Leg length discrepancy in marathon runners.

The incidence and degree of leg length discrepancy was studied in 35 male marathon runners. Seventy-seven percent were in their 30s or 40s. Eighteen runners had a length difference of less than 5 mm, 10 had a difference of 5 to 9 mm, and 7 had differences of 1.0 cm or greater. Four of the five runners using a lift had less than a 5-mm discrepancy. It is concluded that discrepancies of 5 to 25 mm are not necessarily a functional detriment to marathon runners, and no consistent benefits could be attributed to the use of a lift.