Lateral epicondylitis, “tennis elbow” is by far the most common upper extremity injury noted in the recreational tennis population and comprises up to 85% of all elbow injuries. A mechanism of origin is thought to be the overuse of musculature along the dorsal (opposite off the palm side) forearm which connects to the bony prominence (lateral epicondyle) at the outer elbow.
Muscle Fatigue
As the musculature fatigues with continued play, more and more of the load fails to be dispersed through the muscle belly and falls upon the tendon. With recurring patterns of overuse, ie continued play even though painful, there is progressive trauma; where the tendon not only pulls too aggressively on the bone, but also begins to slowly tear loose from it’s bony anchor. If the pattern of overuse continues, the body lays down scar tissue and ultimately calcifies the tendon (potentially leading to a bone spur) in order to salvage the attachment.
The greatest force placed upon these structures occurs during the backhand at the point of ball and racquet impact. There are many muscles running along the dorsal side of the forearm that attach to the lateral epicondyle, the one that is most commonly injured is the extensor carpi radialis brevis (ECRB).
Study
A recent study (Hatch et al, The American Journal of Sports Medicine, Vol. 34, No. 12, p. 1977-1983.) investigated a common treatment option; that being the modification of the racquet grip size. Nirschl has described a hand measurement technique for determining a player’s recommended grip size following his assessment that using a grip either too big of small would cause altered muscle activity through the forearm. Utilization of this concept has now become main stream, but to date objective testing of this theorem has not utilized procedures and equipment to fully and accurately asses the muscle firing patterns of the forearm.
The current study placed fine wire electrodes within the muscles along the dorsal forearm of male and female collegiate tennis players to accurately test the magnitude of muscle firing while utilizing different grips sizes. A 4.5” grip was defined as the standard, and ¼” sizes greater and less than the standard were also tested; noting that these would be the practical modifications from the standard if in fact a grip change was to be made to help resolve one’s lateral elbow pain.
The study found that there was no significant difference in muscle activity in the ECRB with the different grip sizes. They concluded that racquet grip size within the aforementioned circumferences is unlikely to be a significant contributing factor in overuse injuries about the forearm and elbow in the tennis player.
Obviously there is anecdotal evidence that this does work with this study forcing us to look deeper. Does a small change in grip size modify motion elsewhere through the shoulder girdle and arm to lessen stress to the elbow? Would a change greater or less than ¼” bring about a significant difference in muscle activity?
This study further reinforces an alternative treatment option, one with a greater long term benefit, with the known fact that mechanical deficiencies through the hips, trunk and shoulder girdle place excess stress on the elbow with throwing and racquet activities. If one suffers from long standing lateral epicondylitis, an in-depth assessment of their serving and back hand mechanics will often identify the deficiency, leading to a rehab and conditioning program to resolve symptoms once and for all.