This is an excerpt from Sports Injuries Guidebook-2nd Edition by Robert Gotlin.
By Jeff Young, Kinesiologist, CSCS, ACSM-EIM
Flexibility, the available range of motion (ROM) around each joint, and mobility, the amount of usable ROM in dynamic, loaded conditions, are important components of both movement and injury prevention (Page 2012, Witvrouw, Mahieu, and Danneels 2004). When restrictions exist because of lack of flexibility or mobility, movement is less efficient and the risk of injury increases. Many soft tissue injuries occur during the eccentric (lowering) phase of a movement while the muscles and tendons are under a load and on stretch (lengthening) (Verall and Dolman 2016). If a joint lacks flexibility, maximal or near-maximal lengthening of the muscles surrounding the joint will occur earlier in a movement. If this happens under a load, injury may occur. At a minimum, flexibility should be balanced around each major joint to reduce this risk (see figure 2.1).
To know objectively if a joint has restricted ROM, falls within the norms, or is hypermobile, an assessment should be performed at each major joint. It would behoove the athlete to have a joint ROM assessment performed by a qualified professional. Once this is accomplished, the athlete can be placed on a proper flexibility training program to balance flexibility around each major
Designing a flexibility program adheres to a principle known as FITT. The letters stand for Frequency, Intensity, Time (duration), and Type.