Trench foot
Trench foot can be prevented by keeping the feet clean, warm, and dry. It was also discovered in World War I that a key preventive measure was regular foot inspections; soldiers would be paired and each made responsible for the feet of the other, and they would generally apply whale oil to prevent trench foot. If left to their own devices, soldiers might neglect to take off their own boots and socks to dry their feet each day, but if it were the responsibility of another, this became less likely. Later on in the war, instances of trench foot began to decrease, probably as a result of the introduction of the aforementioned measures; of wooden duckboards to cover the muddy, wet, cold ground of the trenches; and of the increased practice of troop rotation, which kept soldiers from prolonged time at the front.
Barefoot running
The running shoe itself has also been examined as a possible cause of many injuries associated with shod running. One 1991 study found that wearers of expensive running shoes that are promoted as having special features, such as added cushioning or "pronation correction", were injured significantly more frequently than runners wearing inexpensive shoes. It has also been found that running in conventional running shoes increases stress on the knee joints up to 38%, although it is still unclear if this leads to a higher rate of heel injuries or not. One study suggests that there is no evidence that cushioning or pronation control in shoes reduces injury rates or reduces performance. It was also found that the belief that one's shoes have increased cushioning had no effect on increasing or decreasing ground reaction forces during walking. Modern running shoes can also increase joint torque at the hip, knee, and ankle, and the authors of the study even suggest that running in high heels might be better than modern running shoes. Improperly fitting shoes may also result in injuries such as a subungual hematoma – a collection of blood underneath the toenail. This may also be known as "runner's toe" or "tennis toe". However, a recent randomized controlled trial (RCT) suggested that heavier runners might be at an increased risk for injury in minimalist shoes (designed to mimic barefoot running) as compared to conventional footwear.