Title: Measuring Lower Limb Muscle Activity and Kinematics in Variable Foot Strike Gaits
Abstract: Anterior knee pain affects roughly a quarter of the population, and many cases go untreated. Joint pain is a complex condition, but is influenced by morphology, kinematics (motion), and joint load imbalances, which are driven by muscle forces. To develop a better understanding of the interactions between kinematics and muscle activity patterns, non-invasive surface EMG sensors will be used on the lower limbs of pain-free subjects to measure muscle activation during different activities and gait patterns, including normal walking, toe-in/toe-out walking, and box jumps. Sensors are placed on the subject’s knee extensor muscles, hamstrings, dorsiflexors, and plantar flexors, which are the muscle groups that are most associated with knee loads. Data processing includes rectification, smoothing, and statistical analysis between different activities. Comparing these data will allow us to determine activities that lead to changes in surface EMG signals, and thus muscle forces, and how these changes may affect knee joint loads. We will then examine how those with no history of patellofemoral pain and those with a history of pain differ in muscle activation patterns. We hope that the data collected and subsequent analysis can help us determine how joint loads may be reduced in subjects with anterior knee pain may be reduced by gait retraining, physical therapy, or surgical interventions.