title: Muscle strength and contractile kinetics of isometric elbow flexion in girls and women.
abstract: Ten prepubertal girls and 15 young women were tested for maximal torque, peak rate of torque development, electro-mechanical delay (EMD), and time to peak rate of torque development during isometric elbow flexion. Absolute peak torque (17.0 +/- 7.7 vs. 40.5 +/- 8.3 Nm) and peak rate of torque development (105.9 +/- 58.6 vs. 297.2 +/- 113.0 Nm s(-1)) were lower in the girls (p < .05). Normalized to muscle cross sectional area, torque was similar (8.27 +/- 2.74 vs. 8.44 +/- 1.65 Nm cm(-2)), as was peak rate of torque development, normalized to peak torque (6.21 +/- 1.94 vs. 7.30 +/- 2.26 Nm s(-1)/ Nm). Both, time to peak rate of torque development (123.8 +/- 36.0 vs. 110.5 +/- 52.6 ms) and EMD (73.2 +/- 28.6 vs. 51.9 +/- 25.6 ms), were longer in the girls, although EMD's difference only approached statistical significance (p = .06). Age-related isometric strength differences in females appear to be mainly muscle-size dependent. However, the time to peak torque and EMD findings suggest differential motor-unit activation which may functionally manifest itself in fast dynamic contractions.
authors.affiliation: Department of Physical Education and Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, Ontario, Canada.
authors.forename: Bareket
authors.initials: B
authors.lastname: Falk
authors.forename: Laura
authors.initials: L
authors.lastname: Brunton
authors.forename: Raffy
authors.initials: R
authors.lastname: Dotan
authors.forename: Charlotte
authors.initials: C
authors.lastname: Usselman
authors.forename: Panagiota
authors.initials: P
authors.lastname: Klentrou
authors.forename: Davie
authors.initials: D
authors.lastname: Gabriel
mesh_terms: D000375:Aging; D001132:Arm / Q000502:physiology*; D002648:Child; D004576:Electromyography; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D053580:Muscle Strength; D055815:Young Adult