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.
Foot and ankle surgery
The vast majority of foot and ankle conditions do not require surgical intervention. For example, several phalangeal conditions may be traced to the type of foot box used in a shoe, and a change of a shoe or shoe box may be sufficient to treat the condition. For inflammatory processes such as rheumatoid arthritis, non-steroidal anti-inflammatory drugs (NSAIDs) and disease-modifying antirheumatic drugs (DMARDS) may be used to manage or slow down the process. Orthotics, or an externally applied device used to modify the structural or functional characteristics of the neuromusculoskeletal system specifically for the foot and ankle, may be used as inserts into shoes to displace regions of the foot for more balanced, comfortable or therapeutic placements of the foot. Physical therapy may also be used to alleviate symptoms, strengthening muscles such as the gastrocnemius muscle (which in turn will pull on the heel, which will then pull on the plantar fascia, thus changing the structure and shape of the foot).