Scapular Kinematics by Sex Across Elevation Planes.

Scapular kinematics are important indicators of dyskinesis, often suggesting underlying shoulder pathology, but the influence of sex is unknown. This study's objective was to examine scapular kinematics in healthy males and females. Positions of surface-mounted reflective markers were tracked during arm elevation movements in 0°/30°/40°/60°/90°/120° planes.

Three-dimensional comparison of static and dynamic scapular motion tracking techniques.

The shoulder is complex and comprised of many moving parts. Accurately measuring shoulder rhythm is difficult. To classify shoulder rhythm and identify pathological movement, static measures have been the preferred method.

The roles of whole body balance, shoe-floor friction and joint strength during maximum exertions: searching for the "weakest link".

Exerting manual forces is critical during occupational performance. Therefore, being able to estimate maximum force capacity is particularly useful for determining how these manual exertion demands relate to available capacity. To facilitate this type of prediction requires a complete understanding of how maximum force capacity is governed biomechanically.

Spatial dependency of shoulder muscle demands in horizontal pushing and pulling.

Pushing and pulling account for nearly half of all manual material handling tasks. The purpose of this investigation was to develop a 3-D spatial muscle activity map for the right upper extremity during pushing and pulling tasks. Nineteen males performed 140 ramped directional hand exertions (70 push; 70 pull) at locations along three axes aligned with the anatomical planes.

Quantifying scapula orientation and its influence on maximal hand force capability and shoulder muscle activity.

Background: Non-neutral scapular orientations are often implicated as potential causes of shoulder pathologies. However, their specific influence on shoulder functional capabilities is largely unknown. This study objectively measured scapular orientation and quantified its influence on shoulder muscle activity levels and hand force capabilities during vertical and horizontal manual exertions.