Forefoot and rearfoot kinematics in recreational runners with a history of tibial stress injury

There is some evidence to support the notion that those with a history of tibial stress injuries exhibit a different loading pattern compared to an uninjured population [1]. Dynamic foot function during loading may be important in determining injury risk. At the rearfoot, greater peak eversion has been reported in female runners with a history of tibial stress fracture, compared to runners without previous bony injury [2]. However, a link between peak rearfoot eversion and risk of stress fracture was not found during a prospective study on military recruits [3]. Given these contrasting findings, peak rearfoot eversion is worthy of further investigation in injured populations. Forefoot motions during gait have not been investigated previously in those with a history of tibial stress injury. Significant motion occurs between the forefoot and rearfoot during early stance [4]. The foot has been suggested to act as a twisted plate model which produces counter rotations of the forefoot with respect to the rearfoot [5]. Rearfoot eversion is accompanied by both forefoot inversion [5] and forefoot abduction [6]. These motions result in separation at the joints of the midfoot. Ligament laxity and muscle function help to govern not only the magnitude of joint separation, but also the rate of rotation. Therefore, peak joint angles and velocities might be important in determining the loading response of the foot.