1. Sixty patients with typical march fracture are compared with a control group of sixty patients without march fracture. Both undertook the same 300-mile march with the Mars Task Force through rough terrain in Burma.
2. No significant differences between the two groups were noted in age, height, weight, weight of the load carried, previous occupation, family history of foot trouble, and type of shoe worn.
3. The incidence of previous foot complaints, pes planus, ankle valgus, and a relatively short first metatarsal was greater in the march fracture group.
4. The intensity of preliminary foot conditioning was the most significant difference between the two groups.
5. March fracture occurs in a structurally inadequate and improperly conditioned foot as a result of functional overloading. We believe inadequate conditioning was chiefly responsible for the high incidence of fracture in the group reported.