Study Design: Randomized clinical trial. Objectives: To investigate the clinical efficacy of the addition of the Protonics system to a standard exercise-based patellofemoral rehabilitation protocol. Background: The Protonics system has been suggested as an intervention for patients with patellofemoral pain syndrome (PFPS). However, the effects of this system have not been compared to the effects associated with traditional exercise-based rehabilitation alone. Methods and Measures: Seventeen of 34 females (mean age, 28 years; range, 13-55 years) diagnosed with PFPS were randomly assigned to wear the Protonics system while participating in a conventional exercise-based rehabilitation program. Functional and patient-reported outcome measures were evaluated, including Kujala score and the lateral step-up test. In addition, measurements of hip internal and external rotation, hip extension, and iliotibial band muscle length were compared between groups. Results: Patients in both groups demonstrated improvement in Kujala score (P<.001), performance on the lateral step-up test (P<.001), and pain during the step-up test (P<.001) at the conclusion of the study. However, there was no difference between groups with respect to improvement in Kujala score (P = .33), step-up test performance (P = .47), or pain during the step-up test (P = .24). Patients using the Protonics system demonstrated greater gain in passive hip extension (P = .023) and increased hip external rotation motion (P = .017) at discharge versus patients treated with exercise alone. However, there was no difference in iliotibial band flexibility (P = .80) or hip internal rotation motion (P = .09) between groups. A greater proportion of patients in the Protonics group reported no pain with step-up testing at each 2-week interval. However, the 2.2 fewer visits required by patients in the Protonics group to meet discharge criteria did not achieve statistical significance (P = .08). Conclusions: Patients using the Protonics system demonstrated a shift in available hip rotation and increased passive hip extension flexibility. However, these changes were not outside the bounds of potential measurement error and did not translate into significant functional differences from a similar group treated with exercise alone. The economic implications of an average 2.2-visit decrease in treatment sessions per patient using the Protonics system are uncertain. J Orthop Sports Phys Ther. 2005;35(4):210-219. Key Words: anterior knee pain, hip rotation, Kujala score, therapeutic exercise

Study Design: Two-group comparison. Objective: To compare scapular kinematics during arm elevation between groups distinguished by pectoralis minor resting length. Background: Studies have demonstrated that individuals with subacromial impingement have altered scapular kinematics, such as loss of posterior tipping and increased internal rotation. One proposed mechanism for these alterations is an adaptively short pectoralis minor. This anterior scapulothoracic muscle may impact normal scapular kinematics if adaptively short. Methods and Measures: Fifty volunteers without shoulder pain were divided into long or short groups according to normalized pectoralis minor resting length. An electromagnetic motion capture system determined the angular orientation of the scapula, humerus, and trunk during arm elevation in 3 separate planes. Groups were compared for 3-dimensional scapular orientation relative to the trunk at arm elevation angles of 30°, 60°, 90°, and 120°, using a mixed-model analysis of variance (ANOVA). Results: There were statistically significant interaction effects between group and arm elevation angle for scapular tipping in all planes of arm elevation, with the scapula for the short group staying anteriorly tipped at higher angles. There was also a significant interaction for scapular internal rotation at lower arm elevation angles in the coronal plane only, with individuals with a shorter pectoralis minor demonstrating a more internally rotated scapula. Conclusions: The group distinguished by a short pectoralis minor demonstrated scapular kinematics similar to the kinematics exhibited in earlier studies by subjects with shoulder impingement. These results support the theory that an adaptively short pectoralis minor may influence scapular kinematics and is therefore a potential mechanism for subacromial impingement. J Orthop Sports Phys Ther. 2005;35(4):227-238. Key Words: biomechanics, impingement, muscle, shoulder, 3-dimensional

Study Design: Cross-sectional descriptive study. Objectives: To examine the factors of gender and age, stratified by 10-year increments, on hamstring muscle length (HML) as measured by passive straight leg raise (PSLR) and popliteal angle (PA). Background: Differences in HML between men and women have not been examined for a large group of healthy adults over a wide range of ages. The usefulness of these data is to provide some typical values of HML for future reference. Methods and Measures: Two hundred fourteen adults (108 women, 106 men; age range, 20-79 years) with no known history of hip or knee joint disease and no history of recent hamstring strain participated in the study. PSLR (trunk-thigh angle) and PA (thigh-leg angle) were estimated with a goniometer. A 2-way analysis of variance (ANOVA) was used to analyze the effects of 2 independent variables (gender and age) on 2 dependent variables (PSLR and PA). Statistical significance was established at a<.05. Results: HML differed significantly (P<.001) between genders for both methods of measurement, with females demonstrating greater flexibility than their male counterparts. The difference between genders was 8° for PSLR and 11° for PA. HML was not influenced by age. Conclusions: This study provides physical therapists with typical values of HML in healthy men and women. J Orthop Sports Phys Ther. 2005;35(4):246-252. Key Words: flexibility, hip extensors, lower extremity, straight-leg raise