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.

The purpose of this investigation was to determine the effects of passive mobilization and active exercises in patients with painfully restricted shoulders. Twenty patients with painful glenohumeral restrictions were randomly placed in one of two groups. The experimental group received mobilization and active exercises two to three times per week for 4 weeks. The controls received only active exercises. Pain questionnaires were answered and isolated glenohumeral mobility measurements were taken initially and at weekly intervals during the 4 weeks of treatment. With the exception of internal rotation in the control groop, all motions increased significantly from baseline in both groups. Passive abduction improved significantly more in the mobilization group than in the control group. Pain scores decreased more in the mobilization group; however, the difference between the groups was not significant. The results suggest that joint mobilization and exercises are clinically effective in the treatment of painfully stiff shoulders.

J Orthop Sports Phys Ther 1985;6(4):238-246.

Since the initial symptoms usually include pain, an entrapment of the suprascapsular nerve may be mistaken for a shoulder disorder of musculoskeletal origin. However, upon examination, glenohumeral weakness during abduction, flexion, and external rotation with concomitant atrophy of the spinati muscles may be evident. Documentation is made with electroneuromyographic testing. Stretching the nerve is contraindicated; therefore, patients should be instructed to avoid activities which require scapular protraction and glenohumeral horizontal adduction. Furthermore, as the nerve heals, exercises to strengthen the weak muscles should be of benefit.

J Orthop Sports Phys Ther 1985;6(4):254-258.