Table 2.

Modified classification of instability and impingement in the athletic shoulder [1, 2, 4]

Group	Pathology	Etiology	Pattern of Lesions
1	Primary impingement	Subacromial stenosis	Rotator cuff lesions
	No instability
2	Primary instability	Repetitive microtrauma	Labro-ligamentous lesions
	Secondary impingement		Rotator cuff lesions
			SLAP lesions
			Posterosuperior impingement
3	Primary instability	Generalized hyperlaxity	Large capsular volume
	Secondary impingement		Rotator cuff lesions
			Labral abnormalities
4	Primary instability	Acute trauma (dislocation)	Labro-ligamentous injuries
	No impingement		SLAP lesions