Effects of Functional Stabilization Training on Pain, Function, and Lower Extremity Biomechanics in Females with Patellofemoral Pain: A Randomized Clinical Trial.
Baldon RD, Serrao FV, Silva RS, Piva SR. J Ortho Sports Phys Ther. 2014 Feb 25. [Epub ahead of print]
Take Home Message: A rehabilitation program that uses hip and trunk strengthening with verbal feedback and proper instruction during rehab provided greater pain reduction, improved strength, and improved squatting mechanics compared with a standard rehabilitation program that was focused on quadriceps strengthening.
Patellofemoral Pain Syndrome (PFPS) is a common knee pathology that is often challenging for clinicians because there are many contributing factors. Clinicians have started to focus on proximal strengthening for patients with PFPS but there is limited evidence about whether these programs influence lower extremity biomechanics. If these programs improve lower extremity biomechanics then it may help explain how proximal strengthening programs influence pain and suggest that these programs may modify an important risk factor for PFPS. Therefore, Baldon and colleagues compared two rehabilitation programs among female individuals with PFPS to assess changes in pain, Lower Extremity Functional Scale, Global Rating of Change, single-leg triple hop distance, muscle strength, muscle endurance, and single-leg squat kinematics. The authors randomized 31 females with PFPS into two 8-week treatment groups: 1) a standard rehabilitation program that focused on quadriceps strengthening or 2) a functional stabilization program, which included hip and trunk strengthening exercises as well as verbal cues during lower extremity and trunk movements. Both groups improved in pain immediately after the intervention and at a 3-month follow up compared with prior to treatment; however, those in the functional stabilization program had greater improvements in pain. Both groups also had improvements in the Lower Extremity Functional Scale score immediately following the intervention and at the 3-month follow up. More participants in the functional stabilization group (14 out of 14 participants) perceived themselves as moderately better at the end of the intervention compared with participants in the standard rehabilitation program (12 out of 16 participants). Those in the functional stabilization group also had better hopping distance, trunk endurance, and eccentric hip abductor and knee flexor strength. Individuals in the functional stabilization group also had improved biomechanics during a single-leg squat immediately after the intervention. For example, increased hip flexion and decreased ipsilateral trunk inclination, contralateral pelvis depression, hip adduction, and knee abduction.
These findings show the value of using a functional stabilization program compared with just quadriceps strengthening programs for individuals with PFPS. The authors demonstrated that the functional stabilization program and not the standard rehabilitation program influenced a participant’s single-leg squat biomechanics. Patients with PFPS perform functional tasks with more hip adducted, knee abducted, and ipsilateral trunk inclination, which may place more pressure on the lateral patellofemoral joint. Since the functional stabilization program modified these mechanics it might indicate that trunk and gluteus medius strengthening with proper verbal cures can modify movement patterns and minimize pain and stress placed on the patellofemoral joint. What is unclear from this study is which component of the stabilization program is beneficial for improving biomechanical assessment; gluteus medius strengthening, trunk strengthening, verbal cues during exercise or a combination of the three? Future research needs to continue to examine functional deficits in the PFPS population, find the most effective components for a rehabilitation program, and how we can individualize programs. Overall, this study supports the use of functional stabilization programs over standard rehabilitation programs because it provided greater pain relief and improved biomechanics, which may decrease the high levels of recurrent rates for individuals experiencing PFPS (up to 91%).
Question for Discussion: Do you currently use hip strengthening with your patients who have PFPS? How have your long-term outcomes faired with this rehabilitation approach?
Written by: Neal Glaviano
Reviewed by: Jeffrey Driban
Baldon RD, Serrão FV, Silva RS, & Piva SR (2014). Effects of Functional Stabilization Training on Pain, Function, and Lower Extremity Biomechanics in Females With Patellofemoral Pain: A Randomized Clinical Trial. The Journal of Orthopaedic and Sports Physical Therapy PMID: 24568258