Clinical isokinetic characteristics for professional ballet artists were determined preseason and at "peak" season. Twenty-eight dancers (equal N/sex) were studied at 45, 90, and 180 per second. The data indicated that, while male relative torques were similar to other athletes previously reported, the females were lower than most other female athletes. With training, males showed virtually no change at the slow and intermediate speeds, but improved at 180 per second, while females improved at all three speeds but, significantly, only at 180 per second. Males generated significantly more torque than females and the torque-velocity characteristics between sexes were parallel. Clinical characteristics showed the dancers to have quadricep balance between legs and proportional (hamstrings/quadriceps) within legs (no effects of training on either). The data indicates that male dancers have characteristics similar to other athletes, that females are lower in relative torque than other female athletes, and that dance training affects only torque at functional velocities.

J Orthop Sports Phys Ther 1984;5(4):207-211.

Following repair of the anterior cruciate ligament, it is fairly typical for a patient to return to activity at approximately 12 months postsurgery. The purpose of the study was to quantify quadriceps size and function at 1 year postsurgery. Bilateral isokinetic torque measurements, tomographic scans, muscle biopsies, and anthropometrics were performed on 13 patients (3 females, 10 males) at 13 months post-surgery. The operative leg was 3% smaller in circumference, 10% smaller in total muscle area, 12% smaller in quadriceps area (all p < 0.05) and had a 9% larger subcutaneous fat area (p = 0.06). No difference in hamstrings area was seen. Isokinetic torques for the quadriceps were reduced by 11-15% in the operative leg (p < .05) with no difference seen between the hamstrings torques. Types I and II fibers were clinically smaller in both legs with the type II fibers being significantly (p < 0.05) reduced in the operative leg. It was concluded that 1) leg circumference was a poor indicator of muscle size due to the selective fat deposition in the operative leg, 2) the cross-sectional area of muscle was proportional to isokinetic torque at 240/sec, and 3) there were clinically and statistically significant isokinetic torque differences between quadriceps 13 months post-surgery.

J Orthop Sports Phys Ther 1988;9(7):245-249.

J Orthop Sports Phys Ther 1991;13(5):235-239.

J Orthop Sports Phys Ther 1993;17(5):247-251.

Key Words: ultrasound, conducting mediums, tissue temperature

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