title: Arm abduction strength and its relationship to shoulder geometry.
abstract: This study was conducted to test whether glenohumeral geometry, as measured through MRI scans, is correlated with upper arm strength. The isometric shoulder strength of 12 subjects during one-handed arm abduction in the coronal plane, in a range from 5 degrees to 30 degrees , was correlated with the geometries of their glenoid fossas. Seven parameters describing the glenohumeral joint geometry in the coronal plane were identified as having expected influence on shoulder strength. In addition to these, a new geometric parameter, named the area of glenoid asymmetry (AGA), was considered to reflect the concavity-compression mechanism as well as the inclination of the glenoid surface. As a result of the high correlation between the AGA and mean force and mean moment (0.80, p0.01 and 0.69, p <or= 0.05, respectively) at the glenohumeral joint in a coronal plane, the AGA was distinguished as a factor having influence on shoulder strength when an arm was abducted in a range from 5 degrees to 30 degrees .
authors.affiliation: Liberty Mutual Research Institute for Safety, 71 Frankland Road, Hopkinton, MA 01748, USA. Krystyna.Gielo-Perczak@libertymutual.com
authors.forename: Krystyna
authors.initials: K
authors.lastname: Gielo-Perczak
authors.forename: Simon
authors.initials: S
authors.lastname: Matz
authors.forename: Kai-Nan
authors.initials: KN
authors.lastname: An
mesh_terms: D000328:Adult; D001132:Arm; D001696:Biomechanical Phenomena; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009068:Movement; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000502:physiology*; D012785:Shoulder Joint / Q000033:anatomy & histology*