Background: First metatarsophalangeal (MTP) joint pain is a common foot complaint which is often considered to be a consequence of altered mechanics. Foot orthoses are often prescribed to reduce 1st MTP joint pain with the aim of altering dorsiflexion at propulsion. This study explores changes in 1st MTP joint pain and kinematics following the use of foot orthoses.
Methods: The effect of modified, pre-fabricated foot orthoses (X-line®) were evaluated in thirty-two patients with 1st MTP joint pain of mechanical origin. The primary outcome was pain measured at baseline and 24 weeks using the pain subscale of the foot function index (FFI). In a small sub-group of patients (n = 9), the relationship between pain and kinematic variables was explored with and without their orthoses, using an electromagnetic motion tracking (EMT) system.
Results: A significant reduction in pain was observed between baseline (median = 48 mm) and the 24 week endpoint (median = 14.50 mm, z = -4.88, p < 0.001). In the sub-group analysis, we found no relationship between pain reduction and 1st MTP joint motion, and no significant differences were found between the 1st MTP joint maximum dorsiflexion or ankle/subtalar complex maximum eversion, with and without the orthoses.
Conclusions: This observational study demonstrated a significant decrease in 1st MTP joint pain associated with the use of foot orthoses. Change in pain was not shown to be associated with 1st MTP joint dorsiflexion nor with altered ankle/subtalar complex eversion. Further research into the effect of foot orthoses on foot function is indicated.