Menopause alters temperature sensitivity of muscle force in humans

Isometric maximum voluntary force (MVF) of the adductor pollicis and first dorsal interosseous muscles was measured in 11 pre- and 11 post-menopausal (Pre-M and Post-M) human subjects. The temperature of the hand varied in the range 18°-38°C by water immersion and skin temperature was recorded. MVF at each temperature was expressed relative to the value at skin temperature above 35°C to give MVF(REL). The form of the relation between MVF(REL) and temperature was different in the Pre-M and Post-M groups (p < 0.01). In the Pre-M group the maximum value of MVF(REL) occurred near 30°C and force fell at both higher and lower temperatures. In the Post-M group MVF(REL) showed an approximately linear decline with cooling across the whole temperature range. The maximum value of MVF(REL) for the Post-M group was near 35°C. The values of MVF(REL) for the Post-M group were significantly lower than for the Pre-M group at temperatures between 18° and 30°C.