motion analysis, joint angles, instantaneous helical axis, work-related musculoskeletal disorders


To understand the mechanisms involved that lead to the high prevalence of work-related musculoskeletal disorders in sonographers, this motion capture study evaluated upper extremity kinematics during kidney scans. The purpose of this study was to provide an evaluation of joint ranges of motion during scanning, which could be helpful in assessing risk of injury. A Vicon MX motion capture system recorded reflective marker positions while four sonographers scanned a volunteer’s kidneys. The results indicated that sonographers were scanning with their shoulders in flexion, abduction, and external rotation. The elbows were in flexion and the wrists in extension in all cases with the exception of portions of one scan. Shoulder abduction and wrist extension angles exceeded acceptable published limits. These results could be used to improve patient and sonographer positioning, equipment adjustability, and transducer design.


Original Citation: Pocratsky, Jennifer, Blake Ashby, and Jeanine Beasley. "Upper Extremity Kinematics in Sonographers During Kidney Scanning." Journal of Diagnostic Medical Sonography (2013).