Posted by Stephen Messineo on Mon, Apr 05, 2010 @ 07:33 AM
The successful treatment of any injury depends not only on resolving the presenting problem but also addressing the factors which contributed to the cause of the problem. In order to do this the clinician must look towards the kinetic chain to understand where the problem might have come from.
What is the kinetic chain?
The kinetic chain referrers to a biomechanical model of movement; segments or joint of the body work as a whole to achieve motion. This chain of movement transfers forces from proximal (near to the body) to distal (away from the body). For example when kicking a football the kinetic chain of movement passes from the trunk through the hip, to the knee, onto the ankle and then is transmitted through the ball as it is struck by the foot. They say that a chain is only as strong as the weakest link, this is certainly true here. Any disruption to the kinetic chain, i.e. if one body part is not functioning normally, will mean that it places stress/strain on the other segments which will ultimately result in injury.
Consider the example of a tennis serve; an activity which uses the upper limb. The kinetic chain of the upper limb is as follows:
How can the trunk and shoulder cause problems at the elbow?
If the shoulder is not able to fully rotate inwards, then the wrist will have to compensate in order to get the racquet face to the ball at the correct moment (1), this places undue stress on the tendon which is likely to develop into injury if this pattern is repeated.
The Kinetic Chain and Tennis Elbow
The pain around the outside of the elbow joint that is associated with lateral epicondylitis (tennis elbow) develops when there is an abnormal level of stress on the tendon of the wrist extensors which attach the forearm muscles to the lateral epicondyle of the elbow. Issues surrounding the trunk and shoulder can be the cause of this undue stress to the tendon.
Rotator Cuff and Mid Thoracic Strengthening in the Treatment of Tennis Elbow
The rotator cuff consists of the tendons of 4 different muscles: Infraspinatus, Teres minor, Supraspinatus and Subscapularis. These muscles are responsible for providing stability at the shoulder by drawing the head of the humerus (arm bone) towards the glenoid fossa (socket of the shoulder joint). They also produce rotational movements around the shoulder. When strengthening around the shoulder the articulation between the scapula, ribs and thoracic spine (middle back) cannot be forgotten. The muscles around the middle back and shoulder blade work to extend the thoracic spine, and tuck the shoulder blade in towards the rib cage. This serves to place the glenoid fossa into its optimum position for movement of the shoulder.
By stabilizing and generating force within the first two links; it is possible to improve the efficiency of the kinetic chain, thus, helping to not only remove the stressful stimulus that may have caused the elbow injury, but also to prevent further problems in the future.
References
1. Occult periarthrosis of the shoulder - A possible progenitor of tennis elbow. LaBan, MM, Iyer, R and Tamler, MS. 11, 2005, American journal of physical medicine and rehabilitation, pp. 895-898.