The measurement of three dimensional scapulohumeral kinematics – a study of reliability

• Published in: Clinical biomechanics (Bristol) Vol. 14; no. 4; pp. 287 - 290
• Main Authors: Barnett, N.D, Duncan, R.D.D, Johnson, G.R
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.05.1999
• Subjects: Analysis of Variance; Biomechanical Phenomena; Electromagnetic Phenomena; Gait analysis; Humans; Humerus - physiology; Joints (anatomy); Kinematics; Musculoskeletal system; Palpation; Patient rehabilitation; Polhemus; Range of Motion, Articular - physiology; Reliability; Reproducibility of Results; Scapula; Scapula - physiology; Shoulder; Shoulder Joint - physiology; Three dimensional; Scapula; Shoulder; Kinematics; Polhemus
• ISSN: 0268-0033; 1879-1271
• DOI: 10.1016/S0268-0033(98)00106-5

Objective: To validate a system, using electromagnetic movement sensors, for the simultaneous measurement of scapular and humeral positions. Design: The study was designed to analyse the repeatability and to quantify the inherent measurement errors, using two observers to measure the movements of five normal subjects. Background: Following an earlier study of a system to measure three dimensional scapula motion, the method has been developed to incorporate simultaneous measurement of humeral and scapular position using a new design of scapula locator and a two-channel measurement system. Methods: The system was used to measure the scapula movements accompanying abduction of the shoulder. The scapula locator was applied at 10° intervals of abduction. This was measured initially using a fluid filled goniometer, but, in a second part of the study, using an additional motion sensor. Results: In the single channel study, the 95% confidence intervals were less than 4° and 10 mm. When simultaneous measurement of arm position was performed the confidence intervals were little changed. Conclusions: A new system for the measurement of scapulohumeral relationships has been shown to have good inter-and intra-observer reliability. This study opens the way for a full investigation of the scapula motion accompanying three dimensional shoulder motion in both normal subjects and in patients having shoulder pathology. Relevance This study demonstrates a validated system suitable for the clinical study of the kinematics of both the normal and the pathological shoulder.