Twenty children (mean age 9 years (SD2.3)) performed five running trials at a self-selected velocity barefoot and wearing school shoes (Daytona, Clarks) in a random order. A 14 camera 200Hz motion analysis system (EVaRT5.0, MAC) was used to calculate marker trajectories. Markers were attached to the right leg and a cluster wand was attached to the calcaneus through a window in the shoe. A standing reference trial was used to embed segment axes and then calculate ankle joint complex motion. Force plate data were collected at 1000Hz (Kistler™). Data were normalised to the stance phase and sub-phases partitioned from the anterior/posterior force data as: loading (initial-contact – maximum-negative force); mid-stance (maximum-negative force – zero) and propulsion (positive force – toe-off).