Strength Training Improves the Tri-Digit Finger-Pinch Force Control of Older Adults

Keogh JW, Morrison S, Barrett R. Strength training improves the tri-digit finger-pinch force control of older adults.ObjectiveTo investigate the effect of unilateral upper-limb strength training on the finger-pinch force control of older men.DesignPretest and post-test 6-week intervention study.SettingExercise science research laboratory.ParticipantsEleven neurologically fit older men (age range, 70–80y).InterventionThe strength training group (n=7) trained twice a week for 6 weeks, performing dumbbell bicep curls, wrist flexions, and wrists extensions, while the control group subjects (n=4) maintained their normal activities.Main Outcome MeasuresChanges in force variability, targeting error, peak power frequency, proportional power, sample entropy, digit force sharing, and coupling relations were assessed during a series of finger-pinch tasks. These tasks involved maintaining a constant or sinusoidal force output at 20% and 40% of each subject’s maximum voluntary contraction. All participants performed the finger-pinch tasks with both the preferred and nonpreferred limbs.ResultsAnalysis of covariance for between-group change scores indicated that the strength training group (trained limb) experienced significantly greater reductions in finger-pinch force variability and targeting error, as well as significantly greater increases in finger-pinch force, sample entropy, bicep curl, and wrist flexion strength than did the control group.ConclusionsA nonspecific upper-limb strength-training program may improve the finger-pinch force control of older men.