The effect of an inclined landing surface on biomechanical variables during a jumping task
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Effect of stretching on strength loss and pain after eccentric exercise
by
McHugh MP, Nesse M.
—
last modified
2009-10-09 15:17
Med Sci Sports Exerc. 2008 Mar;40(3):566-73.
PURPOSE: The purposes of the this study were to determine whether stretch-induced
strength loss was muscle length dependent (study 1) and whether passive
stretching prior to eccentric exercise affected strength loss and pain on
subsequent days (study 2). METHODS: For study 1, knee flexion strength was
measured isometrically (six angles) and isokinetically (eccentric and concentric)
in 10 men (33 +/- 9 yr). The subjects then performed six 90-s static hamstring
stretches, after which isometric and isokinetic strength were retested. For study
2, the dominant and nondominant legs of eight men (34 +/- 9 yr) were assigned to
a stretch (six 60-s stretches) or control condition prior to eccentric hamstring
exercise. Isometric strength and pain were assessed prior to, immediately after,
and on the 3 d after exercise. RESULTS: After stretching, strength was decreased
by 17% at 80 degrees , 11% at 65 degrees , 5% at 50 degrees , 7% at 35 degrees ,
and 8% at 20 degrees , and it was increased by 6% at 5 degrees (angle effect P <
0.01). Strength loss following eccentric exercise was less on the stretched
versus the unstretched control limb at 37 degrees (P < 0.05), but not at other
angles (stretch by time by angle P < 0.01). Pain was not different between the
stretched and the unstretched control limb (P = 0.94). CONCLUSION:
Stretch-induced strength loss was dependent on muscle length, such that strength
was decreased with the muscle group in a shortened position, but not with the
muscle group in a lengthened position. Strength loss and pain after eccentric
exercise were generally unaffected by prior stretching, with the exception that
stretching prevented strength loss when assessed with the muscle in a lengthened
position.