The Effect of the Forearm Support Band on Forces at the Origin of the Extensor Carpi Radialis Brevis: A Cadaveric Study and Review of Literature

Author(s): Meyer NJ, Pennington W, Haines B, Daley R

Source: J of Hand Therapy 15:179-184, 2002

Summary:

The treatment of epicondylitis remains controversial and ill-defined.  The large sample size required and the placebo effect makes clinical analysis difficult.  This study utilizes a cadaver model to measure force reduction at the extensor carpi radialis brevis origin with application of a forearm support band at various pressures. A clinical cohort was used to substantiate the model. The cadaver portion of the project placed a forced transducer along the extensor carpi radialis brevis origin.  A blood pressure cuff was used to simulate a forearm support band and the pressure was regulated.  Various loads were applied to the extensor carpi radialis brevis tendon distally via a pulley at different cuff pressures.
 
As the pressure in the forearm support band (i.e., blood pressure cuff) increased, there was a reduction in force across the tendon origin.  Only four cadavers were utilized, which complicates the statistical analysis.  Nonetheless, a graduated force reduction was noted with increasing cuff pressures at 5 and 15 pounds of applied force.  The authors also measured the forearm band pressure applied in nine patients.  The average force at which the cuff was applied was 45 ? 25mm of mercury.

Lateral epicondylitis remains a perplexing problem with an unclear treatment algorithm.  This project attempted to develop a model that simulated the clinical scenario. Previous studies have noted a decrease in the electromyographic activity of the extensor carpi radialis brevis after application of various forearm bands.  This cadaver study indicates that the band does create a second “origin” and thereby decreases the force across the proximal tendon origin.  The study does possess many of the limitations inherent in a cadaver experiment.  However, the force transducer measurements do support the rationale for counterforce bracing of epicondylitis.  It is unclear if this intervention actually alters the natural history of this common and most often self-limiting condition.  

 

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J of Hand Therapy