Glenohumeral joint loading is impacted by rotator cuff tear severity during functional task performance

Movement compensation is driven by the deltoid and teres minor muscles following severe rotator cuff tear

“…This study used eight computational musculoskeletal models of the upper limb representing increasing rotator cuff tear severity, as described in our prior work (Khandare et al, 2022;Pataky et al, 2021;Saul et al, 2015) (Fig. 1).…”

“…To represent different levels of rotator cuff tear severity, the peak isometric force parameter for muscle actuators of rotator cuff muscles were systematically reduced to develop seven different tear severity models. Modeled tear severities modeled ranged from no rotator cuff tear (100% nominal peak isometric force for all muscles) to a massive, three tendon tear (0% supraspinatus, 25% infraspinatus, 25% subscapularis of the nominal peak isometric force), as described previously (Pataky et al, 2021).…”

“…Previous work has used a computational model to show that changes in glenohumeral loading magnitude and orientation occur with increasing rotator cuff tear severity during the performance of dynamic tasks (Pataky et al, 2021). During task performance, the glenohumeral joint contact force, which is the force the humerus applies to the glenoid fossa of the scapula, decreases in magnitude as rotator cuff tear severity increases.…”

“…A computational model allows prediction of the anticipated muscle compensation patterns in the context of increased rotator cuff tear severity. Increased rotator cuff tear severity has been shown to result in altered joint loading (Pataky et al, 2021), however, it is unclear how muscles are changing their force contribution to enable task performance in the context of a rotator cuff tear. Limited literature is available to provide guidance on muscle compensation following rotator cuff tears (Hawkes et al, 2012;Veen et al, 2021) and it is currently unknown how these muscular responses may differ with cuff tear severity.…”

Glenohumeral Joint Force Prediction with Deep Learning

“…The glenohumeral (GH) joint force refers to the force exerted by the humerus on the glenoid fossa (Pataky et al, 2021). Although direct in vivo measurement of this force is not feasible, except with instrumented prostheses (Bergmann et al, 2011), computational musculoskeletal models (MSM) enable its prediction (Sarshari et al, 2021a).…”