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.
['Wight|Jeff T|JT|', 'Grover|Guy B|GB|', 'Chow|John W|JW|', 'Borsa|Paul A|PA|', 'Wikstrom|Erik A|EA|', 'Tillman|Mark D|MD|']
D056352:Athletes D006801:Humans D008297:Male D016059:Range of Motion, Articular D015203:Reproducibility of Results D012399:Rotation D012782:Shoulder D012785:Shoulder Joint D019415:Torque D055815:Young Adult
Shoulder External rotation Flexibility Internal rotation