This was an interesting study that examined the effect of joint mobilization on the posterior capsule. Clinically, this suggests that small load mobilizations increase displacements of the posterior capsule; however they do not have long lasting effects. Low level mobilizations have been shown to decrease pain and may play a therapeutic effect in symptomatic patients; however improved motion will not occur due to structurally altering the posterior capsule. Larger load mobilization is required to increase posterior capsule mobility permanently and increase range of motion. In addition, with the increased tissue mobility there were no decreases in tissue stiffness, which indicate there was no tissue damage. The increased displacement may have occurred from breaking of collagen crosslinking and not necessarily due to collagen fiber damage. One limitation that was not mentioned in the study was that a normal capsule was used for testing. A hypertrophied or contracted capsule may require increased forces to cause similar results that were found in this study. Performing joint mobilizations in vivo might also result in physiologic responses that can’t be tested in a cadaver model but may cause additional structural or biochemical changes to the tissue or the joint. Clinical studies on overhead athletes are required to observe if joint mobilizations can increase range of motion overtime and also decrease shoulder and elbow injuries. What are other people’s experiences with posterior mobilizations in this population?
Written by: Stephen Thomas
Reviewed by: Jeffrey Driban