Reproducibility of Isokinetic Peak Torque and Angle at Peak Torque in the Shoulder Joint

Abstract

Adequate reliability studies of knee flexion and extension are currently available for isokinetic measurements, but not for the shoulder joint. For this reason, this study examines the variability (%) in the determination of peak torque (PT) and the angle at peak torque (AP) in the test-retest procedure. Differentiation is made between the various types of work (concentric, isometric, eccentric) and the degrees of freedom in the shoulder joint (flexion/extension, abduction/adduction, external rotation/internal rotation). The results show a variability of PT for concentric measurements of 15.0%-19.0% for all degrees of freedom; for flexion/extension and abduction/adduction in isometric and eccentric work, the variability is 17.5%-25.3%. External and internal rotation show generally greater deviation (29.0%-35.3%), except in concentric work. The angle at peak torque can only be reproduced to a limited degree (25.1%-41.1% variability). It is concluded that lower reproducibility can be attained for the shoulder joint compared to the knee joint, depending on the degree of freedom and exercise form tested. It appears meaningful to cite only ranges for the angle at peak torque.

Reliability of Isokinetic Assessment of Shoulder-Rotator Strength: A Systematic Review of the Effect of Position

“…Three studies 20,21,27 did not report the plane of the shoulder position. Seven studies 2,15,21,27,32,35,38 reported both relative and absolute indices of reliability, but 7 studies 11,25,33,34,[39][40][41] reported only relative indices.…”

“…The highest QAREL rating was 6/11, with an average of 4.2 ± 1 (range 2-6). Numbers and methodological quality of studies dealing with supine and standing positions were poor: 6 studies 11,20,26,33,34,40 for 3 positions, with QAREL scores from 2 to 4. Individual QAREL scores for each included study are reported in Table 2.…”

“…[21][22][23][24] The reliability of ER-and IR-muscle strength measurements is a controversial issue because of differences in the methodological aspects and design of studies. 6,20,21,25,26 One of these methodological points is the position used during tests, including the subject's posture (sitting, standing, or supine) and the shoulder posture (in the frontal or scapular plane with 0°, 45°, or 90° of shoulder abduction), which together determine the alignment of the joint axis. 5,6,24 The influence of the position on measurement reliability is not known.…”

“…5,6,19 However, given the kinematics of the shoulder joint and its relatively extensive mobility, questions have been raised about the reliability of isokinetic shoulder assessment. 15,20 Although it is influenced by many factors (mechanical aspects, subjects, joints, and testing protocols), 19,21 the assessment position, including the position of the shoulder (shoulder posture [21][22][23] and joint-axis alignment 16 ) and the position of the body (sitting, supine, or standing and stabilization), appears to be a determining factor. [21][22][23][24] The reliability of ER-and IR-muscle strength measurements is a controversial issue because of differences in the methodological aspects and design of studies.…”

Force-Velocity Parameters of Knee Flexors and Extensors in 10-12-Year-Old Children with Spinal and Knee Diseases

“…The subject's thigh and pelvis were stabilized with dynamometer straps to eliminate any facilitating movements. Before the test each subject flexed the knee to the maximum and performed three submaximal flexion and extension movements at the knee joint to get acquainted with a given load [10].…”