Muscle force in living human beings is difficult to determine, because most methods are highly invasive. Electromyography (EMG) and joint kinematics are the most widely-used methods to assess muscle function, but are limited in their usefulness in dynamic motion. Intramuscular pressure, measured by placing a fiber optic pressure sensor into the muscle may be a new tool to bridge this gap. Recent results in the lab have shown that while IMP is a good predictor of muscle stress during isometric contractions, there is less correlation during dynamic contractions. These studies are being done in collaboration with Dr. Kenton R. Kaufman, Ph.D. from the Mayo Clinic.