The effectiveness of 3 stretching techniques on hamstring flexibility using consistent stretching parameters

• Published in: Journal of strength and conditioning research Vol. 19; no. 1; pp. 27 - 32
• Main Authors: Davis, D Scott, Ashby, Paul E, McCale, Kristi L, McQuain, Jerry A, Wine, Jaime M
• Format: Journal Article
• Language: English
• Published: United States Lippincott Williams & Wilkins Ovid Technologies 01.02.2005
• Subjects: Adult; Female; Humans; Knee Joint - physiology; Male; Muscle, Skeletal - physiology; Pliability; Range of Motion, Articular - physiology; Space life sciences; Thigh; Time Factors
• ISSN: 1064-8011; 1533-4287
• DOI: 10.1519/14273.1

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.