Reproducibility of dynamometers in handrail format in evaluating handgrip strength and traction in young and older adults

Background: The aim of the present study was twofold: (1) to assess the reproducibility of two dynamometers in handrail format to measure handgrip strength and traction force in the young and older adults; (2) to compare the handgrip strength and traction of these two populations.

Approach: Twenty-four volunteers (12 older adults and 12 young adults) performed a functional effort related to handgrip strength and traction force during stair climbing. The participants were evaluated two times (separated by one week) using a coupled dynamometer that quantifies the muscular effort in grip and traction simultaneously to simulate stair climbing in bus service.

Results: The young adults performed significantly better (p < 0.04) than the older adults in both handgrip and traction efforts (medium to large effect size), with excellent reliability (Intraclass Coefficient Correlation > 0.9) and low error of measure. The dynamometers were able to discriminate the two population groups (sensitive validity) and showed excellent reproducibility estimates for handgrip and traction strength in both young and older adults.

Conclusion: These instruments could be useful in assessing handgrip and traction strength needed to climb stairs, especially for the older adults, who normally have more difficulty performing this task.