The Elbow " Part Two "
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 small movements may not look like they contribute much to the function of the elbow joint but they can. As we adjust the arm to grip something effectively the added movements of the elbow allow a slight lengthening of the wrist extensor muscles at times. A small amount of tension on a muscle enhances its ability to contract and increases its effectiveness, in this case the extending of the wrist so that the hand is in the right position for the strength of the grip to be applied.
Should the opposing muscle group, the flexors, dominate then the extensor muscle origin can become shortened and tight to a degree, limiting the ability of the extensor muscles to adapt wrist positions for useful holding and gripping. The radial head, normally rotating in its radial ligament, confers the precise positioning required to allow the hand to be placed and used in a huge variety of positions.
Pulling the wrist upwards with the palm pointing down and forearm rotation with elbow bend as the palm faces upwards are the two most common and useful arm functions, repeated countless times every day. The origin of both the sets of muscles which do these activities happens to occur very close on the same area of bone on the outside of the elbow. If this leads to overuse of this area the muscles can become tenser, shortening them and reducing tissue elasticity. A cycle can then occur where the initial stress is overuse, followed by the area becoming tight, then the arm compensating and becoming tighter once again.
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.
Tennis elbow is a widespread problem which often develops slowly as described, however the onset can be sudden and unexpected after a lot of physical work which can overstress the joints tissues and cause local inflammation and trauma. Typically the slower onset is more common with the more minor problems being present for some time until there is a sudden, often small trauma. The tennis backhand stroke is a good example of how to significantly stress the origin of the extensor muscles but other activities which reflect that kind of action can add up to the same.
Over tight muscles in the extensor origin are opposed by the strength of the gripping and holding applied, in cases causing an overstress to the junction between the bone and the tendon and local tearing of tissues from the bone. As a process this can repeatedly occur, with the initiating stress becoming less and less and the pain results becoming more troublesome and long-lasting. As the small scars continually form they contract and add to the local tightness and so the likelihood of painful stretching. Tennis elbow pain can be very severe so that it interferes with activities of daily living.