First ray model comparing normal and hallux valgus feet

Hallux valgus has been reported as one of the most common foot problems. Besides its negative impact on quality of life, it also increases the risk of falling in elderly patients and imposes additional health risks on patients with diabetic or neuropathic feet. Pathoanatomy, pathomechanics, and hypermobility studies have been conducted to evaluate the features of hallux valgus. However, hallux valgus is not yet well understood, and this is reflected by the ineffectiveness of current treatments, complications, and recurrence rates. The current study constructed first ray finite element (FE) models of a normal foot and a hallux valgus foot to examine the sole effect of extrinsic loading on the bony structure. The model showed that loading at initial push-off could lead to metatarsus primus varus and hallux abductor valgus. The hallux valgus foot also showed impaired loading transfer from the distal phalanx, which could hinder the windlass mechanism. This result showed that extrinsic loading could predispose the patient to the risk of developing hallux valgus and the intrinsic stabilization structure, such as ligaments and muscles, could be important in preventing the development of hallux valgus.