title: Chronic flexibility gains: effect of isometric contraction duration during proprioceptive neuromuscular facilitation stretching techniques.
abstract: The aim of this study was to assess the effect of to isometic contraction durations during propiceptive neuromuscular facilitation stretching on gains inflexion at the hip. Forty-three women (M age = 20.0 years, SD = 1.3) were assigned to one of three groups: 5-s isometric contraction (5-IC), 10-IC, and control. Flexibility was assessed at baseline and Weeks 3 and 6. Analysis of covariance, controlling for pretest differences, showed a significant interaction, F(2, 33) = 44.1, p < .001. Flexibility was significant lower in the control group relative to the 5-IC and 10-IC groups and in the 5-IC group relative to the 10-IC group at 3 and 6 weeks (3 weeks = 101.2 +/- 1.4 degrees, 114.3 +/- 1.5 degrees, 120.5 +/- 1.3 degrees; 6 weeks = 103.0 +/- 1.4 degrees, 126.1 +/- 1.6 degrees, 133.3 +/- 1.4 degrees for control, 5-IC and 10-IC groups, respectively). A longer contraction time led to greater increases in flexibility.
authors.affiliation: School of Sport Health and Exercise Sciences, University of Wales-Bangor, UK. a.rowlands@bangor.ac.uk
authors.forename: Ann V
authors.initials: AV
authors.lastname: Rowlands
authors.forename: Vicky F
authors.initials: VF
authors.lastname: Marginson
authors.forename: Jonathan
authors.initials: J
authors.lastname: Lee
mesh_terms: D000328:Adult; D015444:Exercise; D005260:Female; D006621:Hip Joint / Q000502:physiology*; D006801:Humans; D007537:Isometric Contraction; D009126:Muscle Relaxation; D011434:Proprioception; D016059:Range of Motion, Articular; D013997:Time Factors