The Elbow Joint
The elbow, like most of the body joints, exhibits what is called accessory movements, small gliding and sliding movements which occur inside the joint during movement but which cannot be performed independently. These small movements are essential to the function of a joint and are easily disturbed, reduced, or lost in injury or long term postural abnormality.
The elbow has small, hardly noticeable movements in a sideways direction as the joint gaps slightly under pressure.
This small gapping does not contribute greatly to the positions attainable by the wrist or hand but does make a functional contribution.
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.
If the opposite muscles dominate and the extensor compartment of the elbow and forearm is tight and shortened to some extent the muscles will not be able to position the wrist well to allow effective grip and holding of objects.
The rotatory ability of the radial head within its supporting ligament is also of high importance in allowing the hand to be positioned in virtually any number 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 that do these activities happens to occur very close to 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.
Elbow problems can be particularly brought on by using the arm for long periods with the wrist extended and the elbow bent, as the bent elbow slackens off the wrist extensors slightly and decreases their ability to be effective. This type of activity is especially apparent in playing the piano or using a computer mouse.
Repetitive activity over a long time can cause more permanent shortening of the muscles as they try and recover from continuous postural trauma.
This allows a small activity at some time to cause local trauma and convert a troublesome, achy problem into an acute and very painful injury.
Tennis elbow is a widespread problem that 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 that reflect that kind of action can add up to the same.
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 fibers 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 a tennis elbow can severe.