Comparison of Three Approaches of Electrode Placement to Detect Changes in Motor Evoked Potentials During Spine Surgery

Inclusion Criteria: * Patients must be ≥18 years of age * Patients must be undergoing thoracic or lumbar spine surgery where quadriceps MEP recording would be the standard of care * Patients should have normal preoperative quadriceps strength * Patients are capable of understanding the informed consent and have signed the informed consent document prior to any study-specific screening procedures or evaluations being performed Exclusion Criteria: * Patients with ongoing psychiatric concerns would be excluded. * Patients who are non-English speakers.