Abstract: A lateral guidance and support apparatus for a shoe fixed at its front end on a cross-country ski. The apparatus includes a rib attached to the ski which is adapted to engage a groove in the sole of the shoe having substantially the same cross-sectional configuration and area as the rib. The rib and the groove both include an anterior metatarsus support zone for supporting the metatarses of the foot and a posterior heel support zone for supporting the heel of the foot. The height of the rib and the depth of the groove are chosen such that in the anterior support zone of the metatarses the height of the rib is less than the depth of the groove. As a result, in this zone the sole is supported on the upper surface of the ski in two zones on either lateral side of the rib. In addition, the height of the rib and the depth of the groove are also chosen such that in the posterior heel support zone the height of the rib is greater than the depth of the groove.