Muscle Weakness in the Empty and Full Can Tests Cannot Differentiate Rotator Cuff Tear from Cervical Spondylotic Amyotrophy: Pain Provocation is a Useful Finding

Table 3: Sensitivity and specificity for each positive sign.

	Sensitivity	Specificity	PPV	NPV	P
Muscle weakness during the ECT	77.8%	0%	45.7%	0%	0.015*
Muscle weakness during the FCT	66.7%	4.0%	42.9%	10.0%	0.008*
Pain provocation during the ECT	88.9%	96.0%	96.0%	88.9%	< 0.001*
Pain provocation during the FCT	74.1%	96.0%	95.2%	77.4%	< 0.001*

ECT, empty can test; FCT, full can test; PPV, positive predictive value; NPV, negative predictive value; *Statistically significant (P < 0.05).