INTRODUCTION
Patellofemoral pain syndrome (PFPS) is a common source of knee pain in the physically active population and one that we treat at Physical Therapy First regularly. PFPS occurs more in females than males with a ratio of 2:1. This syndrome presents as pain in the anterior part of the knee, around the kneecap, and can occur on one or both sides of the body. It is commonly an overuse injury and has been linked to impairments of the quadriceps muscle. In the study Hip Strengthening Prior to Functional Exercise Reduces Pain Sooner Than Quadriceps Strengthening in Females with Patellofemoral Pain Syndrome: A Randomized Clinical Trial, the authors address the hypothesis of early proximal hip strengthening versus quadriceps strengthening for the treatment of PFPS.
METHODS
Thirty-three women with unilateral or bilateral patellar pain were included in the study and given the visual analog scale (VAS) as a pain scale and the Lower Extremity Functional Scale (LEFS) as a measure of function. Objective measures including isometric hip abduction, hip external rotation, and knee extension were taken using a hand held dynamometer. Functional strength was also assessed using an anterior step-down test for the number of repetitions in a 30 second period of time.
Participants were divided into hip or quadriceps strengthening program and performed rehabilitation exercises three times a week for four weeks in addition to a common stretching program. Both groups then performed the same exercises for weeks four through eight which focused on functional weight-bearing and balance training.
After the eight weeks of training, participants were given the VAS and LEFS and their strength was re-measured.
RESULTS
The results showed significantly less pain in the hip strengthening group compared to the quadriceps group at four weeks as reported on the VAS. Pain scores at four and eight weeks were significantly lower than baseline scores in the hip group. Scores for the quadriceps group were significantly lower at the eight-week time point but not at the four-week point compared to baseline.
Both groups significantly improved on the forward step-down test. Hip abduction strength significantly increased in the hip group from weeks zero to eight but not in the quadriceps group. Hip external rotation strength increased over the 8-week period in both groups. Knee extensor strength did not improve in either group over time.
DISCUSSION
The purpose of this study was to compare initial hip strengthening to initial quadriceps strengthening in the treatment of females with PFPS. It was hypothesized that rehabilitation initially focusing on isolated hip strengthening would result in less pain, more strength and function, and better preparation for functional exercises than initial quadriceps strengthening. While both groups experienced similar overall increased strength and function, the hip group reported less pain than the quadriceps group after the first four weeks of rehabilitation.
The most significant finding of the study was the decreased pain reported at week four in the hip strengthening group, which decreased by 43%. Both hip and quadriceps strengthening led to increased function over time as measured by the forward step-down test.
The authors found it interesting that there were no improvements in quadriceps strength in this group. The authors proposed this finding could be due to pain preventing adequate muscle activation.
LIMITATIONS
One limitation in this study includes the varying amount of pain reported by the participants; some had minimal pain with activity and others had a higher degree which severely limited their function. Additionally, the study only looked at women and was only performed for an 8-week time period so it cannot be generalized to men with this syndrome or show long term effects
CONCLUSIONS AND PTF IMPLICATIONS
The main conclusion in this article shows that focusing on a proximal hip strengthening program is more efficient in decreasing pain and increasing hip strength than quadriceps strengthening program in the treatment of PFPS.
PFPS is a diagnosis that we commonly see at Physical Therapy First and our therapists are able to create an individualized treatment program which includes proximal hip strengthening for the treatment of patellar pain.
Dolak, K., Silkman, C., Medina McKeon, J., Hosey, R., Latterman, C., Uhl, Timothy (2011). Hip Strengthening Prior to Functional Exercises Reduces Pain Sooner Than Quadriceps Strengthening in Females With Patellofemoral Pain Syndrome: A Randomized Clinical Trial. Journal of Orthopaedic & Sports Physical Therapy: Vol 41, 8: 561-570.