A Comparison between Two Models of Shoulder Muscle Force Estimation

Abstract

Shoulder injuries are often related to rotator cuff muscles. Although there are various models for muscle force estimation, it is difficult to ensure that the results obtained with such models are reliable. The aim of the current study was to compare two models of muscle force estimation. Eight subjects, seven male and one female (mean age of 24 yr; mean height of 1.83 m), performed five isokinetic maximum concentric contractions of internal and external shoulder rotation. Two models with different algorithms were used. In both, the input data consisted of the measured internal rotation moment. Comparisons were made between the difference and the average results obtained with each model of muscle force estimation. There was reasonable agreement among the results for force between the two models for subscapularis, pectoralis major, and anterior deltoideus muscles results. Conversely, poor correlation was found for the latissimus dorsi, teres major, and middle deltoid. These results suggest that the algorithm structure might have a strong effect on muscle force estimation results.

Differences between clinician- and self-administered shoulder sustained mobilization on scapular and shoulder muscle activity during shoulder abduction: A repeated-measures study on asymptomatic individuals

“…Displacement of the humeral head might change the moment arm of shoulder muscles, impacting on muscle activity levels. With larger moment arm, a muscle would need less muscle force being generated to produce the same moment magnitude 5,33 It is important to understand how sustained mobilisations influence motor synergies of muscles. Our study includes measurements from multiple muscles as a first step in understanding the nature of interactions between muscles.…”

“…Differences between clinician-and self-administered shoulder sustained mobilization on scapular and shoulder muscle activity during shoulder abduction: A repeated-measures study on asymptomatic individuals. Musculoskeletal Science and Practice,30,[25][26][27][28][29][30][31][32][33]…”