Date Presented 4/7/2016
What is the correlation between muscle strength of the upper extremity and hand function in older adults? Our study shows that arm-curl strength, rather than grip strength, is correlated with hand function. An arm-curl strength test may be used to predict hand function performance in older clients.
Primary Author and Speaker: Chiung-ju Liu
Additional Authors and Speakers: Aaron Frederick, Elaine Fess, Kristen Utley, Jessica Bertram, Deana Schuman
PURPOSE: The purpose of this research was to determine the correlation between muscle strength of the upper extremity (UE) and hand function in older adults. We hypothesized that higher grip strength as well as arm-curl strength are correlated with better hand function performance.
RATIONALE: Identifying modifiable factors related to late-life disability is important to promote productive aging. Numerous studies have shown that the decline in muscle strength of the lower extremity is strongly correlated with the limitation of functional mobility in older adults. Although grip strength is a good predictor for overall functional decline in older adults, studies describing the correlation between muscle strength of the UE and specific hand function in the older population are sparse.
DESIGN: We used a correlational research design.
PARTICIPANTS: Participants were eligible for the study if they were ≥60 yr old and English speaking. Participants were excluded if they had poor visual acuity or a neurological condition that affected motor movements. Participants were recruited from local senior congregate meal services sites or senior subsidized housing complexes.
METHOD: After informed consent was provided, each participant performed the seven subtests of the Jebsen–Taylor Test of Hand Function (writing, card turning, moving small common objects, simulated feeding, stacking checkers, moving light objects, and moving heavy objects), grip strength test (using Jamar hydraulic hand dynamometer), and 30-s arm-curl strength test in a common room at each recruitment site.
ANALYSIS: We conducted a series of Spearman’s rho correlational analyses using IBM SPSS Version 22.
RESULTS: Fifty participants (mean age = 72 yr) completed the study between August 2013 and October 2014. The correlation between grip strength and the Jebsen–Taylor Test of Hand Function is not significant (Spearman’s ρ = –.14, p = .34). However, the correlation between arm-curl strength and the Jebsen–Taylor Test of Hand Function approached significance (Spearman’s ρ = –.27, p = .07). Specifically, arm-curl strength was significantly correlated with the feeding (p = .02), stacking checkers (p = .05), moving light objects (p = .01), and moving heavy objects (p < .01) subtests.
DISCUSSION: The results suggest that arm-curl strength is more related to hand function than grip strength. Muscle strength contributing to gross motor movements of the UE may be a significant factor for hand function. Gross motor muscle strength provides mobility and stability of the upper arm to carry out daily tasks.
IMPACT STATEMENT: Grip strength has been used as an indicator for overall functional decline in older adults. However, this study suggests that grip strength is not correlated with hand function in the older adult population. Alternatively, arm-curl strength may be a better indicator for hand function. Occupational therapy practitioners could include the measure of arm-curl strength to predict hand function in older clients.
