Members of the Old Dominion University community and public are invited to the dissertation defense of Paige Agnew, MS, CSCS, USAW.

 

Dissertation title: ELECTROMYOGRAPHY, PROSTHETIC PROPERTIES, AND RUNNING BIOMECHANICS IN PERSONS WITH LOWER EXTREMITY AMPUTATION 

 

Location and time: Friday, April 17th from 1p-3p in HS2 1002.

 

Abstract

Lower extremity loss affects nearly 150,000 individuals in the United States yearly yielding extreme health care costs annually. Typically, prosthetic devices are prescribed for 5-8 years despite known changes to an individual’s gait as time progresses. Patients can expect to undergo approximately 8-12 weeks of gait retraining with optional maintenance sessions to improve their comfort and efficiency using a prosthesis. Although patients can be reevaluated for higher level prostheses, it is known that this process can be challenging and drawn out thus defining a need for improved assessments to meet the patients changing needs more swiftly. The purpose of this dissertation is to investigate the biomechanical demands for lower extremity prosthesis users during running. The first study aimed to synthesize peer-reviewed evidence through a systematic review of electromyography during walking and running tasks. Thirteen studies determined a significant gap in literature surrounding a) electromyography placement standards and b) standardized normalization methods, in addition to most literature identifying increased muscle activity in the non-amputated limb compared to the amputated limb. The second study explored an in-situ method for assessing prosthetic device stiffness utilizing 3-dimensional motion capture and force plate kinetics, building upon current methods that employ machine testing. Two participants volunteered for this study with two different prosthetic devices. The results of this investigation uncovered a more viscoelastic than elastic nature of the prosthesis through higher stiffness values, a pinched hysteresis curve, and higher loading rates, not found via machine testing, suggesting pertinence to implement an in-situ method. Lastly, the third study focuses on improving prosthetic prescription by determining the effect of prosthesis stiffness on running kinetics, spatiotemporal metrics and electromyography. Six participants volunteered for this investigation; five prosthetic devices were borrowed from Hopper, Inc for testing. Each participant ran on two different prostheses, one that was their prescribed stiffness, and one either higher or lower than their prescribed stiffness and recorded using 3-dimensional motion capture, electromyography and force plate kinetics. Through single subject analyses and group-wise dependent t-tests, this study found few significant differences between limb and across conditions despite differences in prescribed prosthetic stiffness. As running mechanics were more robust than expected, these findings support the need to reevaluate current manufacturer's recommendations and clinical guidelines for prescription.

 

The committee consists of:

Dr. Hunter Bennett (chair), Dr. Stacie Ringleb, and Dr. Brittany Samulski