There are physiological factors, on the one hand, and disease factors, on the other, in the presence of calf ectropion.
Usually young children aged 2 to 6 years develop physiological calf ectropion to maintain balance in the lower limbs in order to facilitate walking. Common disease factors include rickets, abnormal cartilage development, bone trauma, etc. When these factors lead to misaligned epiphysis or bone growth in the lower limbs, calf ectropion deformity also occurs.