There seem to be some convincing references to "joint balance":

In addition, secondary procedures have been shown to be effective in helping to restore muscle and joint balance throughout the early years postinjury.
http://books.google.co.uk/books?id=Gx8G3WUJ24sC&pg=PA903&lpg...

The relative value of normal joint-balance varies with age, size, and occupation.
http://jbjs.org/article.aspx?articleid=31055

... the humeral head on the superior glenoid may occur secondary to the shoulder muscles functioning to maintain glenohumeral joint balance and congruency.
http://books.google.co.uk/books?id=ssX25YIdAFIC&pg=PA321&lpg...

The first application of intelligent orthopedic surgical technology is the OrthoSensor Knee Balancer, which insures proper joint balance and alignment during total knee arthroplasty.
https://docs.google.com/viewer?a=v&q=cache:9y-VTuLZPPQJ:www....

The intelligent instrument is embedded with sensors that quantify joint balance intra-operatively, so the surgeon can make adjustments to the soft tissues and optimize implant placement.
http://www.elvisgrandicmd.com/blog/

The older adults had similar amounts of joint movement as the young adults during balance recovery except for the thoracic-lumbar joint.
http://www.ncbi.nlm.nih.gov/pubmed/22618298

I also found in one medical dictionary "balanace articular -> joint balance".

I bit more context would have helped.

According to a book on physical therapy, "articular balance is the relationship of the two articulating joint surfaces from anatomical neutral throughout a full physiologic movement"

Giammatteo, Sharon. Integrative Manual Therapy for the Upper and Lower Extremities. United States: North Atlantic Books, 1998.