A three-dimensional regression model of the shoulder rhythm

de Groot, J. H.<sup>1</sup>; Brand, R.<sup>2</sup>

Affiliations

¹Department of Measurement and Control, Faculty of Mechanical Engineering and Marine Technology, Delft University of Technology, Delft, Netherlands

²Department of Medical Statistics, Faculty of Medicine, Leiden University Medical Centre, Leiden, Netherlands

Abstract and keywords

Objective: The development of a thorax-fixed regression model for the shoulder which statistically predicts the orientation of the clavicle and the scapula from the humerus orientation.

Background: The application of three-dimensional position recording systems to the shoulder mechanism is limited to laboratory conditions. Studies in the field of ergonomics and sports require a method that can be applied in situ. It was found that the relation between the scapular and the humeral motions is consistent. In order to facilitate the biomechanical research on the shoulder a descriptive statistical model of the shoulder rhythm was developed.

Methods: The orientation of the shoulder bones of 10 subjects was determined in a large range of 23 humerus positions. The elbow was flexed in a splint and the arm was fully supported. The subjects exerted a 20 N external abduction and adduction force at the elbow in a plane perpendicular to the humerus. Other forces and moments were mechanically minimized. During the task the postures of the shoulder were recorded. The linear regression equations for the clavicular and scapular orientations were determined by means of a repeated measurements multi-variate analysis of variance for the co-variates: humerus orientation, initial orientation of the clavicle and the scapula, external force direction, gender and morphological characteristics of the subjects.

Results: The orientation of the clavicle and the scapula was predicted by five linear regression equations, including the co-variates: humerus orientation, external force direction and initial position. Morphology and gender did not significantly contribute to the clavicular and scapular orientation predictions.

Conclusions: A statistical model is developed for the prediction of clavicular and scapular orientations, based on the humerus position, the initial posture and the direction of the external force. The model fitted well on an independent set of recorded position data for a different group of subjects.

Relevance: Morphological data of the shoulder girdle and gender did not significantly contribute to the model structure.

Keywords: Shoulder; Kinematics; Scapulo-humeral rhythm; Shoulder rhythm; Linear regression

Links

DOI: 10.1016/S0268-0033(01)00065-1

PubMed: 11714550

WoS: 000172157100003

History

Received: 2001-01-26

Accepted: 2001-06-25

Online: 2001-11-13

Cited By (14)

Year	Entry
2005	Holzbaur KRS, Murray WM, Delp SL. A model of the upper extremity for simulating musculoskeletal surgery and analyzing neuromuscular control. Ann Biomed Eng. June 2005;33(6):829-840.
2015	Saul KR, Hu X, Goehler CM, Vidt ME, Daly M, Velisar A, Murray WM. Benchmarking of dynamic simulation predictions in two software platforms using an upper limb musculoskeletal model. Comput Methods Biomech Biomed Eng. 2015;18(13):1445-1458.
2024	Mattar LT, Mahboobin AB, Popchak AJ, Anderst WJ, Musahl V, Irrgang JJ, Debski RE. Individuals with rotator cuff tears unsuccessfully treated with exercise therapy have less inferiorly oriented net muscle forces during scapular plane abduction. J Biomech. January 2024;162:111859.
2022	Vancleef S, Wesseling M, Vander Sloten J, Jonkers I. Musculoskeletal modeling-based definition of load cases and worst-case fracture orientation for the design of clavicle fixation plates. J Orthop Res. September 2022;40(9):2179-2188.
2018	McFarland DC. Spatial Dependency of Muscular and Joint Loading During Dynamic Submaximal Pushing and Pulling [PhD thesis]. North Carolina State University; 2018.
2017	LeVasseur CM. A Musculoskeletal Model of the Upper Extremity to Quantify Ligament Contribution to Glenohumeral Stability [Master's thesis]. St. Louis, MO: Saint Louis University; 2017.
2005	Holzbaur KRS. Upper Limb Biomechanics: Musculoskeletal Modeling, Surgical Simulation, and Scaling of Muscle Size and Strength [PhD thesis]. Stanford University; September 2005.
2011	Webb JD. Contributions of the Deltoid and Rotator Cuff to Shoulder Mobility and Stability: A 3D Finite Element Analysis [PhD thesis]. Stanford University; August 2011.
2010	Rankin JW. The Influence of Altering Wheelchair Propulsion Technique on Upper Extremity Demand [PhD thesis]. University of Texas at Austin; August 2010.
2015	Slowik JS. The Relationships Between Muscle Weakness, Wheelchair Propulsion Technique and Upper Extremity Demand [PhD thesis]. University of Texas at Austin; August 2015.
2022	Walford SL. The Interactions Between Hand Pattern, Shoulder Pain and Upper Extremity Demand in Manual Wheelchair Users [PhD thesis]. University of Texas at Austin; May 2022.
2011	Daly M. Adaptations Following Upper Extremity Resistance Training in Older Adults [PhD thesis]. Winston-Salem, NC: Wake Forest University; May 2011.
2014	Vidt ME. Muscle Structure and Function in Older Adults With a Rotator Cuff Tear [PhD thesis]. Winston-Salem, NC: Wake Forest University; April 2014.
2015	Santago AC II. Implications of Aging and Degenerative Rotator Cuff Tears for Upper Limb Muscle Morphology, Strength, and Function [PhD thesis]. Winston-Salem, NC: Wake Forest University; May 2015.