Psychometrics of dominant right hand during the 9-hole PEG test: differences between PEG placement and removal

Objective: To assess psychometrics of hand dominance during the 9-Hole Peg Test.

Subjects: Sixteen healthy volunteers (23-40 years of age, 10 female and 6 male subjects, all fortuitously right handed).

Methods: As is conventional protocol, the total time to perform the task was recorded as a dexterity index. In addition, the relative distance between points (distal phalanges) on the index finger and thumb was continuously monitored by the use of a magnetic sensing system. Time required, mean values for peak distance, and cumulative total motion distance were analyzed separately for the peg-placement and peg-removal phases. Data for dominant and nondominant hands were compared by the use of paired t-tests (P < .05).

Results: Total time to perform the 9-Hole Peg Test was shorter for the dominant hands (mean, 18.65 seconds) than the nondominant hands (mean, 20.11 seconds). During the peg-placement phase, lower values for peak distance, cumulative total motion distance, and time required were recorded for dominant hands, suggesting more efficient movement. By contrast, during peg-removal phase, no statistically significant differences between dominant- and nondominant-hand values were apparent.

Conclusions: Although healthy subjects perform the 9-Hole Peg Test more efficiently using their dominant hands, the difference in measured dexterity was observed only during the peg-placement phase. This discrepancy between the peg-placement and peg-removal efficiency suggests the need for phase discrimination in future studies.