title: Viscoelastic stress relaxation in the hamstrings before and after a 10-week stretching program.
abstract: BACKGROUND
  We investigated the viscoelastic stress relaxation response before and after a 10-week hamstrings static stretch program.
  
  
  METHODS
  The maximal range of motion (ROMmax ) and maximal torque (Torquemax ) were assessed before and after a 10-week stretching program. Six 30-s static stretches at a predetermined torque were performed, and the relative change in stress relaxation was examined.
  
  
  RESULTS
  ROMmax and Torquemax increased by 53% and 82%, respectively (P < 0.001). The relative stress relaxation (RSR) decreased significantly for repetition 1 when comparing the pretest (25%) and posttest (21%) values (P = 0.003). A significant decrease was also observed for repetitions 2 and 3 (P < 0.014), with no significant difference in repetitions 4-6 (P > 0.056).
  
  
  CONCLUSIONS
  Individuals who participated in a 10-week hamstrings passive-static stretch program had a reduced RSR response. A higher stretch intensity or longer duration may be necessary to achieve RSRs similar to those reported before the stretch program.
authors: Laboratory of Biomechanics, Center of Sports Excellence, Federal University of Minas Gerais, Avenida Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, Minas Gerais, 31270-901, Brazil.
authors: Gustavo H
authors: GH
authors: Peixoto
authors: Andre G
authors: AG
authors: Andrade
authors: Hans J K
authors: HJ
authors: Menzel
authors: Silvia R S
authors: SR
authors: Araújo
authors: Antônio E M
authors: AE
authors: Pertence
authors: Mauro H
authors: MH
authors: Chagas
mesh_terms: D004548:Elasticity / Q000502:physiology*; D006801:Humans; D008297:Male; D009126:Muscle Relaxation / Q000502:physiology*; D052580:Muscle Stretching Exercises / Q000379:methods*; D018482:Muscle, Skeletal / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology; D013312:Stress, Physiological / Q000502:physiology*; D013710:Tendons / Q000502:physiology; D019415:Torque; D016896:Treatment Outcome; D055815:Young Adult
keywords: flexibility; hamstrings; passive torque; stress relaxation; stretch