Navicular Drop Test And Variability In Center Of Pressure During Single Limb Balance

The Navicular Drop Test is a controlled assessment of how the medial arch adapts to increased body weight. Navicular movement is associated with more pronated feet and soft tissue pathologies, especially in jumping athletes. The structural rigidity of the foot may contribute to the postural control strategy in active populations and provide valuable clinical insight. PURPOSE: To identify correlations between the Navicular Drop Test and Center of Pressure (CoP) time series during a single limb quiet stance task. METHODS: Collegiate female basketball players (n = 12, age: 19 ± 1 years, experience in sport: 11 ± 2 years, height: 175 ± 8 cm, mass: 70 ± 10 kg) were recruited to participate in a single data collection that included anthropometric and balance assessments. Bilateral assessments of foot anthropometrics included sitting and standing navicular heights, attention being placed on allowing for a relaxed foot posture. Subsequent 30-second balance assessments were completed on a single force plate (1000 Hz). During dominant and nondominant single-limb balance assessments, participants adopted an upright posture and were free of supportive bracing or shoes. Raw CoP data were digitally lowpass filtered and used to calculate CoP 95% Confidence Ellipse Area, Path Length, Mean Distance, and Mean Frequency. Further, explorations utilized anteroposterior and mediolateral time series to calculate Root Mean Square and Total Excursion Distances. Pearson correlation coefficients between balance metrics and the Navicular Drop Test results were calculated (α = 0.05). RESULTS: Navicular Drop Test results were positively correlated to Mediolateral Root Mean Square Distance (r = .477, p = 0.019) and 95% Confidence Ellipse Area (r = .530, p = 0.008). No other significant correlations were identified between the Navicular Drop Test and the balance metrics calculated. CONCLUSIONS: The ability to maintain a medial longitudinal arch correlates to the balance strategy utilized during a single limb balancing task. The present findings suggest that an arch that collapses more will coincide with a greater area of exploration and a greater variability in the frontal plane center of pressure trajectory.