Abstract
BACKGROUND: Jones fracture of the fifth metatarsal is a common overuse injury in soccer players and may cause long-term absence from training. Despite the increasing population of female soccer players, the incidence and risk factors of Jones fracture, including plantar pressure characteristics, among these players have not been clarified. PURPOSE: To investigate the association between Jones fracture and plantar pressure distribution during running and musculoskeletal characteristics in young female soccer players. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: A cohort of female soccer players who played competitively in high school and college teams, aged 15 to 21 years, were followed over a year. All players underwent physical examination at baseline, which included anthropometric measurements, body composition evaluation, joint laxity, double- and single-leg balance measurements, lower limb muscle flexibility, and hip internal rotation angle, foot arch height ratio, and dynamic foot pressure measurements during running. Foot pressure distribution was analyzed by measuring the sum and maximal pressure of 10 areas, and the loading rates of the lateral toes, lateral metatarsal, lateral forefoot, forefoot/rearfoot ratio, and lateral/medial ratio were defined. All these measurements were compared between players who had Jones fracture (Jones group) and players without injuries (control [Con] group). RESULTS: A total of 105 players were included, and 4 players (6 feet) were included in the Jones group. Hamstring flexibility was significantly lower in the Jones group than in the Con group. The Jones group presented a higher forefoot/rearfoot ratio of the maximal pressures, lower sum pressure in the lateral heel, higher maximal pressure in the lateral toes, and higher maximal pressure in the first to third metatarsals than the Con group. No significant differences were found between the 2 groups regarding other factors. CONCLUSION: Foot plantar pressure with a higher forefoot/rearfoot ratio, less loading on the heel, and higher pressure on the lateral toes and medial metatarsals during running were associated with Jones fracture in female soccer players. Lower hamstring flexibility was identified as a risk factor for Jones fracture, which has not been reported in male soccer players.