Navicular Angle Method in Foot Arch Measurement: 1298

Numerous methods have been developed to evaluate foot arch, including Feiss' line, navicular drop index (NDI), navicular arch index, foot print, and foot pressure. Radiological measurement is considered to be the most precise method. However, radiological measurement is a complicated procedure, requiring expensive equipment that is often not readily available. PURPOSE: The purpose of this study was to compare the outcomes of navicular angle (NA) method and NDI to determine the efficacy of NA. METHODS: Sixty children participated in this study (8.8 ± 0.3 yrs, 25.9 ± 3.9 kg, 128.7 ± 3.6 cm). The bilateral non-weight bearing NDI in a sitting position and the even-weight bearing NDI in a standing position were measured. The bilateral non-weight bearing and even-weight bearing NA were also measured by a goniometer which defined the angle between the medial malleolus, navicular, and 1st metatarsal head. All examination were performed by teachers and physical therapists (PT). RESULTS: High reliability was observed for NA (r=0.98, r2=0.96, CV=0.10, p< 0.01) and NDI (r=0.97, r2=0.94, CV=0.11, p< 0.01). The correlation between NA and NDI was also high (r = 0.94, r2=0.89, p< 0.01). The intra-rater reliability in PT, NA (r=0.981, p<0.01) was higher than NDI (r=0.974, p<0.01). The intra-rater reliability in teachers, NA (r=0.950, p<0.05) was also higher than NDI (r=0.574, p=0.28). The inter-rater reliability of NA in PT and teacher was high (r=0.982, p<0.05). The correlation coefficient was high for PT in NA and X-ray (r=0.714, p=0.21). CONCLUSION: Navicular angle (NA) may be an effective tool for measuring foot arch, because it requires less equipment and is more easily available.