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Effects of contract‐relax vs static stretching on stretch‐induced strength loss and length–tension relationship
Author(s) -
Balle S. S.,
Magnusson S. P.,
McHugh M. P.
Publication year - 2015
Publication title -
scandinavian journal of medicine and science in sports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.575
H-Index - 115
eISSN - 1600-0838
pISSN - 0905-7188
DOI - 10.1111/sms.12399
Subject(s) - isometric exercise , static stretching , hamstring , tension (geology) , muscle strength , ultimate tensile strength , medicine , materials science , chemistry , range of motion , surgery , composite material
The purpose of this study was to determine the acute effects of contract‐relax stretching ( CRS ) vs static stretching ( SS ) on strength loss and the length‐tension relationship. We hypothesized that there would be a greater muscle length‐specific effect of CRS vs SS . Isometric hamstring strength was measured in 20 healthy people at four knee joint angles (90°, 70°, 50°, 30°) before and after stretching. One leg received SS , the contralateral received CRS . Both stretching techniques resulted in significant strength loss, which was most apparent at short muscle lengths [ SS : P = 0.025; stretching × angle P < 0.001; 11.7% at 90° P < 0.01; 5.6% at 70° nonsignificant (ns); 1.3% at 50° ns; −3.7% at 30° ns. CRS : P < 0.001; stretching × angle P < 0.001; 17.7% at 90°, 13.4% at 70°, 11.4% at 50°, all P < 0.01, 4.3% at 30° ns]. The overall stretch‐induced strength loss was greater ( P = 0.015) after CRS (11.7%) vs SS (3.7%). The muscle length effect on strength loss was not different between CRS and SS (stretching × angle × stretching technique P = 0.43). Contrary to the hypothesis, CRS did not result in a greater shift in the length–tension relationship, and in fact, resulted in greater overall strength loss compared with SS . These results support the use of SS for stretching the hamstrings.