Flexibility

Flexibility can be broken down into two main areas- muscle and joint flexibility.

Muscle flexibility is the ability of a muscle to stretch beyond its normal limits. By having flexible muscles we are much less likely to suffer from muscular strains and tears, which are serious injuries.
Joint flexibility is the range of movement a person has around their joints. Different joints have vastly differing ranges of motion. The shoulder for example is a very flexible joint, whereas the spinal joints are much less so.
Flexibility can be affected by injury and treatments, but can also be improved by stretching and specific exercises.