This is the fancy name for clubfoot.
In this congenital disorder, the foot is turned inward (inversion) and in plantar flexion. There may be a high arched foot as well.
Sometimes caused by intrauterine compression (possibly from oligohydramnios). There is some genetic associations and it can run in families. Incidence in males is higher than in females.
Treatment is via manipulation, casting and surgery (when the first two fail). Even with successful treatment, the affected foot (if unilateral) ends up 1-2 sizes smaller than the other foot and the calf muscles end up shorter resulting in a cosmetic problem.