Effect of age on voluntary force and cross-sectional area of human adductor pollicis muscle.

Muscle weakness accompanies ageing but its causes are still uncertain. We report maximum voluntary force measurements of adductor pollicis muscle, normalized for cross-sectional area, in twenty-three elderly subjects. Normalized force was lower in the elderly compared with a group of fifty-five young adult subjects by 27 +/- 4% (S.E.M.). This shows that atrophy alone is not the cause of the weakness of old age.