The effectiveness of an innovative Hallux Valgus sock on dysfunction of the 1st Ray and Hallux Abducto-valgus progression

Abstract

Hallux Abducto Valgus (HAV) is a progressive structural deformity of the first metatarsophalangeal joint which results in the lateral deviation of the hallux, and also can lead to changes in foot biomechanics, chronic pain, decreased mobility, difficulty in footwear fitting, and diminished quality of life. With a high global prevalence, especially in older adults and females, HAV lacks a consensus on an effective form of conservative treatment, and many acute and chronic situations of HAV involved surgery as the conventional treatment. Surgery in itself can create complications and risk for the patient, therefore the justification of an effective non-invasive treatment approach is both clinically and cost effective. The aim of this PhD study was to explore, assess, and test an innovative non-invasive therapeutic device; an ergonomically designed Hallux Valgus (HV) sock with a biomechanical corrective effect to relieve symptoms and restore function. The study was undertaken in four phases. Phase I entailed a full systematic review of non-surgical treatments for HAV. The systematic review involved determining clinical effectiveness, methodological quality, and biomechanical rationale of various interventions, including orthotic devices, physical therapy, footwear modifications, and bracing methods. It also aimed to assess the long-term outcomes and potential risks associated with each treatment modality, providing a comprehensive analysis of their effectiveness in halting or reversing the progression of hallux valgus.. The review found no close similarity across studies, substantial variability in outcomes, and limited high-quality evidence showing long term effectiveness for non-surgical approaches – signifying a clinical need to develop and conduct clinical trials. Phase II focused on preliminary biomechanical evaluation of the HV sock with a series of laboratory-based pilot studies. Particularly, surface electromyography (EMG) assessed muscle activation patterns, adductor hallucis, while plantar pressure mapping evaluated changes in forefoot pressure distribution and the first ray alignment while performing dynamic tasks. The studies provided evidence of a tangible mediation by reducing medial deviation of the first metatarsal, and increasing optimal loading patterns throughout the gait with the HV sock. Phase III involved a randomized controlled clinical trial with 100 participants diagnosed with mild to moderate HAV. Participants were randomly assigned to either conservative podiatric care (control group) or conservative podiatric care plus daily use of the HV sock (intervention group) during the trial of six months. Significant outcome measures included the change in HAV angle (clinically), foot function (Foot Function Index), pain intensity (Visual Analogue Scale), and patients’ quality of life (Manchester-Oxford Foot Questionnaire). Using mixed linear model and statistical tests, clinically and statistically significant improvement was demonstrated in all outcome measures in the intervention group by using eleven months with the HV sock, including a change in HAV angle that significantly exceeded established minimal clinically important difference thresholds than control group. [...]