Reliability and validity of a new ankle electrogoniometer

Abstract

OBJECTIVES: To establish reliability, accuracy and concurrent validity of a new electrogoniometer (SG110A, Biometrics) for measuring ankle movement. METHODS: The new electrogoniometer, placed at the lateral malleolus (A-perp), was compared to a customary electrogoniometer (SG110, Biometrics), placed along the Achilles tendon (A-para). Concurrent recordings were made with motion analysis. Common dance movements were performed by 17 dancers on two days. Intraclass correlation coefficients (ICC) and standard error of measurement (SEM) were calculated for sagittal angular displacements. RESULTS: Instrument and intra-tester reliability of A-perp was high (r >or= 0.985, r >or= 0.979, respectively). Criterion and concurrent validity were also high (r >or= 0.954, r >or= 0.937). SEM ranged from 1.43 degrees to 6.99 degrees. CONCLUSIONS: The high ICC values establish acceptable reliability and validity. Subjects found A-perp more comfortable. Although both electrogoniometers are acceptable (comparable SEM) to measure extreme ankle motions, the greater comfort and durability of the new A-perp sensor is advantageous.