Conditions Affecting Flexibility and Response to Stretching

Although much of the body s response to stretching is neural, several factors affect both one s flexibility and one s response to range of motion and stretching activities. You can modify some of these elements but not all. Factors you cannot change are age, presence of disease, previous injury to the muscle or joint, and scar tissue. You can, however, alter temperature and muscle imbalance, which influence a person s flexibility and response to stretching.

As tissue temperature rises, elasticity increases, and vice versa - as temperature drops, flexibility decreases. This change in flexibility can be as much as 20 percent of the original range of motion. This relationship explains why you feel stiffer when you are cold and why keeping your muscles warm while exercising in the cold is essential. It also suggests methods for improving one's flexibility and response to stretching activities. We can warm tissues by internal means, muscle contractions, or external means. External ways of increasing tissue temperature are as simple as covering the joint, applying heat packs, or taking a warm shower. One friend uses a neoprene sleeve for his knee when it is cold outside. He reports that not only does the sleeve keep the swelling down in his knee, but the warmth helps him feel looser and decreases the pain.

The strength of the muscles on either side of the joint, or in some cases adjacent to the joint, affects its range of motion. Around each joint opposing muscles create a sort of balance. If these muscles are sufficiently strong and flexible, they allow the joint to move through its entire range. However, if one set of muscles becomes weak compared to the opposing set, joint motion may be compromised. Poor posture and tight muscles can worsen such an imbalance.

For example, a common imbalance is one between the anterior and posterior shoulder muscles. Most of the time people perform tasks and lift objects in front of their bodies; as a result, the anterior muscles become stronger than the posterior ones. Habitually poor posture (such as hunching forward with rounded shoulders) exacerbates this condition. Poor posture combined with the muscle imbalance leads to tight pectoral muscles (although it is not really possible to say which of these problems comes first). Limited range of motion and shoulder pain are usually the consequences of these deficits. Although this chapter covers only flexibility, you can see how all of the components of fitness are interrelated.