A wireless in-shoe physical activity monitoring apparatus includes left and right shoe sensor systems. A shoe sensor system includes pressure sensing elements, an accelerometer, and a dongle that attaches to an exterior of a shoe. The includes a power source circuit, a clock circuit, a processing module, memory, wireless communication transceiver, sensor communication links, and an accelerometer communication link. The processing module samples, in accordance with a sampling signal, data from the plurality of pressure sensing element to produce foot force data and samples, in accordance with the sampling signal, data from the first accelerometer to produce three-dimensional foot data. The wireless communication transceiver transmits as outbound radio frequency (RF) signals regarding the foot force data and the foot three-dimensional data.
