Sometimes when people discuss how they move, they will use different words interchangeably, not realizing that there are stark differences between them.
Two of these words are flexibility and mobility, and while they share some common properties, the way you go about improving them and the effect they have on your body is different.
Let’s start with flexibility, which is generally defined as the ability of a joint and its surrounding tissues to allow a stretch or movement in a single direction, usually measured in terms of an angle or range-of-motion. Factors affecting flexibility include age, genetics, physical activity and injury.
Two common factors that tend to reduce flexibility are muscle contraction from exercise and muscle shortening due to posture. When we move (run, walk, play sports, lift weights), we contract and shorten our muscles, and this creates movement. This tends to shorten muscle length and reduce flexibility, unless we make an effort to do stretching exercises to improve our flexibility.
But muscles can become shorter often with people who have static work postures like sitting. Long periods of sitting will generally cause a chronic shortening of the hamstrings (back of the thigh), hip flexors (front of the hips), and often the chest and posterior neck, especially when sitting at a computer station.
The problem with having shortened muscles is that this may increase the risk for injury, reduce performance in sport and is generally associated with muscle discomfort or pain when at rest, It can also cause muscle imbalances around a joint, further diminishing optimal function.
We can counteract these deleterious effects of inflexibility by doing stretching exercises.
Mobility, on the other hand, is usually defined as the ability of a joint to move through its range of motion in all the different angles and planes of movement.
If there are restrictions in the capsule that surrounds a joint or joint alignment problems, a physical therapist may use manual techniques to increase the mobility in a joint that is ‘hypo-mobile’ (restricted mobility).
Recently, strength and conditioning coaches and sports therapists have broadened the definition of mobility to include the notion that it includes a strength component, or at least an element of motor control. In other words, mobility means the ability to move a joint through as big a range of motion with muscle and nervous system control.
Examples of this would be gymnasts or dancers being able to move their limbs through large ranges with strength, control and stability.
Another example would be a hockey goalie. Being able to have sufficient flexibility to stretch your leg, for example, in a specific direction to make a save is crucial, but it is just as important to be able for the hips to be mobile enough to move the goaltender through and around the crease with control even in the deepest and fullest ranges of joints.
In elite athletic training programs, mobility exercises are often done just after, or incorporated into the warm-up portion of the training session, whereas flexibility is best achieved by performing stretching exercises at the end of a session.
Both are important and require specific attention devoted to them.
Kerry Senchyna holds a bachelor of science degree in kinesiology and is owner of West Coast Kinesiology in
Maple Ridge.
