Axial musculoskeletal control (AMC) is a widely used concept and has been shown to be an important factor in physical performance, the pathophysiology of back pain and other MSK conditions. However, there is no agreement on a definition of AMC, nor a validated test for AMC and its application in clinical practice. Our aim was to develop a test for AMC using the Delphi method from a panel of experts with video and analysis of the footage. We found that the most commonly used tests were the maintenance of neutral pelvic position in single leg stance, single leg stance with eyes closed and single leg squat. We aim to further validate our findings by comparing this to surface EMG recordings and centre of gravity measurements in stress situations.

We describe five patients, seen since 1984, with posterior shoulder pain and isolated wasting and weakness of the infraspinatus. In four of these a ganglion in the spinoglenoid notch was demonstrated by MRI and in one recent case ultrasound scans were positive. Three patients have been treated by operation, but there was recurrence in one after five years. In each confirmed case, the ganglion straddled the base of the spine of the scapula, extending into both supraspinatus and infraspinatus fossae. The nerve was either compressed against the spine or stretched over the posterior aspect of the ganglion. Adequate surgical exposure is essential to preserve the nerve to the infraspinatus and to allow complete removal of the ganglion. This is difficult because of the location and thin-walled nature of the cysts.