Talus Position Correlates With Dorsiflexion Range of Motion Following a Lateral Ankle Sprain: A Cross-Sectional Study

Following an ankle sprain, clinical examination often reveals ankle dorsiflexion pain, which has been implicated as a risk factor for recurrent ankle sprains; however, the mechanism of ankle dorsiflexion pain has not been explored. Using magnetic resonance imaging (MRI), we evaluated the relationship between the limited dorsiflexion range of motion due to pain and the position of the talus. We investigated whether an anterior talofibular ligament (ATFL) tear affected ankle dorsiflexion.

We reviewed 36 medical records and MRI images of outpatients diagnosed with a lateral ankle sprain. The data recorded were weight-bearing lunge test (WBLT), talus alignment, and ATFL tear. Weight-bearing lunge test differences (WBLTD) between the affected and unaffected sides were calculated. Talus alignment was defined on MRI as the extent of anterior displacement from the posterior lip of the tibia to the nearest articular surface of the talus (distance). Spearman's rank correlation coefficient was used to analyze the relationships between WBLTD and distance. Next, we divided the patients into two groups based on the ATFL tear and compared the WBLTD and distance using the Mann-Whitney U test.

The mean and standard deviation for distance and WBLTD were 0.9 ± 0.9 and 3.5 ± 2.8, respectively. Spearman's rank correlation coefficient between distance and WBLTD was 0.48 (p = 0.003). There was no significant difference between tear or no-tear of the ATFL with WBLTD and distance, respectively.

Anterior deviation of the talus positively correlated with dorsiflexion range of motion. Our study highlighted that the talus might have an anterior deviation in the unstressed position. However, the ATFL tear's effects on talar displacement and dorsiflexion angle were unknown.