title: The effects of passive stretching plus vibration on strength and activation of the plantar flexors.
abstract: This study examined the effects of passive stretching only (PS+CON) and passive stretching with the addition of continuous vibration (VIB) during post-passive stretching tests (PS+VIB) on peak torque (PT), percent voluntary inactivation (%VI), single stimulus twitch torque (TTSINGLE), and doublet stimuli twitch torque (TTDOUBLET) of the plantar flexors at a short (20° plantar flexion (PF)) and long muscle length (15° dorsiflexion (DF)). Fourteen healthy men (age = 22 ± 3 years) performed isometric maximal voluntary contractions at PF and DF, and passive range of motion (PROM) assessments before and after 8 × 30-s passive stretches without (PS+CON) or with VIB (PS+VIB) administered continuously throughout post-passive stretching tests. The passive properties of the muscle tendon unit were assessed pre- and post-passive stretching via PROM, passive torque (PASSTQ), and musculotendinous stiffness (MTS) measurements. PT, TTSINGLE, and TTDOUBLET decreased, whereas, %VI increased following passive stretching at PF and DF (P < 0.05) with no significant differences between PS+CON and PS+VIB. PASSTQ and MTS decreased while PROM increased post-passive stretching during both trials (P < 0.05). The stretching-induced force/torque deficit and increases in %VI were evident following passive stretching at short and long muscle lengths. Although not statistically significant, effect size calculations suggested large and moderate differences in the absolute changes in PT (Cohen's d = 1.14) and %VI (Cohen's d = 0.54) from pre- to post-passive stretching between treatments, with PS+VIB having greater decreases of PT and higher %VI than PS+CON. The decrement in PT following passive stretching may be primarily neural in origin.
authors: Neuromechanics Laboratory, Department of Health, Sport and Exercise Sciences, University of Kansas, Lawrence, KS 66044, USA.|Neuromechanics Laboratory, Department of Health, Sport and Exercise Sciences, University of Kansas, Lawrence, KS 66044, USA.
authors: Jonathan D
authors: JD
authors: Miller
authors: Neuromechanics Laboratory, Department of Health, Sport and Exercise Sciences, University of Kansas, Lawrence, KS 66044, USA.|Neuromechanics Laboratory, Department of Health, Sport and Exercise Sciences, University of Kansas, Lawrence, KS 66044, USA.
authors: Trent J
authors: TJ
authors: Herda
authors: Neuromechanics Laboratory, Department of Health, Sport and Exercise Sciences, University of Kansas, Lawrence, KS 66044, USA.|Neuromechanics Laboratory, Department of Health, Sport and Exercise Sciences, University of Kansas, Lawrence, KS 66044, USA.
authors: Michael A
authors: MA
authors: Trevino
authors: Neuromechanics Laboratory, Department of Health, Sport and Exercise Sciences, University of Kansas, Lawrence, KS 66044, USA.|Neuromechanics Laboratory, Department of Health, Sport and Exercise Sciences, University of Kansas, Lawrence, KS 66044, USA.
authors: Eric M
authors: EM
authors: Mosier
mesh_terms: D000125:Achilles Tendon / Q000502:physiology* / Q000503:physiopathology; D000328:Adult; D019054:Evoked Potentials, Motor; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D053580:Muscle Strength; D052580:Muscle Stretching Exercises / Q000009:adverse effects*; D018908:Muscle Weakness / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D018482:Muscle, Skeletal / Q000502:physiology* / Q000503:physiopathology; D000069262:Plantar Plate; D016059:Range of Motion, Articular; D012720:Severity of Illness Index; D019415:Torque; D004561:Transcutaneous Electric Nerve Stimulation; D014732:Vibration / Q000627:therapeutic use*; D055815:Young Adult
keywords: amplitude de mouvement passif; fléchisseurs plantaires; interpolated twitch; passive range of motion; passive stretching; plantar flexors; secousse interpolée; vibration; étirement passif