A device for characterizing humeral orientation

In cases of shoulder laxity or instability, physicians assess patients' humeral mobility by estimating the ranges of abduction and rotation over which the patient is pain-free. The present approach is quite subjective and shows poor intra- and inter-physician reliability. This paper describes a device we developed to accurately measure humeral orientation. The device does this by utilizing minimum constraint design to impose a consistent and repeatable axis of rotation on the shoulder joint which ensures that data from different patients assessed by different physicians can be reliably compared.