Fabien Dal Maso1, Maxime Raison2, Arne Lundberg3, Anton Arndt4, Paul Allard5, Mickaël Begon5. 1. Laboratoire de Simulation et de Modélisation du Mouvement, Département de Kinésiologie, Université de Montréal, Montréal, Canada, 1700, Rue Jacques Tétreault, H7N 0B6 Laval, QC, Canada. Electronic address: fabien.dalmaso@gmail.com. 2. Polytechnique Montréal, Montréal, Canada, 2500, Chemin de Polytechnique, H3T 1J4 Montréal, QC, Canada. 3. Karolinska Institutet, Stockholm, Sweden Solnavägen 1, 171 77 Solna, Sweden. 4. Karolinska Institutet, Stockholm, Sweden Solnavägen 1, 171 77 Solna, Sweden; The Swedish School of Sport and Health Sciences, Stockholm, Sweden Lidingövägen 1, 114 33 Stockholm, Sweden. 5. Laboratoire de Simulation et de Modélisation du Mouvement, Département de Kinésiologie, Université de Montréal, Montréal, Canada, 1700, Rue Jacques Tétreault, H7N 0B6 Laval, QC, Canada.
Abstract
BACKGROUND: Glenohumeral translations have been mainly investigated during static poses while shoulder rehabilitation exercises, activities of daily living, and sports activities are dynamic. Our objective was to assess glenohumeral translations during shoulder rehabilitation exercises, activities of daily living, and sports activities to provide a preliminary analysis of glenohumeral arthrokinematics in a broad range of dynamic tasks. METHODS: Glenohumeral translations were computed from trajectories of markers fitted to intracortical pins inserted into the scapula and the humerus. Two participants (P1 and P2) performed full range-of-motion movements including maximum arm elevations and internal-external rotations rehabilitation exercises, six activities of daily living, and five sports activities. FINDINGS: During range-of-motion movements, maximum upward translation was 7.5mm (P1) and 4.7mm (P2). Upward translation during elevations was smaller with the arm internally (3.6mm (P1) and 2.9mm (P2)) than neutrally (4.2mm (P1) and 3.7mm (P2)) and externally rotated (4.3mm (P1) and 4.3mm (P2)). For activities of daily living and sports activities, only anterior translation during reach axilla for P1 and upward translation during ball throwing for P2 were larger than the translation measured during range-of-motion movements (108% and 114%, respectively). INTERPRETATION: While previous electromyography-based studies recommended external rotation during arm elevation to minimize upward translation, measures of glenohumeral translations suggest that internal rotation may be better. Similar amplitude of translation during ROM movement and sports activities suggests that large excursions of the humeral head may be caused not only by fast movements, but also by large amplitude movements.
BACKGROUND: Glenohumeral translations have been mainly investigated during static poses while shoulder rehabilitation exercises, activities of daily living, and sports activities are dynamic. Our objective was to assess glenohumeral translations during shoulder rehabilitation exercises, activities of daily living, and sports activities to provide a preliminary analysis of glenohumeral arthrokinematics in a broad range of dynamic tasks. METHODS: Glenohumeral translations were computed from trajectories of markers fitted to intracortical pins inserted into the scapula and the humerus. Two participants (P1 and P2) performed full range-of-motion movements including maximum arm elevations and internal-external rotations rehabilitation exercises, six activities of daily living, and five sports activities. FINDINGS: During range-of-motion movements, maximum upward translation was 7.5mm (P1) and 4.7mm (P2). Upward translation during elevations was smaller with the arm internally (3.6mm (P1) and 2.9mm (P2)) than neutrally (4.2mm (P1) and 3.7mm (P2)) and externally rotated (4.3mm (P1) and 4.3mm (P2)). For activities of daily living and sports activities, only anterior translation during reach axilla for P1 and upward translation during ball throwing for P2 were larger than the translation measured during range-of-motion movements (108% and 114%, respectively). INTERPRETATION: While previous electromyography-based studies recommended external rotation during arm elevation to minimize upward translation, measures of glenohumeral translations suggest that internal rotation may be better. Similar amplitude of translation during ROM movement and sports activities suggests that large excursions of the humeral head may be caused not only by fast movements, but also by large amplitude movements.
Authors: Gerald A Ferrer; R Matthew Miller; Jason P Zlotnicki; Scott Tashman; James J Irrgang; Volker Musahl; Richard E Debski Journal: Knee Surg Sports Traumatol Arthrosc Date: 2017-09-01 Impact factor: 4.342