The Elbow Joint-Part 2

The large majority of the bodys joints, including the elbow, are capable of producing what are known as accessory movements, small sliding and gliding movements occurring inside a joint which a person cannot perform on their own. Accessory movements are vital for the normal use of a joint and are easily disrupted, limited or abolished by trauma or postural bodily misuse. The elbow accessory movements are very limited in size and consist of a small sideways gapping of the joint, which does not make a large difference to the ability to achieve various positions with the hand but does increase functional ability.

These little accessory movements may not seem to be able to make a difference to the use of the elbow joint but they can permit a slight lengthening of the extensor muscles of the wrist when we are trying to adjust our arm position to get hold of something. If a muscle is stretched slightly this increases the contractibility and thereby its function. In this case the extensor muscles can extend the wrist more successfully to allow the flexor muscles to apply grip strength.

The muscles of the extensor part of the forearm can become short and tight, especially if the opposing muscles become over strong, restricting their function in being able to hold the wrist in an effective posture for a functional hand grip. The ability of the radial head to rotate freely within its ligamentous strap is also key to permitting the hand to adopt a huge range of potentially required positions.

The two dominant movement patterns we perform again and again every day for hundreds of repetitions typically are turning the forearm over so the hand is palm up and pulling the wrist back with the palm down. Both the main muscles which are concerned with these very common actions originate from the same anatomical location on the outside of the forearm near the elbow. Overuse of these muscle groups can lead to increased tone in this lateral compartment of the elbow, causing shortening and loss of elasticity of the tissues. A cycle of tightening, muscular compensation and further tightening can develop.

If the elbow is bent and the wrist is extended in an activity which is repetitive and lasts for some time then this can be damaging as the elbow bend loosens the extensor muscles a little and reduces their effectiveness to some degree. Examples of this activity are using a computer mouse or playing a piano. Continuous postural stresses from repeated actions over a long period can permanently cause tightening as the muscles continually recover. All this prepares the elbow for a time when a relatively minor added stress changes the typical, irritating achy joint into a highly acute and painful problem.

A common elbow musculoskeletal problem is tennis elbow or lateral epicondylitis. If a person overdoes a physical action they are not accustomed to they can cause acute trauma to the muscular origin and acute pain onset. A slower development of this condition is more typical, with low level problems until suddenly more severe pain results from relatively minor trauma. In tennis itself using the backhand stroke is a particular stressor on the common extensor origin but many other activities can mimic this activity and produce the same painful result.

If the hand and forearm are engaged in strenuous activity gripping or holding an object they may traction the tightened tissues around the extensor origin and damage some of the fibres at the junction between the tendon and the bone. Repetitive cycles of this activity can allow the pain to become gradually worse whilst the precipitating stresses reduce in severity, making the whole pattern more irritable. The continual injury and scarring process which repeats makes the injured areas tighten up further and expose them to the danger of sudden stretching stresses. Often irritating, the pain of tennis elbow can severe.