Increased tripping frequency and the associated risk of falling is an international health problem in older adult populations. The average distance between the toe and the ground surface is approximately 1.3cm at the event where the toe reaches a minimum clearance height during leg swing of walking (Winter 1991, Begg et al. 2007). Little is known about how the lower limbs are controlled and coordinated to perform safe (risk-averse) toe-to-ground clearance. This thesis investigates the kinematic interactions of the lower limbs during unperturbed walking with a specific emphasis on examining the cooperative interactions of the stance and swing limb.