Time to peak torque for knee and elbow extensors and flexors in children, teenagers and adults

Abstract

The aim of this study was to examine the age and sex associated development of time to peak torque (TPT) of the knee and elbow extensors and flexors. 137 subjects participated in this study consisting of three groups aged 9/10 y, 16/17 y and 21+ y. Isokinetic concentric knee and elbow extension and flexion were measured using a calibrated Biodex system 3 and TPT was determined. ANOVA identified significant ( p< 0.05) interaction effects for stature and body mass. A main effect for group for knee extension TPT (range 0.20-0.26 s) and elbow flexion TPT (range 0.33-0.40 s) was identified. For elbow flexion the 16/17 y-olds demonstrated significantly faster TPT than the 9/10 y-olds and adults. No significant interaction or main effects for knee flexion (range 0.0.19-0.23 s) or elbow extension (range 0.40-0.44 s) were observed. Pearson product moment correlation coefficients identified no significant relationship between TPT and peak torque for knee and elbow extensors and knee flexors in all groups. A significant negative correlation ( p< 0.05) was found for the elbow flexors for both 9/10 y-olds and adults for females but not males. To conclude, no sex differences in TPT of the knee and elbow extensor and flexor muscles were found. Age related changes in TPT appear to be muscle group and muscle action specific and highlight the caution one has to exercise in making assumptions between muscle groups and actions.