Three-dimensional analysis versus goniometric measurement of total active elevation in normal subjects

BackgroundMultiple planes of motion have been reported for shoulder elevation performed by visual inspection with a goniometer. It is typically measured by a clinician who is standing or sitting at the side of the patient. Instead, accurate assessment of shoulder elevation must be performed by using a plane of reference that is perpendicular to the plane of motion being measured.MethodsThree repetitions of humeral elevation in the sagittal, scapular, and coronal planes were performed in a random order and measured by goniometry and three-dimensional (3D) electromagnetic sensors. A guide bar was used to control the initial plane of motion for the sagittal and coronal planes. The plane of motion at 90° and at peak elevation was recorded for each of the 3 defined planes. A goniometer was used to measure the range of maximal elevation performed in each plane, for each subject, by visual inspection.ResultsThe 3D data revealed that subjects consistently moved toward scaption as the extremity moved above 90° of elevation, regardless of the initial plane of motion. Significant differences were seen in the goniometric data for the plane of motion at 90° (P = .00) in flexion, abduction, and scaption. Goniometric measurements revealed greater maximum elevation angles in comparison to the 3D kinematic measurements.ConclusionsMaximal glenohumeral elevation occurred near the plane of the scapula in all subjects, regardless of the plane in which elevation was initiated. Goniometric measurement of total elevation resulted in greater range of motion measurements than actually occurred because the observer was not routinely positioned in a plane perpendicular to the plane of actual elevation of the upper extremity.