Introduction
Stretching prior to participation in sports activities is standard protocol for all levels of sports, comp etitive or recreational.[l] Stretching is traditionally used as part of a warm-up to increase flexibility or pain-free range of motion (ROM) about a joint in an attempt to promote better performances and/ or reduce the risk of injury.[2] Rehearsal of the skill about to be performed is incorporated into the warm-up regime at incremental intensities so that the specific muscle fibers and neural pathways are recruited for optimum performance.[3]
Physiotherapist also recommend that their athletes or patients stretch before performing
strengthening exercises or strength assessment tests. However, authors of recent systematic reviews have suggested that pre-exercise stretching may temporarily compromise a muscle's ability to produce force and power output. It may be possible that this short-term effect of stretching on muscle force and power production may have negative effect on performance of various reh abilita tion exercises.[2]
This stretching-induced force deficit'' has been reported to affect isometric force , Power, concentric isokinetic peak torque , dynamic constant external resistance (DCER) force , vertical jumping performance and balance.[4]
Two main assumptions have been put forward to rationalize the stretching-induced force deficit: (a) mechanical factors, such as decrement in musculotendinous stiffness that may affect the muscle's length - tension relationship and/or sarcomere shortening velocity and (b) neural factors, that may reduce peripheral muscle activation, reduced muscle firing frequency, and/or altered reflex