title: Eccentric knee strength of elderly females.
abstract: This study compared the strength of the knee extension and flexion muscles in groups of young and elderly women under two conditions: eccentric exercise in which the muscles were lengthened while subjects tried to resist an external force, versus concentric contractions in which the muscles shortened. Twenty-six females, aged 20 to 29 (Mean 25 +/- 3 SD), and 26 elderly women, aged 66 to 89 (Mean 73 +/- 6 SD), were tested at two angular velocities of movement, 45 degrees and 90 degrees/s, on a KinCom isokinetic dynamometer. Elderly women had significantly lower peak and average torque values in all comparisons with the young female group (25 to 54% lower, p less than .01). However, differences between the age groups were consistently smaller for the eccentric type of muscle action than the concentric, in both knee extensors and flexors.
authors.affiliation: Department of Physical Therapy, University of Western Ontario.
authors.forename: A A
authors.initials: AA
authors.lastname: Vandervoort
authors.forename: J F
authors.initials: JF
authors.lastname: Kramer
authors.forename: E R
authors.initials: ER
authors.lastname: Wharram
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D009119:Muscle Contraction; D005082:Physical Exertion