title: Effects of stretching on peak torque and the H:Q ratio.
abstract: The purpose of the present study was to examine the acute effects of hamstring and calf stretching on leg extension and flexion peak torque (PT) and the hamstrings-to-quadriceps (H : Q) ratio during maximal, concentric isokinetic muscle actions at 60, 180, and 300 degrees . s (-1) in women. Thirteen women (mean age +/- SD = 20.8 +/- 1.8 yrs; height = 163.0 +/- 5.7 cm; mass = 64.0 +/- 8.3 kg) performed 3 maximal concentric isokinetic leg extension and flexion muscle actions at 3 randomly ordered angular velocities (60, 180, and 300 degrees . s (-1)) before and after a bout of static stretching. The stretching protocol consisted of 1 unassisted and 3 assisted static stretching exercises designed to stretch the posterior muscles of the thigh and leg. Four repetitions of each stretch were held for 30 s with 20 s rest between repetitions. The results indicated that leg flexion PT decreased from pre- to post-stretching (34.9 +/- 3.5 and 32.4 +/- 3.2 Nm, respectively) collapsed across velocity. However, no other changes were observed from pre- to post-stretching for leg extension PT (78.5 +/- 5.9 and 77.8 +/- 5.5 Nm, respectively) and the H : Q ratio (0.47 +/- 0.04 and 0.44 +/- 0.03, respectively). Our findings suggested that despite the stretching-induced decreases in leg flexion PT, leg extension PT and the H : Q ratios were unaltered by the stretching.
authors.affiliation: Health and Exercise Science, University of Oklahoma, Norman, Oklahoma, United States.
authors.forename: P B
authors.initials: PB
authors.lastname: Costa
authors.forename: E D
authors.initials: ED
authors.lastname: Ryan
authors.forename: T J
authors.initials: TJ
authors.lastname: Herda
authors.forename: J M
authors.initials: JM
authors.lastname: DeFreitas
authors.forename: T W
authors.initials: TW
authors.lastname: Beck
authors.forename: J T
authors.initials: JT
authors.lastname: Cramer
mesh_terms: D005260:Female; D006801:Humans; D007866:Leg / Q000502:physiology; D009119:Muscle Contraction / Q000502:physiology*; D052580:Muscle Stretching Exercises / Q000379:methods*; D018482:Muscle, Skeletal / Q000502:physiology*; D019415:Torque; D055815:Young Adult