Developing reliable measures of the passive torque-angle relationship for shoulder internal and external rotation: Implications for overhead athletics
Objectives: 1) Thoroughly assess shoulder flexibility by establishing the passive torque-angle relationship for internal and external rotation with the arm in an overhead athletics position (abducted 90°) and 2) test the reliability of four passive torque-angle measures. Design: Reliability study. Setting: Data were collected in a university biomechanics laboratory. Participants: Bilateral shoulder flexibility of 15 male college students (20.7 ± 1.1 y) was evaluated twice in two sessions over 7–10 days. Main outcome measures: For both ER and IR, reliability was assessed bilaterally (intra-session, inter-session, and inter-tester) for the traditional range of motion measure and three novel kinetic measures: torque at end ROM, resistance onset angle, rotational stiffness. This resulted in 48 total assessments. Results: Thirty-four assessments had good to excellent reliability (ICC ≥ 0.8), 10 had fair reliability (0.7 ≤ ICC < 0.8), and 4 had poor reliability (ICC< 0.7). Three of the four flexibility measures had a good overall ICC score: ROM (0.83), torque at end ROM (0.84), and resistance onset angle (0.81). The fourth, stiffness, had a fair overall reliability score (0.74). Conclusions: The passive torque-angle measures should be assimilated into clinical and research settings to determine the relevance to injury, rehabilitation, and performance.
Physical Therapy in Sport
Digital Object Identifier (DOI)
Wight, Grover, G. B., Chow, J. W., Borsa, P. A., Wikstrom, E. A., & Tillman, M. D. (2018). Developing reliable measures of the passive torque-angle relationship for shoulder internal and external rotation: Implications for overhead athletics. Physical Therapy in Sport, 33, 82–88. https://doi.org/10.1016/j.ptsp.2018.07.008