Biomechanics of the shoulder.

The terminology of engineering has made biomechanics unnecessarily confusing and intimidating to many clinicians. Frankel and Burnstein's4 classic text on orthopedic biomechanics was so difficult to understand that it was not fully appreciated. Fortunately, the gap between mechanical engineers and clinicians has been ~losing.'C~o - operation between engineers and clinicians has led to the translation of the confusing mathematical properties of biomechanics into readable and clinically applicable terms (for example, see Frankel and Nordin5). This review will be in keeping with the current trend of basic, clinically applicable biomechanics. Specifically, we propose to review the function of the shoulder girdle, particularly scapulohumeral control of the arm, describing the pertinent mechanical properties. The function of the bones and joints will be,related to their structure and forces applied to them. This review should not be considered an exhaustive biomechanical analysis of the structures involved. References have been provided for that purpose. J Orthop Sports Phys Ther 1985;6(4):229.334.