Isokinetic neck muscle strength-ratios in sagittal and frontal planes: Men and women are different, but age differences are a myth

Abstract

Strengthening of neck muscles has therapeutic value, but should be done with due cognisance of agonist/antagonist strength ratios. Limited information regarding dynamic neck strength ratios is known to guide rehabilitation. The purpose of the current research was to delineate and compare isokinetic strength-ratio data for flexion/extension and lateral flexion to the non-dominant/dominant side of the neck stratified according to gender and age. Healthy males (n=221) and females (n=231) aged 19 to 69 years were assessed and strength ratios and 95% confidence intervals were calculated. Strength ratios were analysed using ANOVA analysis with Scheffè post hoc tests, to determine whether significant differences existed between gender and age categories. Males had a significantly larger (p<0.05) flexion/extension strength ratio than the females (males= 0.63±0.14; females= 0.56±0.16). No significant difference was observed between males (1.03±0.11) and females (1.03±0.12) for lateral flexion strength ratio. No significant differences in strength ratios were observed between age categories within each gender. Isokinetic strength ratios of gender-discriminant age categories presented contribute to the delineation of dynamic neck muscle function. The use of gender-specific isokinetic strength ratios is warranted, but not age specific ratios.

Key words: Neck muscles; Muscle strength; Rehabilitation.