Arm Squeeze Test: a new clinical test for differential diagnosis between cervical spine and shoulder disorders.

Introduction: Objective of this study is to evaluate the diagnostic values of the Arm Squeeze Test. The test consist in squeezing the middle third of the upper arm. Our hypothesis is that squeezing is responsible for pain only in patients with cervical nerve root compression from C5 to T1. Materials and methods: 1567 patients were included in this study. Diagnosis of cervical nerve root compression or shoulder disease was clinically and strumentally formulated beforer performing test. Then, patients were subdivided as follow: 903 with rotator cuff tear, 155 with shoulder adhesive capsulitis 101 with acromioclavicular(AC) joint arthropathy, 55 with calcifying tendonitis, and 48 affected by gleno-humeral arthritis. The study sample included 305 patients with cervical nerve root compression from C5 to T1 with pain irradiating to one or both shoulders. 350 healthy volounteers were recruited as controls. The test was positive when score on a VAS Scale was 3 points or higher on squeezing the middle third of the upper arm compared to AC joint and anterolateral-subacromial area. Results: The test was positive in 295/305(96,7%) of patients with cervical nerve root compression, compared to 35/903(3,87%), 3/155(1,93%), 0/101(0%), 1/55(1.81%), 4/48(8,33%) of those with rotator cuff tear, adhesive capsulitis, AC arthropaty, calcifying tendonitis and glenohumeral arthritis, respectively. A positive result was obtained in 14/350 asymptomatic subjects(4%). If cervical nerve root compression was compared to shoulder conditions, the test had sensitivity from 0.97 to 0.99 and specificity from 0.93 to 0.96. Respect to controls, sensitivity was 0.98 and specificity was 0.97. Conclusions: The Arm Squeeze Test may be useful to distinguish cervical nerve root compression from shoulder disease in case of doubtful diagnosis.