Strength or Power Training for Patellofemoral Pain

The objective of this study is to compare a novel 6-week strength training rehabilitation incorporating power exercises (STRIPE) program to a standard of care (SOC) program on short-term and long-term pain, subjective function, patellofemoral pain recurrence rates, and secondary outcomes (hip abduction and extension rate of torque development and single-leg squat kinematics). We hypothesize that participants with patellofemoral pain who complete the STRIPE program will have 1) decreased pain, 2) improved subjective function, 3) reduced patellofemoral pain recurrence rates, 4a) improved hip abduction/extension rate of torque development, and 4b) decreased hip adduction and pelvic drop during a single leg squat compared to participants who complete a SOC rehabilitation program.

The proposed study will compare strength-based exercises, which is the standard of care (SOC), that target the hip abductors, hip extensors, lumbo-pelvic, and quadriceps muscles, to a strength training program that utilized power-based exercises (Strength Training Rehabilitation Incorporating Power Exercises \[STRIPE\]). Individuals with patellofemoral pain, both within the military and general population, present with long-term pain, decreased subjective function, and high recurrence rates. Our primary outcomes are to determine intervention success with self-reported knee pain, measured by the visual analog scale, subjective function, measured by the anterior knee pain scale, and recurrence rates. Recent evidence suggests that two in every three individuals with patellofemoral pain report symptoms up to two years after seeking care, therefore we will assess patellofemoral pain recurrence rates for two years. Additionally, the proposed interventions target gluteal muscle function, supporting our selection of secondary outcome variables. We will assess rate of torque development, as power-based exercises are recommended to improve muscle capacity, of both the targeted gluteus medius and gluteus maximus. We will also assess frontal plane kinematics, as the gluteal muscles are responsible for controlling pelvic and hip motion during functional tasks.

Inclusion Criteria: * Participants to be between the ages of 18-40 years old. * Insidious onset of symptoms greater than 3 months. * Worst pain in the previous month of 3/10 with two of the following tasks: prolonged sitting, jumping, squatting, kneeling, running, and stair ambulation. Exclusion Criteria: * Other forms of anterior knee pain (Osgood-Schlatter, tendon pain, bursitis, etc.). * History of lower extremity surgery. * History of patella subluxation, meniscal injury or ligamentous instability. * History of referred pain from the lumbar spine.