Purpose: Identify patients who likely have subacromial impingement based on specific physical examination findings.
Rule:
1. Positive Hawkins-Kennedy Test
2. Painful Arc Sign
3. Infraspinatus Manual Muscle Test
| Item | 2 + variables | 3 variables |
| SN | ||
| SP | ||
| +LR | 5.03 | 10.6 |
| -LR | ||
| PPV | 90% | 95% |
| NPV |
SN = sensitivity – ‘SnOut’ helps rule out a disease (higher number is better – >0.9 is excellent)
SP = Specificity – ‘SpIn’ helps rule in a disease (higher number is better – greater than 0.90 is excellent))
+LR = positive likelihood ratio – ratio of positive test results in a patients with the pathology (true positives) higher number is better (> 10 is excellent)
-LR = negative likelihood ratio – ratio of negative test results in a patients with the pathology (false negatives) lower number is better (< 0.1 is excellent)
PPV = positive predictive value – percentage of patients who both test positive & have the disease (true positives)
NPV = negative predictive value – percentage of patients who both test negative & do not have disease (true negatives)
References:
1. Park HB, et al. Diagnostic accuracy of clinical tests for the different degrees of subacromial impingement syndrome. J Bone Joint Surg Am. 2005; 87(7): 1446-55.
