Relationship between grip strength and global muscle strength in community-dwelling older people

Abstract

There are still conflicting results regarding the association between grip and global muscle strength in older people. Therefore, the objective of the present study was to determine the association between grip strength and global muscle strength, as well as between grip strength and individual trunk, hip, knee and ankle muscle strengths.

Methods: Grip strength was assessed using a manual dynamometer, and trunk, hip, knee and ankle muscle strength with an isokinetic dynamometer, in order to obtain the global muscle strength variable, in 150 older men and women from the community. The association between grip and global muscle strength and between grip strength and the strength of each muscle group was determined through the Pearson correlation test, followed by multivariate linear regression adjusted for sex, age, body mass index, level of physical activity and number of comorbidities.

Results: A positive significant association was found between grip strength and global muscle strength in older people (r = 0.690; β = 10.07; p < 0.001; R² = 0.604), even after adjustment. There was also a low to moderate association between all the muscle groups and grip strength. However, when the model was adjusted, the relationship between grip strength and ankle dorsiflexor peak torque lost significance (p = 0.924).

Conclusion: Grip strength can represent global muscle strength in younger older people in the community, even when confounding variables are considered in the statistical model. However, grip strength does not eliminate the need for specific assessment of different muscle groups, when indicated.

Keywords: Aging; Ankle; Hip; Isometric peak torque; Knee; Trunk.