A system, method and footwear sensor unit a footwear sensor unit removably attachable to footwear, the footwear sensor unit including: an Inertial Measurement Unit (IMU) including a 3-axis accelerometer and a 3-axis gyroscope, the IMU adapted to gather sensor data of detected movements of the footwear； and a storage device in electronic communication with the IMU, the storage device for storing the sensor data； and a communications module in electronic communication with the storage device, the communication module configured to transmit data to an external computing device.
