Mobility is the capacity to effect efficient movement in different directions, as the need arises. The human body is designed to execute movement in the three planes (left and right/sagittal, forward and backward/frontal, twisting/transverse). These planes of motion do not exist in vacuum. They function together in varied combination as is necessary. The movements of the spine, shoulders and hips are critical to human functioning, as well. The ability to seamlessly integrate them is of overall importance. Not only on an athletic level but also on a day to day level. The ability to move is enhanced by . . . wait for it . . . . movement. The design of the human body, of any terrestrial body, is predicated upon the principle of movement. Without movement, the human body loses functional capacity.
So, mobility of a joint is the degree to which the area (where two bones meet known as an articulation) is allowed to move before being restricted by the surrounding tissue (such as tendons, muscle, and ligaments). It is not flexibility (the absolute range of motion in a joint or system of joints, and the length of muscle that crosses the joint involved) but is related to it. There is also a requirement for stability because unencumbered mobility or flexibility can facilitate injury to the body. The movement of the right arm reaching down and across the body to retrieve an object while the left foot is forward is an example of how planes of motion and spinal movement combine in the performing of an action as an example of mobility. Similar positions could be achieved when reaching up but with a slight variation of spinal and shoulder action. The human body is uniquely designed as to the requirement for the stability and mobility in the bi-pedal position.
Bending forward, backward, leaning left to right, twisting left to right coupled with reaching in various directions and squatting are the basis of movement for the human body. These movements should not drastically decrease as one ages. They are basic movements. The ability to access and express them deteriorates in the absence of their being engaged. While there is no question that range of motion tends to diminish with aging (Araújo 2008; Barnes et al. 2001; Beighton et al. 1973; Doriot and Wang 2006; Intolo et al. 2009; Roach and Miles 1991), it is still unclear if all major joints behave similarly. If this is so, then what is the rate of decrease over the years. It is imperative that adults be strategic about including flexibility training into their workouts, because maintaining flexibility and physical function (mobility) while moving into middle and older adulthood is associated with better quality of life and independent living.”
Expressing mobility does not require that one be able to contort the body into various positions. It does not require the ability to shape the body into varying, extreme degrees of reaching, twisting, jumping, etc. Mobility is the ability to move to the degree that is necessary to effect an action. To do this requires that the body actually move. That is all