboard test or a force-control task will reduce pegboard times, but the decrease will be greater and less similar after the two practice interventions for the slower group of participants. The outcomes are expected to demonstrate that force control is a modifiable mediator of pegboard times for this cohort, but the effect will be stronger for the group with faster pegboard times.

The study will involve a randomized, cross-over design with a one-week washout between arms. The two arms (3 weeks each) will comprise practice of the grooved pegboard test and practice of steady contractions while lifting and lowering light loads with a hand muscle. Randomization into practice order will be accomplished with a block approach (block size = 4) for each of the two groups. The outcome assessors will be blinded to practice order. The outcomes will comprise three tests of manual dexterity and the measurement of force control during submaximal contractions. The outcomes will be obtained before and after the six sessions in each practice arm.

Inclusion Criteria:

• Able to read, write, and speak English
• Able to arrange transportation to the Boulder campus

Exclusion Criteria:

• Cognitive impairment
• Major psychiatric condition
• Unstable depressive disorder
• Progressive neurological, muscular, cardiovascular, or skeletal disorder
• Chronic pain condition
• Currently taking medication known to influence neuromuscular function
• Recent hospitalization
• Unable to attend 12 practice sessions in 6 weeks