title: The effectiveness of 3 stretching techniques on hamstring flexibility using consistent stretching parameters.
abstract: This study compares the effects of 3 common stretching techniques on the length of the hamstring muscle group during a 4-week training program. Subjects were 19 young adults between the ages of 21 and 35. The criterion for subject inclusion was tight hamstrings as defined by a knee extension angle greater than 20 degrees while supine with the hip flexed 90 degrees . The participants were randomly assigned to 1 of 4 groups. Group 1 (n = 5) was self-stretching, group 2 (n = 5) was static stretching, group 3 (n = 5) was proprioceptive neuromuscular facilitation incorporating the theory of reciprocal inhibition (PNF-R), and group 4 (n = 4) was control. Each group received the same stretching dose of a single 30-second stretch 3 days per week for 4 weeks. Knee extension angle was measured before the start of the stretching program, at 2 weeks, and at 4 weeks. Statistical analysis (p < or = 0.05) revealed a significant interaction of stretching technique and duration of stretch. Post hoc analysis showed that all 3 stretching techniques increase hamstring length from the baseline value during a 4-week training program; however, only group 2 (static stretching) was found to be significantly greater than the control at 4 weeks. These data indicate that static stretching 1 repetition for 30 seconds 3 days per week increased hamstring length in young healthy subjects. These data also suggest that active self-stretching and PNF-R stretching 1 repetition for 30 seconds 3 days per week is not sufficient to significantly increase hamstring length in this population.
authors.affiliation: Department of Human Performance and Exercise Science, Division of Physical Therapy, West Virginia University, Morgantown, West Virginia 26505, USA. dsdavis@hsc,wvu.edu
authors.forename: D Scott
authors.initials: DS
authors.lastname: Davis
authors.forename: Paul E
authors.initials: PE
authors.lastname: Ashby
authors.forename: Kristi L
authors.initials: KL
authors.lastname: McCale
authors.forename: Jerry A
authors.initials: JA
authors.lastname: McQuain
authors.forename: Jaime M
authors.initials: JM
authors.lastname: Wine
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D018583:Pliability; D016059:Range of Motion, Articular / Q000502:physiology*; D013848:Thigh; D013997:Time Factors