Quantified measurement of subacromial impingement.

We modified the Hawkins impingement maneuver in order to develop a quantifiable and reproducible impingement test. The involved anatomic structures were examined with magnetic resonance imaging of 3 cadaveric shoulders. The reproducibility of the clinical sign was assessed with an interobserver and intraobserver reliability test, with calculation of the intraclass correlation coefficient (ICC). The quantified Hawkins maneuver appears to be a reproducible clinical test (median interobserver ICC, 0.9331; median intraobserver ICC, 0.9748) and creates bony contact between the greater tuberosity and the anterolateral acromion. This test enables the clinician to quantify the subacromial space.