Y-Balance Test performance for predicting plantar fasciitis in male recreational marathon runners: a prospective cohort study.

Background: Plantar fasciitis (PF) is the third most common type of running-related overuse injury. The purpose of this study was to investigate whether the performance of the Y-balance test (YBT) could predict PF development in male recreational marathon runners.

Methods: One hundred and seventy-two male recreational marathon runners underwent the YBT and were then tracked for PF development during a 3-month period. Twelve participants developed PF. Their baseline data were compared to those of runners who remained uninjured.

Results: During the 3-month follow-up, 7% of the marathon runners sustained PF. The posterolateral interlimb asymmetry observed during the YBT (YBT-PL) was significantly greater in injured runners than in uninjured runners (OR=1.183; 95% CI: 1.050-1.333; P=0.006) and was significantly correlated with PF development. Moreover, the area under the receiver operating characteristic (ROC) curves of the YBT-PL interlimb asymmetry was 0.779 (95% CI: 0.646-0.913; P=0.001).

Conclusions: YBT-PL interlimb asymmetry was associated with a greater likelihood of developing PF, and YBT-PL interlimb asymmetry greater than 4.5 cm was a strong risk factor for the development of PF in male recreational marathon runners. For every 1-cm increase in the interlimb asymmetry of YBT-PL, the risk of developing PF increased 1.183-fold. Practitioners should consider improving interlimb asymmetry as an injury prevention and treatment strategy.