Hammertoes, claw toes and mallet toes are the most common toe deformities, as of 2015, notes Oakland Orthopaedic Surgeons. These deformities can lead to problems with the alignment of the hips and knees, as well as the alignment of the bones, muscles and joints in the feet.
Hammertoe is when the toe curls at the middle joint, and it most commonly occurs in the second toe, states Oakland Orthopaedic Surgeons. Bunions, which are bony outgrowths at the side base of the big toe, often occur along with hammertoes. Claw toes are when toes curl up near the ball of the foot, then down at the middle or end joints. People whose toes curl at the upper joint suffer from mallet toe.