Pain and Movement Responses to Resistance Training to Muscular Failure in Patients With Patellofemoral Pain

This study aims to investigate the effect of training to muscular failure in patients with patellofemoral pain (PFP). In a cross-sectional observational design, participants with PFP will be be performing a knee exercise to voluntarily muscular failure. The participants will throughout the exercise trial report pain levels and continue until 1) not being able to perform the exercise as instructed or 2) reaching a pain level of 5/10 (which is a common threshold for acceptable pain within rehabilitation). During this trial, the participants will be filmed and a biomechanical analysis will be performed to see if/how compensatory movements occur.

Inclusion Criteria: * Patients diagnosed with PFP in only one knee by a licensed healthcare professional. * Aged 15-35 years. * A physical activity level of 3/10 or higher on the Tegner Activity Scale before the injury. Exclusion Criteria: * Any prior injury or condition with residual symptoms that may affect the results. * Current injury or condition affecting the performance of the test. * Resting pain greater than 0-1/10 on the Numeric Pain Rating Scale (NRS) and pain greater than 1-2/10 during light daily activities such as walking, sitting, standing, or climbing stairs.