Phalen’s test. Classic or modern?

Abstract

Objective: to compare the sensitivity and specificity of the classic and modified Phalen test and to give recommendations on the expediency of using the tests in the diagnosis of carpal tunnel syndrome (CTS).

Materials and methods. The experimental group included 21 women (15 right and 14 left hands) with signs of idiopathic carpal tunnel syndrome. The control group also included 21 women (15 right and 14 left hands) without characteristic clinical manifestations of carpal tunnel syndrome. The mean age of the participants in both groups averaged 52 years.

Twenty-one women in the experimental and, respectively, in the control groups were randomized to perform both the classical and modified Phalen tests on 29 hands. In the classic Phalen test, the subject places her flexed elbows on the table so that the forearms are in a vertical position. The hands under the action of gravity are flexed as far as possible, the fingers remain in extension. When performing the modified Phalen test, the subject is asked to connect the dorsal surfaces of both hands, relax the upper limbs and, while maintaining this relaxed state, lower the elbows below the horizontal line.

Results. The sensitivity of the classic Phalen test was 93%, and that of the modified test was 96%. The specificity of the classical Phalen test was 96%, modified - 93%. The positive predictive value (PPV) of the classic Phalen test was 96%, the negative predictive value (NPV) was 93%. The PPV and NPV of the modified test were 93% and 96%, respectively.

Conclusion. The sensitivity of the classic Phalen test (93%) was slightly lower than the sensitivity of the modified test (96%), and the specificity of the classic test (96%) was higher than that of the modified test (93%). Due to high specificity and sensitivity, both tests have significant diagnostic value and can be successfully used in the diagnosis of carpal tunnel syndrome.