Effectiveness of footwear and foot orthoses in reducing medial metatarsophalangeal joint pressure in women with hallux valgus

Background: Hallux valgus is a common condition where the subluxation of the first metatarsophalangeal joint and lateral deviation of the hallux at the interphalangeal joint creates difficulty with footwear fit. Footwear and foot orthoses are commonly prescribed nonsurgical treatments for hallux valgus. Research question: Do extra-width footwear and foot orthoses influence peak pressure at the medial aspect of the metatarsophalangeal and interphalangeal joints in women with hallux valgus? Methods: Community-dwelling women with symptomatic hallux valgus underwent gait testing when wearing their own shoes and when wearing extra-width footwear fitted with three-quarter length, arch-contouring prefabricated foot orthoses. Peak pressure (kPa) on the medial aspect of the metatarsophalangeal and medial interphalangeal joints and on the plantar surface of the foot (hallux, lesser toes, metatarsophalangeal joint 1, metatarsophalangeal joints 2-5, midfoot and heel) were measured using the novel pedar (R)-X system with the pedar (R) pad and pedar (R) insole, respectively (Novel, GmbH, Munich, Germany). Paired samples t-tests were used to calculate the differences between the two conditions, and the magnitude of observed differences was calculated using Cohen's d. Results: We tested 28 participants (aged 44-80 years, mean 60.7, standard deviation 10.7). Compared to their own footwear, wearing the intervention footwear and orthoses was associated with a statistically significant decrease in pressure on the medial aspect of the metatarsophalangeal joint (58.3 +/- 32.8 versus 42.6 +/- 32.8, p=0.026, d=0.49), increased pressure under the midfoot (70.7 +/- 25.7 versus 78.7 +/- 23.6, p=0.029, d=0.33) and decreased pressure underneath the heel (137.3 +/- 39.0 versus 121.3 +/- 34.8, p=0.019, d=0.45). Significance: The intervention footwear and orthoses significantly decreased peak pressure on the medial aspect of the first metatarsophalangeal joint but had no significant effect on the interphalangeal joint. Further studies are required to determine whether these changes are associated with improvements in symptoms associated with hallux valgus.