Effect of laterality on the contractile properties of human leg and hand muscles

Abstract

The effects of laterality on the electrically evoked mechanical properties of the first dorsal interosseus muscle of the hand and the triceps surae of the lower leg have been measured in 21 healthy male subjects. The results show that the time to peak tension (TPT) and half relaxation time (½RT) of the maximal twitch response were not significantly (p>0.1) different in the dominant and non-dominant triceps surae muscle, but the TPT of the first dorsal interosseus muscle was 7 ms (p < 0.05) longer in the non-preferred hand. The TPT of the two muscle groups was associated with fatiguability. The triceps surae (TPT 120-124 ms) lost ∼ 30% less force than the first dorsal interosseus (TPT 67-73 ms) when subjected to a standard 2min fatigue test, but there was no effect of dominance on fatiguability, nor on the electrically evoked maximal twitch and 40 Hz tetanic tension of the two muscle groups measured. However, the lorce of maximal voluntary contraction (MVC) was 255 N (p<0.01) less in the triceps surae of the non-dominant leg. It is concluded that.the use of a single limb for studying changes of muscle function (with control measurements taken on the contralateral limb) in intervention studies is valid, provided results are based on electrically evoked contractions.

Keywords:

• Muscle
• Dominance
• Electrically evoked contractions
• MVC
• Isometric exercise

Additional information

Notes on contributors

M. TANAKA

Present address: Department of Hygiene, School of Medicine, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142, Japan.