MAXIMAL VOLUNTARY ISOMETRIC FORCE PRODUCTION CHARACTERISTICS OF 6 MUSCLE GROUPS IN WOMEN AGED 25 TO 74 YEARS

The age-related force production characteristics of six muscle groups in 143 women aged 25-74 years were examined. Measures of maximal force (MFR) were obtained on the finger flexors (FF), thumb extensors (TE), forearm flexors (FAF), forearm extensors (FAE), dorsi flexors (DF), and plantar flexors (PF) utilizing a linear voltage differential transducer. The subjects were categorized by age into ten 5-year groups. The magnitude of decline across age in MFR ranged from 36.2% (FAE) to 45.1% (PF). There were differences among muscle groups in the age at which a significant decline in MFR was first detected. The earliest drop off in MFR was observed in FF and FAF (45-49 years), while the latest significant decline across age was noted in FAE (65-69 years). Since the magnitude of maximal force decreases with age, and because these characteristics can not be entirely explained by age-related decrements in fat-free mass, it appears that the quality in addition to the quantity of senescent muscle tissue may be compromised. However, the magnitude of decline in maximal force is dependent upon the muscle group considered.