Background: How the natural deterioration of aging, sex difference, and pathological effect of stroke affect the prediction of hand strength is still unknown.
Aim: This study aimed to compare and predict grip strength in both hands between normal controls (NCs) and stroke patients.
Design: Observational, cross-sectional study.
Setting: Two urban hospitals and the community.
Population: A total of 160 participants aged from 40 to 80 (80 NCs and stroke patients) were recruited.
Methods: The Jamar® Plus+ Digital Hand Dynamometer was used to measure the grip strength. Stroke participants were additionally assessed by the Fugl-Meyer Assessment and Modified Ashworth Scale.
Results: The linear regression models of the grip strength in both right and left hands were good fits (the adjusted R2 of 0.680-0.751) between NCs and stroke patients with either the right dominant or left non-dominant hand affected. Group (NCs versus stroke), sex, and age were sequentially the first three statistically significant predictors in the grip strength of both hands between NCs and stroke patients with either the right dominant or left non-dominant hand affected.
Conclusions: The pathological, sex, and age effects play complementary roles in predicting the grip strength in middle-aged and older adults between NCs and stroke patients.
Clinical rehabilitation impact: In clinical practice, the recovery of the grip strength in stroke patients should take pathological, sex, and age effects together with the right dominant or left non-dominant hand affected into consideration, rather than merely comparing the differences in the grip strength of both right and left hands as a reference.