Three-dimensional assessment of the asymptomatic and post-stroke shoulder: intra-rater test-retest reliability and within-subject repeatability of the palpation and digitization approach

• Published in: Disability and rehabilitation Vol. 41; no. 15; p. 1826
• Main Authors: Pain, Liza A M, Baker, Ross, Sohail, Qazi Zain, Richardson, Denyse, Zabjek, Karl, Mogk, Jeremy P M, Agur, Anne M R
• Format: Journal Article
• Language: English
• Published: England 17.07.2019
• Subjects: Aged; Biomechanical Phenomena - physiology; Female; Humans; Male; Middle Aged; Palpation; Paresis - physiopathology; Physical Examination - methods; Range of Motion, Articular - physiology; Reproducibility of Results; Rotation; Shoulder Joint - physiopathology; Stroke - physiopathology; kinematics; Clavicle; scapula; humerus; hemiparesis; range of motion
• DOI: 10.1080/09638288.2018.1451924

Altered three-dimensional (3D) joint kinematics can contribute to shoulder pathology, including post-stroke shoulder pain. Reliable assessment methods enable comparative studies between asymptomatic shoulders of healthy subjects and painful shoulders of post-stroke subjects, and could inform treatment planning for post-stroke shoulder pain. The study purpose was to establish intra-rater test-retest reliability and within-subject repeatability of a palpation/digitization protocol, which assesses 3D clavicular/scapular/humeral rotations, in asymptomatic and painful post-stroke shoulders. Repeated measurements of 3D clavicular/scapular/humeral joint/segment rotations were obtained using palpation/digitization in 32 asymptomatic and six painful post-stroke shoulders during four reaching postures (rest/flexion/abduction/external rotation). Intra-class correlation coefficients (ICCs), standard error of the measurement and 95% confidence intervals were calculated. All ICC values indicated high to very high test-retest reliability (≥0.70), with lower reliability for scapular anterior/posterior tilt during external rotation in asymptomatic subjects, and scapular medial/lateral rotation, humeral horizontal abduction/adduction and axial rotation during abduction in post-stroke subjects. All standard error of measurement values demonstrated within-subject repeatability error ≤5° for all clavicular/scapular/humeral joint/segment rotations (asymptomatic ≤3.75°; post-stroke ≤5.0°), except for humeral axial rotation (asymptomatic ≤5°; post-stroke ≤15°). This noninvasive, clinically feasible palpation/digitization protocol was reliable and repeatable in asymptomatic shoulders, and in a smaller sample of painful post-stroke shoulders. Implications for Rehabilitation In the clinical setting, a reliable and repeatable noninvasive method for assessment of three-dimensional (3D) clavicular/scapular/humeral joint orientation and range of motion (ROM) is currently required. The established reliability and repeatability of this proposed palpation/digitization protocol will enable comparative 3D ROM studies between asymptomatic and post-stroke shoulders, which will further inform treatment planning. Intra-rater test-retest repeatability, which is measured by the standard error of the measure, indicates the range of error associated with a single test measure. Therefore, clinicians can use the standard error of the measure to determine the "true" differences between pre-treatment and post-treatment test scores.