Patellofemoral pain (PFP) is characterized by anterior knee pain that worsens with joint loading during activities like squatting. This dissertation explores how chronic musculoskeletal pain affects motor planning and execution during a pain-evoking task. Motor cortex activity was monitored using electroencephalography (EEG) via the motor-related cortical potential (MRCP), a negative deflection beginning just before movement onset. The first aim developed a modified single-leg squat paradigm to isolate motor cortical activity during motor execution (ME) and motor imagery (MI) using each side. It was hypothesized that in healthy individuals, MRCPs would follow the same temporal pattern as during other complex lower extremity tasks, with ME evoking more motor cortex activity than MI, and similar cortical resources would be engaged when using each side. Results showed significant negative deflections for both ME and MI, with ME being more negative. Bayesian analysis and parametric testing indicated no significant side differences in either condition. The second aim was to compare the MRCP of involved and uninvolved knees within PFP patients and between patients and healthy individuals during the modified squat task. It was hypothesized that movements of the painful side would show reduced MRCP amplitude compared to the pain-free side and healthy individuals, indicating difficulty in motor planning and execution. The task effectively evoked PFP symptoms, with higher pain ratings on patients’ painful side. Despite this, there was no significant difference in MRCP amplitude between sides. A non-significant reduction in MRCP amplitude was observed for MI on the painful side compared to healthy individuals. Patient group variance was lower during both ME and MI of the involved side, indicating more stereotyped cortical activity. The largest effect was seen during MI between groups. Greater variance during motor preparation was observed before muscle onset on the painful side, indicating no consistent pattern of motor preparation in patients. This work validates a new MRCP measurement protocol and suggests that PFP is associated with inefficient motor preparation during painful movements and reduced cortical activity during MI of painful tasks. These findings indicate changes in motor cortex function in chronic PFP and suggest brain-based interventions for PFP are needed.