Human Locomotion

Harutaichun P, Vongsirinavarat M, Pakpacorn P, et al. Can orthotic wedges change the lower-extremity and multi-segment foot kinematics during gait in people with plantar fasciitis? Gait & Posture 2022;97:174-183.

Monthly Research Articles

Plantar fasciitis is a common overuse syndrome that can take years to recover from. The authors of this paper theorized that you could effectively manage chronic plantar fasciitis by incorporating a 2-piece varus posting system placed beneath the patient’s insoles. The varus posts were made from solid rubber with a thin fabric cover and were available in 3 sizes depending on the person’s foot size. The authors incorporated various combinations of 3°, 6°, and 8° angled wedges and then measured three-dimensional motion in the lower extremity as subjects walked over a force plate.

Upon completion of the biomechanical analysis, the authors noted that the varus wedges placed beneath the rearfoot and forefoot reduced the relative length of the planter fascia and decreased upward motion of the great toe during propulsion. When large forefoot wedges were used, there was a significant reduction in peak knee internal rotation, decreased forefoot abduction, and decreased rearfoot eversion during contact. The reduced range of forefoot abduction with the forefoot varus posts could significantly reduce strain in the planter fascia, making it an inexpensive and effective treatment intervention for this common problem.

This paper is significant, not just because the 2-piece varus posting system so effectively reduced strain in the planter fascia, but because these wedges reduced range of motion in the 1st metatarsophalangeal joint, while simultaneously lessening the overall range of internal tibial rotation. The clinical implications are obvious: patients with hallux rigidus and/or hallux abductovalgus would benefit from reduced stress on the 1st MTP, while athletes with patellar tendinopathy, and/or meniscus injuries might benefit from a reduced range of internal tibial rotation. This research proves that a simple 2-piece varus posting system can effectively alter movement in the lower extremity at a fraction of the price of custom orthotics. A more detailed discussion of the benefits of a 2-piece posting system are described in the Peel and Stick Varus Posts article on this site.