The agreement and repeatability of measurements of ankle joint dorsiflexion and poplietal angle in healthy adolescents

BACKGROUND: The intra-rater repeatability and inter-rater agreement of orthopaedics measurements are important for estimating injury risk and appropriate treatment. In clinical practice, it is often unavoidable to trust the measurements of other health professionals. METHODS: This study tested the agreement and repeatability of measurements of the dorsiflexion of the foot, dorsiflexion with 90-degrees knee flexion, and popliteal angle test in healthy adolescents performed twice by three raters differing in clinical experience. Three raters, i.e., an orthopaedics specialist (16 years of experience), a resident medical doctor in orthopaedics (4 years of experience), and a physiotherapy student (1 year of experience) measured the ankle joint dorsiflexion and the popliteal angle in 142 healthy adolescent subjects. RESULTS: The student outperformed more experienced raters by displaying good repeatability for all the evaluated parameters. The orthopaedics specialist failed to replicate the measurements of the left ankle joint passive dorsiflexion and the left popliteal angle. The medical resident in orthopaedics displayed a lack of repeatability in evaluating the right ankle joint dorsiflexion with the knee joint bent. Kendall’s W value for all parameters ranged 0.66–0.78, indicating a good inter-rater agreement. CONCLUSIONS: The study highlights that measurements of the ankle joint dorsiflexion and popliteal angle test by different health professionals can generally be trusted. It indicates that novice health professionals could potentially evaluate such parameters in healthy subjects without a quality loss.