Effects of aging on hand function

OBJECTIVES: The purpose of this stud), was to quantify age-induced changes in handgrip and finger-pinch strength, ability to maintain a stead), submax imal finger pinch force and pinch posture, speed in relocating small object s with finger grip, and ability to discriminate two identical mechanical st imuli applied to the finger tip. DESIGN: A cross-sectional study. SETTINGS: Greater Cleveland area of Ohio. PARTICIPANTS: Healthy, independent, young (n = 27, range 20-35 years) and o lder (n = 28, range 65-79 years) subjects. MEASUREMENTS: Handgrip strength, maximum pinch force (MPF), ability to main tain a steady pinch force at three relative force levels (5%, 10%, and 20% MPF) and three absolute force levels (2.5 Newtons (N), 4 N, and 8 N), abili ty to maintain a precision pinch posture, speed in relocating pegs from a n earby location onto the pegboard, and the shortest distance for discriminat ing two stimuli were measured in both young and older groups. RESULTS: Compared,vith young subjects, the older group's handgrip force was 30% weaker (P < .001), MPF was 26% lower (P < .05), and ability to maintai n steady submaximal pinch force and a precision pinch posture was significa ntly less (P < .05). The time taken to relocate the pegs and the distance n eeded to discriminate two identical stimuli increased significantly with ag e (P < .01). The decrease in the ability to maintain steady submaximal pinc h force was more pronounced in women than men. CONCLUSION: Aging has a degenerative effect on hand function, including dec lines in hand and finger strength and ability to control submaximal pinch f orce and maintain a steady precision pinch posture, manual speed, and hand sensation.