The Role of Cutaneous Receptors on the Dorsal Ankle joint during Locomotion
The aim of the current thesis was to explore the proprioceptive role of dorsal foot skin and its influence on the joint kinematics of gait strategies during, normal level walking (Experiment I) as well as during adaptive gait while crossing an obstacle (Experiment II). Twelve volunteer’s kinematic data were recording during walking trials for each experiment. Test conditions included sensory interventions which either reduced skin input (via topical anesthetic), visual input (via lower occlusion goggles) or simultaneously manipulated both skin and vision. Our results show that ankle control in gait relies on feedback from skin overlaying the joint. In level walking, anesthetic produced significant angular changes in the ankle and knee joints but no changes to minimal toe clearance (MTC). With the lead limb anesthetized, toe clearance (TC) while crossing the obstacle was increased. Conversely, anesthetizing the trailing limb had no effect on any joint positions or toe trajectory parameters. The acute loss of skin input in healthy young adults resulted in involvement for ankle and knee joint position sense however were perhaps corrected through alternative strategies since no changes to MTC were observed. Conversely, when faced with an obstacle increased toe trajectory effects following sensory perturbations is indicative of a less compensatory ability and emphasis to avoid foot contact. This work is the first to highlight the influence of reduced dorsal foot skin input on locomotor strategies which are commonly encountered in aging populations.