A Participant- and Assessor-blinded Superiority Randomized Controlled Trial of Custom Foot Orthoses for Chronic Metatarsalgia

Foot musculoskeletal disorders cause significant impairments and disabilities for those affected. Among the various types of foot pain, chronic metatarsalgia (CM) is the most prevalent. Metatarsalgia represents 88% of all causes of foot pain, with a prevalence of 13 to 36% in adults. It is characterized by persistent pain to one or more metatarsophalangeal joints, resulting from harm (whether of mechanical origin or not) to the anatomical structures associated with the joint, including bone, cartilage, capsule and ligaments, tendons, bursae and subcutaneous tissue, and skin. Chronic metatarsalgia significantly reduces the quality of life of those affected, physically, psychologically, and socially. Different treatment modalities are used for CM, such as stretching exercises, footwear modifications, and foot orthoses (FOs). The first-line treatment is conservative, and surgery should be considered only when conservative treatment fails. Nevertheless, there is little high-level evidence (level I) to support the efficacy of conservative treatments for CM.

The reduction of the mechanical overload under the metatarsal heads during locomotion is a fundamental aspect of CM treatment, and it strongly correlates with pain reduction. Foot orthoses are commonly used devices to reduce pain and improve function in individuals with musculoskeletal disorders. They reduce forefoot plantar pressure during locomotion in individuals with CM and redistribute plantar pressure more evenly. Metatarsal pads, a common FOs modification, effectively redistribute forefoot plantar pressure and thus reduce pain caused by excessive metatarsal loads. Adding a medial wedge to FOs (inclination in the frontal plane) further reduces forefoot peak pressure in healthy adults. While FOs tested so far are generally effective in managing CM, their effects can be inconsistent across patients, some patients did not find them effective. From a biomechanical standpoint, FOs reduce mechanical overload; however, it is crucial to determine whether they also effectively reduce pain and improve foot function. Randomized controlled trials (RCT) are considered the gold standard for evaluating treatment effectiveness and efficiently translating research findings into clinical practice. This study design will allow us to assess whether, in addition to their biomechanical effects, FOs provide clinical benefits for individuals with CM.

All details are here : https://doi.org/10.1371/journal.pone.0340905