title: The magnitude and rate of reduction in strength, dexterity and sensation in the human hand vary with ageing.
abstract: Cutaneous sensation and motor performance of the hand decline with age. It is not known if motor performance declines are influenced by reductions in cutaneous sensation, or if motor performance deteriorates at a consistent rate across motor tasks. Handgrip strength, finger-tapping frequency and grooved-pegboard performance were assessed for both hands of 70 subjects (20-88 years), 10 per decade. Motor declines were compared to reductions in perceptual cutaneous sensation tested at 10 hand sites using calibrated von Frey filaments. Motor performance decreased with age for all motor tasks (p<0.001). Handgrip strength (mean±SEM) decreased from 42.6±9.5 kg (in the 30s), to 23.7±7.6 kg (80s) or 44%; finger-tapping frequency from 6.4±0.8 Hz to 4.2±0.9 Hz, 34%; and grooved-pegboard (median [IQR]) increased from 59 s [57-66 s] to 111.5 s [101-125 s], 47%. The onset of the deterioration in motor performance varied with sex and task. Cutaneous sensation also decreased with age, measured as increased von Frey thresholds of 0.04 g [0.02-0.07] to 0.16 g [0.04-0.4] (p<0.001) between the 20s and the 80s, or 73%. Cutaneous sensation varied with sex, side-tested and site. Reductions in grip-based tasks were associated with sensory declines in the palm, but elsewhere there was little correlation among motor tasks and cutaneous sensation in the hand. Grooved-pegboard performance was the best predictor of age-related declines in motor performance regardless of sex or side-tested. Our results suggest age-related declines in motor function cannot be inferred from, or provide information about, changes in cutaneous sensation.
authors.affiliation: Neuroscience Research Australia, Barker Street, Sydney, NSW, Australia. j.bowden@neura.edu.au
authors.forename: Jocelyn L
authors.initials: JL
authors.lastname: Bowden
authors.forename: Penelope A
authors.initials: PA
authors.lastname: McNulty
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D006225:Hand / Q000502:physiology*; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D012677:Sensation / Q000502:physiology*; D012737:Sex Factors; D012879:Skin Physiological Phenomena; D013647:Task Performance and Analysis; D013997:Time Factors
keywords: Cutaneous sensation; Finger-tapping; Grooved-pegboard; Handgrip strength; Sensorimotor integration; Sex differences