Measuring Lower Limb Muscle Activity and
Kinematics in Variable Foot Strike Gaits
Author:
Thomas Matsumura ’22Co-Authors:
Benjamin Wheatley, Mark SeeleyFaculty Mentor(s):
Benjamin Wheatley, Mechanical EngineeringFunding Source:
Bucknell Program for Undergraduate Research; Bucknell-Geisinger Research InitiativeAbstract
Anterior knee pain affects roughly 23% of adults and 29% of adolescents, and many cases go
untreated. Prior research has aimed to identify underlying causes of knee pain,
and while exact causes can be unknown for individuals, differences in muscle activity, gait
patterns, morphology, and loading are key contributors. To better understand links between
muscle activity and kinematics, we aimed to measure changes in surface electromyography of knee extensor muscles and others as a result of different gait patterns. A total of twenty subjects underwent surface electromyography measurements in the Bucknell motion analysis biomechanics lab and with the use of non-invasive surface EMG sensors that measure muscle activation. Specific activities and gait patterns include normal walking, toe-in/toe-out walking, heel-strike/toe strike, and normal running. Sensors were placed on the subject’s vastus medialis and lateralis, quadriceps, hamstring, and medial/lateral gastrocnemius. Following data collection, data processing included rectification, high/low pass filters, root mean square and moving envelope calculations, and normalization to maximum voluntary contraction EMG. Statistically significant patterns were identified in EMG profiles both intra-subject and between subjects, with the Vastus Medius and Vastus Lateralis showing the most variation in activation, and toe-in/toe-out walking showing the greatest activation. In several subjects, the activation profile of both the Rectus Femoris/Hamstrings and Gas Med/Gas Lat were not statistically different from themselves but were different than the Vas Med/Vas Lat ratio. The next step is to discuss clinical relevancy and how our data can inform pain prevention.