Flexibility is defined as the range of motion of a joint or series of joints that are influenced by muscles, tendons, ligaments, and bones. Flexibility is not a general measurement, but specific to each joint or group of joints. Flexibility is also specific to the joint being evaluated - one can be highly flexible in one joint and have limited range of motion in another. Flexibility is influenced by a number of factors. Females generally have greater flexibility than males.
Flexibility increases up to young adulthood and then decreases with age.
This is one of the many important reasons to continue our stretching exercises - to keep the flexibility of young adulthood so we can continue being active and not have to limit our activities. Temperature is also a factor with flexibility increasing with heat and decreasing with cold. Injury Prevention - muscles possessing greater extensibility are less likely to be overstretched during vigorous activity, lessening the likelihood of injury. Skill enhancement - Optimal flexibility aids athletic performance. Sufficient shoulder flexibility is necessary before the serve in tennis can be properly mastered.