title: Validity of double- and single-leg vertical jumps as tests of leg extensor muscle function.
abstract: The purpose of this research was to determine if 5 weeks of resistance training for the shoulder and hip flexor muscles produces improvements in vertical jumping (VJ) performance. Twenty-eight men were assessed on tests of shoulder power, leg extensor muscle function, and VJ performance using jumps performed from a standing position, a 3-stride run-up, and double- and single-leg takeoffs. A shoulder and hip flexor training group (n = 14) improved significantly more than a nontraining control group (n = 12) in shoulder power and 2 VJ performance tests, but not in the tests of leg extensor muscle function. It was concluded that the arm swing and free-leg drive significantly influence VJ performance and, therefore, VJ tests are not valid for assessment of leg extensor muscle function.
authors.affiliation: School of Human Movement and Sport Sciences, University of Ballarat, Victoria, Australia.
authors.forename: W B
authors.initials: WB
authors.lastname: Young
authors.forename: C
authors.initials: C
authors.lastname: MacDonald
authors.forename: M A
authors.initials: MA
authors.lastname: Flowers
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D007839:Functional Laterality; D006615:Hip / Q000502:physiology; D006801:Humans; D007866:Leg / Q000502:physiology; D008297:Male; D009048:Motor Skills / Q000502:physiology; D009068:Movement / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology*; D010806:Physical Education and Training / Q000379:methods*; D012782:Shoulder / Q000502:physiology; D013177:Sports / Q000502:physiology*; D013178:Sports Medicine / Q000295:instrumentation*