The influence of experience on the reliability of goniometric and visual measurement of forefoot position

Goniometric measurement of forefoot position relative to the rearfoot is a routine procedure used by rehabilitation specialists. This measurement is also frequently made by visual estimation. The influence of tester experience on the reliability of these two techniques at the forefoot is unknown. The purpose of this investigation was to directly examine the reliability of goniometric and visual estimation of forefoot position measurements when experienced and inexperienced testers perform the evaluation. Two clinicians (> or = 10 years experience) and two physical therapy students were recruited as testers. Ten subjects (20-31 years old), free from pathology, were measured. Each foot was evaluated twice with the goniometer and twice with visual estimation by each tester. Intraclass correlation coefficient (ICC) and coefficients of variation method error were used as estimates of reliability. There was no dramatic difference in the intratester or intertester reliability between experienced and inexperienced testers, regardless of the evaluation used. Estimates of intratester reliability (ICC 2,1), when using the goniometer, ranged from 0.08 to 0.78 for the experienced examiners and from 0.16 to 0.65 for the inexperienced examiners. When using visual estimation, ICC (2,1) values ranged from 0.51 to 0.76 for the experienced examiners and 0.53 to 0.57 for the inexperienced examiners. The estimate of intertester reliability [ICC (2,2)] for the goniometer was 0.38 for the experienced examiners and 0.42 for the inexperienced examiners. When using visual estimation, ICC (2,2) values were 0.81 for the experienced examiners and 0.72 for the inexperienced examiners. Although experience does not appear to influence forefoot position measurements, of the two evaluation techniques, visual estimation may be the more reliable.