Shoulder Muscle Activation During Aquatic and Dry Land Exercises in Nonimpaired Subjects

Donald T. Kirkendall, Lori A. Roskin, Kevin P. Speer, Bryan T. Kelly
Study Design: Randomized, single blind experimental design using electromyography to measure shoulder muscle activation in nonimpaired subjects. Objectives: To compare the muscle activation of rotator cuff and shoulder synergists during rehabilitation exercises performed in water or on dry land. Background: Early motion is critical to restoration of normal shoulder function. Aquatic therapy has been promoted as a method for increasing range of motion while minimizing stress on the shoulder. Methods and Measures: The integrated electromyography amplitude of 6 muscles of the shoulder girdle was examined on the nondominant shoulders of 6 subjects (supraspinatus, infraspinatus, and subscapularis, anterior, middle, and posterior deltoids). Each subject performed elevation (0� to 90�) in the scapular plane with neutral rotation on land and in water at 3 different speeds of elevation (30�/s, 45�/s, and 90�/s). The mean percentage of the maximal voluntary contraction was determined for each of the 3 test speeds on land and in water. Comparisons between water and dry land were made with a repeated measures analysis of variance. Results: For all 6 muscles tested, muscle activation during the 30�/s test speed and all muscles tested at the 45�/s test speed was significantly less when performed in water versus when performed on land. For example, electromyography activation of the supraspinatus muscle was 16.68% of a maximal voluntary contraction when elevation at was performed at 30�/s on dry land versus 3.93% when performed in water. Conclusion: These data suggest that shoulder elevation in the water at slower speeds resulted in a significantly lower activation of the rotator cuff and synergistic muscles. This decreased muscle activation during aquatic physical therapy allows for earlier active motion in the postoperative period without compromising patient safety. J Orthop Sports Phys Ther. 2000;30(4):204-210. Key Words: aquatic therapy, electromyography, muscle, rotator cuff, shoulder

The Hip Joint: Arthroscopic Procedures and Postoperative Rehabilitation

Keelan R. Enseki, Peter Draovitch, Bryan T. Kelly, RobRoy L. Martin, Marc J. Philippon, Mara L. Schenker

Recent technological improvements have resulted in a greater number of surgical options available for individuals with hip joint pathology. These options are particularly pertinent to the relatively younger and more active population.

The diagnosis and treatment of acetabular labral tears have become topics of particular interest. Improvements in diagnostic capability and surgical technology have resulted in an increased number of arthroscopic procedures being performed to address acetabular labral tears and associated pathology. Associated conditions include capsular laxity, femoral-acetabular impingement, and chondral lesions. Arthroscopic techniques include labral tear resection, labral repair, capsular modification, osteoplasty, and microfracture procedures.

Postoperative rehabilitation following arthroscopic procedures of the hip joint carries particular concerns regarding range of motion, weight-bearing precautions, and initiation of strength activities. Postoperative rehabilitation protocols that have been typically used for surgeries such as total hip arthroplasty are often not sufficient for the population of patients undergoing arthroscopic procedures of the hip joint. Postoperative rehabilitation should be based upon the principles of tissue healing as well as individual patient characteristics. As arthroscopic procedures to address acetabular labral tears and associated pathology evolve, physical therapists have the opportunity to play a significant role through the development of corresponding rehabilitation protocols.

J Orthop Sports Phys Ther. 2006;36(7):516-525. doi:10.2519/jospt.2006.2138

Key Words: clinical research, hip, labrum, lower extremity

Journal of Orthopaedic & Sports Physical Therapy - Bryan T. Kelly, MD

Shoulder Muscle Activation During Aquatic and Dry Land Exercises in Nonimpaired Subjects

The Hip Joint: Arthroscopic Procedures and Postoperative Rehabilitation