Internal Impingement of the Shoulder: A Risk of False Positive Test Outcomes in External Impingement Tests?

Table 1

Mechanical contact between the supraspinatus and the glenoid labrum (in %).

Mechanical contact	Shoulder position
	90° abduction + 15° internal rotation “horizontal impingement test”	170° abduction “Neer test”	Neutral position	90° flexion, + 15° internal rotation “Hawkins test”
No impingement	5.4	18.9	100.0	51.4
Impingement without deformation	86.5	67.6	0	37.8
Impingement with deformation	8.1	13.5	0	10.8
Overall	100.0	100.0	100.0	100.0