Measuring Scapular Movement Using Three-Dimensional Acromial Projection

Abstract

Background The current jig standard for measuring scapulohumeral movement of the shoulder complex only allows for static measurements of scapular positioning. Methods We compared scapular positioning as determined by a scapular jig with that projected from a marker triad placed on the acromion process of the scapula using an infrared motion capture system. Nine individuals performed abduction and scaption shoulder movements while arm and shoulder positioning were recorded during static and dynamic trials. Virtual scapulae were projected from surface marker triads on participants' acromia and compared with the position of three scapular landmarks identified by placement of a customized plastic jig. Static and dynamic positioning at a series of angles was compared to the jig standard to determine validity of the technique. Results There were no statistically significant differences between the virtual projections and jig standard for scapular external rotation, upward rotation, and anterior‐posterior tilt planar measurements. Dynamic positioning correlated well with static projections, but virtual scapular projections generally overestimated upward rotation of the scapulae, as compared to the jig. This could potentially be corrected through the development of a linear correction factor. Conclusion Acromial projection allows for reproducible, non‐invasive dynamic video motion capture of the scapula.

Evaluation of the range of motion of scapulothoracic, acromioclavicular and sternoclavicular joints: State of the art

“…This method has the intrinsic limit of describing in two what is occurring in the three dimensions. 17,18…”

“…As previously said, differently from the superior and inferior extremity segments, the scapula rotates and glides right below layers of skin and soft tissues. 18…”

“…This method has the intrinsic limit of describing in two what is occurring in the three dimensions. 17,18 The obstacle in tracking the movements of the scapula appears to be the main obstacle to analyzing threedimensional shoulder movements. As previously said, differently from the superior and inferior extremity segments, the scapula rotates and glides right below layers of skin and soft tissues.…”

“…As previously said, differently from the superior and inferior extremity segments, the scapula rotates and glides right below layers of skin and soft tissues. 18 Technology innovations have led to an invasive or noninvasive 3D shoulder complex kinematics analysis both using electromagnetic tracking systems (ETS). 6 Through ETSs the physicians can individuate the position and orientation of sensors in space.…”

Análise biomecânica do ombro de nadadores após a realização de um teste de esforço máximo

“…Análises cinemáticas tridimensionais da articulação ET foram realizadas em variadas tarefas, incluindo movimentos de elevação do ombro em diversos planos de elevação, tarefas funcionais e gestos esportivos como o arremesso do basebol e o forehand do tênis (LUDEWIG et al, 2009;MEYER et al, 2008;ROGOWSKI et al, 2014;RUNDQUIST;OBRECHT;WOODRUFF, 2009;SHEIKHZADEH et al, 2008). Para isso foram utilizados sistemas de rastreamento, destacando-se os eletromagnéticos e os com câmeras infravermelhas (CHU et al, 2012;HOARD et al, 2013;KARDUNA et al, 2001;ROY et al, 2007 (LUDEWIG et al, 2009;MCCLURE et al, 2001). STRUYF et al, 2014).…”