Morphofunctional Characteristics of the Foot and Ankle in Competitive Swimmers and Their Association with Muscle Pain

The aim of this study was to analyze the joint characteristics of the foot and ankle in competitive swimmers aged 16–18 and 19–24 years and their relationship with the presence of muscle pain during swimming. A total of 74 swimmers were evaluated: 38 ‘junior’ (16–18 years) and 36 ‘senior’ (19–24 years). The following parameters were recorded: ankle dorsiflexion, rearfoot mobility, first metatarsophalangeal dorsiflexion, presence of hallux valgus, foot posture, first ray mobility, arch height, and plantar pressure. Additionally, the frequency and location of muscle pain in the triceps surae were analyzed. A cluster analysis was performed to identify variables that differentiated both groups. Ankle dorsiflexion was limited in both groups, with a greater restriction observed in adults (p < 0.001 with an extended knee; p < 0.014 with a flexed knee). The predominant foot type was the cavus foot. The most common pain was localized in the triceps surae, followed by the plantar musculature, with no significant differences between groups. Swimmers exhibited gastrocnemius shortening, which could limit ankle dorsiflexion and contribute to the onset of muscle pain in the leg and foot. These findings suggest the importance of incorporating lower limb flexibility strategies into the training of competitive swimmers.