Muscular overexertion may present as muscle soreness, muscle stiffness, and muscle spasm. According to the muscle spasm hypothesis of muscle soreness, ischemia to the muscles release pain substances from the muscle fibers and stimulate the pain receptors, resulting in reflex spastic contractions and a continued cycle of ischemia and pain, Stretching the muscles helps reduce the spasms and associated pain. According it) the tissue damage hypothesis, micro-tears occur and pain/soreness results from the nerve - endings being stimulated by muscle tissue swelling. Proper massage aid in reducing tissue edema, and decreasing accompanying muscle spasm. Ice applications or other forms of cryotherapy, and pool training, may facilitate the body's healing response. Appropriate rest will allow microscopic damage of the tissue to heal.
Active range of motion, also called dynamic flexibility, refers to the degree to which a joint can be moved by a muscle contraction, usually through the mid-range of movement. Dynamic flexibility is not necessarily a good indicator of the stiffness or looseness of a joint because it applies to the ability to move a joint efficiently, with little resistance to motion.
Passive range of motion, sometimes called static flexibility, refers to the degree to which a joint may be passively moved to the endpoints in the range of motion. No muscle contraction is involved to move a joint through a passive range.
When a muscle actively contracts, it produces a joint movement through a specific range of motion. However, if passive pressure is applied to an extremity, it is capable of moving farther in the range of motion. It is essential in sport activities that an extremity is capable of moving through a non-restricted range of motion. For example, a hurdler who cannot fully extend the knee joint in a normal stride is at considerable disadvantage because stride length and thus speed will be reduced significantly.
Passive range of motion is important for injury prevention. There are many situations in sport in which a muscle is forced to stretch beyond its normal active limits. If the muscle does not have enough elasticity to compensate for this additional stretch, it is likely that the musculotendinous unit will be injured.
