Garrick and Webb1 in their excellent book, Sports Injuries: Diagnosis and Management, state that a weak muscle is a tight muscle. This concept is extremely important when we think of the causes and rehabilitation of muscle or musculotendinous strains.
Muscle injuries are more often likely to happen during eccentric contraction. When eccentric contraction occurs, a muscle resists its own lengthening while the joint angle increases during the contraction. During maximum effort two times more muscle force is generated during eccentric over concentric contraction. Hamstring strains are likely to occur during the late forward swing phase (eccentric) when the hamstrings are decelerating thigh flexion and knee extension. A tear may result due to a difference in coordination between the contracting hamstrings and relaxing quadriceps.2 A tear may also result when the hamstrings switch from mid-support phase (knee stabilization) to hip extension and knee flexion at toe-off.
Reinjury of hamstring injuries is common in sports. Failure to reestablish hamstring strength and failure to use friction massage until the fibrotic deposits are eliminated are definite reasons for recidivism.
- Garrick, J.G.; Webb, D.R. Sports Injuries: Diagnosis and Management. Philadelphia, W.B. Saunders 1990; pp 7-25.
- Klafs, C.E.; Arnheim, D.D. Modern Principles of Athletic Training. 4th ed. Baltimore, Williams and Wilkins 1971.
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