Cold-weather warfare
Trench foot is a medical condition caused by prolonged exposure of the feet to damp, unsanitary, and cold conditions at temperatures as warm as for as few as 13 hours. Exposure to these environmental conditions causes deterioration and destruction of the capillaries and leads to morbidity of the surrounding flesh. Affected feet may become numb, affected by erythema (turning red) or cyanosis (turning blue) as a result of poor blood supply, and may begin emanating a decaying odour if the early stages of necrosis (tissue death) set in. As the condition worsens, feet may also begin to swell. Advanced trench foot often involves blisters and open sores, which lead to fungal infections. If left untreated, trench foot usually results in gangrene, which may require amputation. If trench foot is treated properly, complete recovery is normal, though it is marked by severe short-term pain when feeling returns. Trench foot affected tens of thousands of soldiers engaged in trench warfare in World War I. Keeping feet warm and dry, or at least changing into warm and dry replacement footgear, is the best way to avoid trench foot.
Ponseti method
1. The calcaneal internal rotation (adduction) and plantar flexion is the key deformity. The foot is adducted and plantar-flexed at the subtalar joint, and the goal is to abduct the foot and dorsiflex it. In order to achieve correction of the clubfoot, the calcaneus should be allowed to rotate freely under the talus bone, which also is free to rotate in the ankle mortise. The correction takes place through the normal arc of the subtalar joint. This is achieved by placing the index finger of the operator on the medial malleolus to stabilize the leg and levering on the thumb placed on the lateral aspect head of the talus while abducting the forefoot in supination. Forcible attempts at correcting the heel varus by abducting the forefoot while applying counter pressure at the calcaneocuboid joint prevents the calcaneus from abducting and therefore everting.