Understanding Patellofemoral Syndrome

Knee pain can be a debilitating problem, especially when an individual is not involved with a traumatic event or accident. One condition that I have seen more frequently in my practice as a physical therapist over the years is called patellofemoral syndrome (PFS).

There are several reasons and contributing factors that per the research support why there is an increase of prevalence of PFS in the clinic. This article will delve into discussing what patellofemoral syndrome is, contributing factors, typical treatment and post-therapy, evidence-based training strategies with rationale.

Clinical Presentation & Pathology

PFS typically affects young women more than men 12-40 years of age, who often describe pain as diffuse, achy throughout the front of the knee, and global in nature. People with PFS will complain of pain with loading activities (such as running, jumping, descending stairs and prolonged activities). Rest, unloading or decreasing the load to the quadriceps typically provides relief. PFS is pain that develops over time in which the individual will usually not have trauma associated with the pain. Because there is typically no trauma involved, the pathology is uncertain.

How PFS Develops & Contributing Factors

The causes of patellofemoral syndrome are not clear. However, there have been several contributing factors that have been discussed in the medical field and in research. Some postulate that the development of patellofemoral pain is caused by abnormal tracking of the patella within the femoral trochlear groove.¹ This leads to increased stress on the patellofemoral joint. Muscle imbalances particularly between the quadriceps, hamstrings and iliotibial band has been examined, lack of flexibility, particularly the hip flexors, ITB and quadriceps and increased q-angle. Decreased strength of the hamstrings vs. quadriceps and deviations in patellar position are also factors.² There has been previous research conducted (Crossley et al 2001) that hypothesized that training the vastus medialis oblique (VMO), accompanied by taping and manual therapy, would be an effective intervention. The results throughout the literature are inconsistent and some research suggests that the VMO could only be recruited truly during mini squats and isometric hip abduction.

What Does the Research Say?

Several studies have demonstrated a correlation between decreased hip strength and PFS (Bolgla et al 2005, Dierks et al 2008, Boiling et al 2009). Females with PFS demonstrated greater hip adduction during running, hopping and single leg activities. A systematic review of five studies found that abduction and external rotation strength was weaker than in control groups. Women also have a higher incidence of PFS then men and the incidence rate of 25% to 43% have been reported in sports medicine.³ A study by Prims & Van der Wurff (2007) examined hip strength in females with patellofemoral pain and those without patellofemoral pain. The study yielded strong evidence for deficits in hip external rotation, abduction and hip extension strength. The conclusion was that females with patellofemoral pain syndrome demonstrate a decrease in hip abduction and external strength.⁴

Treatment

Physical examination is typically brief and is accomplished by the physician examining ROM, palpating and brief tests to rule out other pathologies. Radiographs may be ordered at the discretion of the physician and an individual’s presentation. Typically individuals are instructed by physicians to take NSAID’s for inflammation, modify activity level and pursue physical therapy.

Physiotherapy treatment consists of manual therapy that addresses muscle imbalances, stretching, taping to improve patellar-tracking and reducing pain. Restoring proper patella mobility prior to promoting stability is vital with those afflicted with PFS. It is imperative that the patella track properly in the trochlear groove and perform its specific function, which is to transmit force above to below the knee joint.

Massage and stretching tight phasic muscles(ITB, quadriceps, hip flexors and TFL) is very effective. Functional strengthening targets the weaker glute medius, glute maximus and hamstrings and also strengthens the lumbo-pelvic junction initially, statically and then dynamically.

Post-therapy Training Strategies

Decrease load to quadriceps, stretching hip flexors, ITB and hamstrings, balance strengthening of hamstrings vs. quadriceps, education on shoes, cross training via swimming and altering running surfaces (if client runs). The emphasis needs to be placed on strengthening the weaker (phasic) hip abductors, specifically, the glute medius and glute minimus.

Diagonal lunges using medicine balls or holding onto tubing is very effective. While reverse lunges will target the glute maximus, modifications can be made to progress towards making the exercise more dynamic. This can be done with placing one foot standing on a half roll or unstable surface or using a free motion cable machine and performing the movement.

Exercises

Figure 1. Hip flexor stretch (keeping knee behind toe and not letting the trailing knee touch the ground)	Figure 2. Hamstring stretch

Figure 3. ITB Stretches

Figure 4. Hamstring curls w/physio ball	Figure 5. Trunk rotation w/diagonal lunge

Figure 6. In-place partial lunge w/diagonal cable rotation

Summary

When a client has patellofemoral syndrome, understanding the pathology and limitations facing the client is an important first step prior to exercise prescription. Awareness is key. Exercise prescription should be specific and personalized taking into account the age, severity of pain or history and the client’s goals. Train the client in single planes progressing to multi-planes targeting their “weak links” based on the science, can preventing future injuries from occurring and helping your client not only achieve their goals, but coming back for more!

References

1. Crossley, K, et al. 2002, ‘Physical Therapy for Patellofemoral Pain: A Randomized Double-Blinded, Placebo-Controlled Trial’, The American Journal of Sports, vol. 30, no. 6, pp. 857-864.

2. Meira, Erik, P, & Brumitt, Jason, 2011, ‘Influence of Hip on Patients with Patellofemoral Pain Syndrome: A Systematic Review’, Sports Health: A multidisciplinary Approach, vol 3. Issue, 5, pp. 455-463.

3. Lankhorst, 2012. ‘Risk factors for patellofemoral pain syndrome: a systematic review’, The journal of orthopaedic and sports physical therapy, 0190-6011, vol. 42, Issue 2, p 81

4. Prins, Maarten R & van der Wurff, Peter, 2009, Females with patellofemoral pain syndrome have weak hip muscles: a systematic review’, Australian Journal of Physiotherapy, vol. 55, Issue 1, p. 9.

General References

Bolgla, et al, 2008, ‘Hip strength and hip and knee kinematics during stair descent in females with and without patellofemoral pain syndrome’, Journal of Orthopedic Physical Therapy, vol. 38, pp. 12-18.

Boiling et al, 2009, ‘A prospective investigation of biomechanical risk factors for patellofemoral syndrome: the joint undertaking to monitor and prevent ACL injury’, American Journal of Sports Medicine, vol. 37, pp. 2108-2116.

Dierks et al, 2008, ‘Proximal and distal influences on hip and knee kinematics in runners with patellofemoral pain during a prolonged run’, Journal of Orthopedic Physical Therapy, vol. 38, pp. 448-456.

About the Author

Chris Gellert, PT, MMusc & Sportsphysio, MPT, CSCS, CPT is the President of Pinnacle Training & Consulting Systems. Gellert offers educational workshops on human movement, home study courses on human movement, and consulting services. As a clinician, author, presenter, with extensive experience having treated and worked with individuals’ of all ages with various spinal injuries, post surgical conditions, traumatic and sport specific injuries in industrial rehabilitation, outpatient and private practice settings. For more information, contact www.pinnacle-tcs.com or email him at ptcg1999@verizon.net.