Relationship Between the Angle of the Foot Arch and the Length of the Foot

Aim: Foot morphology and anthropometry are known to be associated with biomechanical measurements of foot. The medial longitudinal arch (MLA), which is the main arch contributing to the foot morphology, provides an elastic connection between the forefoot and hindfoot. Problems and alignment disorders, specifically caused by MLA, such as pes cavus and pes planus, ultimately affect the functions of the muscles and joints of the lower extremity. In this study, we aimed to investigate the relation between MLA and bony-length of foot by making measurements on radiographs. Material and Method: 212 (106 right and 106 left sides) weightbearing lateral x-ray images of 106 patients (36 females, 70 males) aged between 18-80 (m:18-75, f:18-80) were evaluated. Images of the patients aged under 18 or above 80, with any sign of trauma or surgery, space-occupying lesion of foot or deformity of foot bones were excluded. The maximal bony-length of the foot and in order to evaluate the medial longitudinal arch (MLA) the angle between the calcaneus and the 1st metatarsal bone and calcaneal inclination angle were measured on the x-ray images. The results were evaluated statistically. Results: The mean bony-length of the foot was measured as 237.5 mm (216.5-256.7 mm) in females and 264.1 mm (205.0-293.6 mm) in males. The mean respective calcaneal inclination angle and the angle between the calcaneus and the 1st metatarsal bone were measured as 18.2o (2.7o-31.4o) and 140.2o (119.5o-159.8o). In both gender there was a significant correlation between the bony-length of foot and angles (p<0.01 for both angles). There was also found a significant correlation between calcaneal inclination angle and the angle between the calcaneus and the 1st metatarsal bone (p<0.01). Conclusion: MLA, known to be effective on functions such as balance, walking, standing on one or two feet, jumping and squatting, which are associated with foot morphology, was found to be related to foot length in both gender. This results in a prediction of predisposition to the pes planus in people with large feet