Patello-femoral Pain Syndrome (PFPS), a common cause of anterior knee pain, is successfully treated in over 2/3 of patients through rehabilitation protocols designed to reduce pain and return function to the individual (Waryasz & McDermott, 2008). Applying preventive medicine strategies, the majority of cases of PFPS may be avoided if a pre-diagnosis can be made by clinician or certified athletic trainer testing the current researched potential risk factors during a Preparticipation Screening Evaluation (PPSE)
(Waryasz & McDermott, 2008).
The following post today gives a brief and detail description of the PFPS, and the therapeutic measures to cure the same.
Brief Background description of PFPS: Patello-femoral Pain Syndrome (PFPS) is a term for a variety of pathologies or anatomical abnormalities leading to a type of anterior knee pain (Waryasz & McDermott, 2008). There are many causes of PFPS and the following table lists some of them as described by Waryasz & McDermott (2008) in their article PFPS a system review and case-study.
Furthermore, it has also been noted that physical training including sport-specific cardiovascular training, plyometrics, sport cord drills, strength and flexibility training has been found in adolescent female soccer players to significantly reduce lower body injury incidence from 33.7% to 14.3%, allowing athletes to be game-ready ( Waryasz & McDermott (2008).
Specific Results showing the presence of PFPS.
a) Using electromyography (EMG) to measure neuro-motor dysfunction in PFPS has been analyzed in 5 studies. All 5 studies have determined that when comparing PFPS subjects to controls, there is significant neuro-motor dysfunction in PFPS. Thomee (1996) demonstrated that the vastus medialis muscle was less active on EMG in PFPS patients, while the rectus femoris was equally active to healthy controls while standing ( Waryasz & McDermott (2008). Cowan (2001) and Cowan (2002) determined that during activities of daily living there was a difference in EMG onset in PFPS compared to controls. Witvrouw (2000) found VMO/VL reflex response time to be a significant finding in PFPS. The VMO/VL reflex response time was determined by electromyography unit with skin electrodes over the VL and VMO muscle bellies. Readings were taken using the patellar tendon reflex with the test performed 10 times per . The VMO/VL muscles responded faster in the PFPS group compared to the controls. Although not statistically significant, the group noticed that the VMO fired earlier compared to the VL in the control, which would equate to an earlier activation of the medial force vector preventing lateral patella displacement. The authors concluded that an altered VMO/VL response time was a risk factor for PFPS.
b) Foot abnormalities: The ARCH index of the foot was significantly lower but not something as specific associated with PFPS.
c) Gastrocnemius Testing: Gastrocnemius and soleus tightness reduces the amount of dorsiflexion leading to excessive subtalar joint pronation and tibial internal rotation which will cause femoral internal rotation to increase the Q angle. PFPS is causes by increase in the Q angle and therefore, it was concluded in two major studies about the increase in the Q angle during Gastrocnemius Testing leading to PFPS. ( Waryasz & McDermott, 2008).
d) Ligament and Joint laxity: Generalized ligamentous laxity is proposed to increase the total patellar mobility which would alter patellar tracking and lead to symptoms ( Waryasz & McDermott, 2008). Generalized ligament laxity was noted in 2-3 patients during the major studies leading to PFPS.
e) Hamstring strength: Decrease in the Hamstring strength either causes pre-mature knee flexion or necessitate higher quadriceps forces to overcome the passive resistance of the hamstring, both of which may increase the plantar flexion joint reaction forces ( Waryasz & McDermott, 2008). Hamstring tightness was therefore evaluated and the studies showed increased in the Hamstring tightness in PFPS.
f) Hip Musculature Weakness: The iliopsoas muscle, a hip flexor and secondary femoral
external rotator, if weak de-stabilizes the. The individual then compensates by developing an anterior pelvic tilt with an internally rotated, the Q angle is then increased, leading to increased PF joint stresses ( Waryasz & McDermott, 2008).
There are still some other factors such as Illiotibial band tightness, Quadriceps’ Q angle increase, patella-mediolateral glide mobility and patellar tilting. All the above mention factors provide a thorough base to evaluate the symptoms of PFPS in a patient suffering from anterior knee pain.
THERAPEUTIC MODALITIES AND PHYSICAL THERAPY: The following are proposed by Lake & Wofford (2011).
Recommended modalities for use in patients with PFPS include
- cryotherapy for reducing pain and edema
- thermotherapy (therapeutic heat) for local vasodilation to reduce pain and stimulate healing, in the forms of ultrasound,moist hot packs,and warm whirlpool
- phonophoresisand iontophoresisto reduce inflammation and pain;
- monophasic pulsed stimulation for edema
- transcutaneous electrical nerve stimulation (TENS) for pain
neuromuscular electrical stimulation (NMES) to facilitate quadriceps muscle activity, which may be helpful in muscle reeducation in those who have acute pain, edema, or significant weakness and are unable to properly activate their vastus medialisand
- electromyography (EMG) biofeedback to promote selective activation of the vastus medialis for selective strengthening or to restore muscle balance in knee extension.
Physical Therapy can also include close-and open kinematic chain exercises, leg press, quadriceps sets of isometric exercises incorporating circuit and interval training modes.
I encountered a PFPS patient few weeks back and I noted that Continuous mode of Pre-
modulated Electrical stimulation along with close kinematic chain exercises does help a lot in the initial phases. The latter phase if includes circuit and interval training depending upon the specific patient produces quicker results. I also noted that biofeedback along with phonophoresis helps to produce quick results in young athletes and individuals.
Let me know your thoughts about PFPS by answering the following questions.
1) Have you ever suffered from PFPS? What was your experience with the recovery?
2) What kind of specific exercise helped you?
3) What activities triggered the occurrence of instability and pain in the knee?
4) Any continuous activity that you were not able to do?
5) Did you find it difficult going up and down the ramp or negotiating stairs?
6) How much time did it take to get you recovered?
All individuals and all the injuries are different. So it will be my pleasure to know your answers related to the questions mentioned above.
As always suggestions and questions are always welcomed. You can write me as email@example.com.
Thank you everyone and have a wonderful day ahead!!
Sweta Christian PT, DPT.
Waryasz, R.G., and McDermott, A.Y., (2008). Patello-femoral pain syndrome (PFPS): a systematic review of anatomy and potential risk factors. Dyn Med. 2008; 7: 9.
Published online 2008 June 26. doi: 10.1186/1476-5918-7-9.
Witvrouw E, Werner S, Mikkelsen C, Van Tiggelen D, Berghe L Vanden, Cerulli G. Clinical classification of patellofemoral pain syndrome: guidelines for non-operative treatment. Knee Surg Sports Traumatol Arthrosc. 2005; 13:122–130. doi: 10.1007/s00167-004-0577-6.
Cowan SM, Hodges PW, Bennell KL, Crossley KM. Altered vastii recruitment when people with patellofemoral pain syndrome complete a postural task. Archives of Physical Medicine & Rehabilitation. 2002; 83:989–995. doi: 10.1053/apmr.2002.33234. [PubMed].
Cowan SM, Bennell KL, Hodges PW, Crossley KM, McConnell J. Delayed onset of electromyographic activity of vastus medialis obliquus relative to vastus lateralis in subjects with patellofemoral pain syndrome. Archives of Physical Medicine & Rehabilitation. 2001;82:183–189. doi: 10.1053/apmr.2001.19022. [PubMed] .
Lake, D.A., Wofford, N.H., (2011). Effect of Therapeutic Modalities on Patients With Patellofemoral Pain Syndrome. Sports Health. 2011 March; 3(2): 182–189.doi: 10.1177/1941738111398583
- Affect of Early NMES in Quadriceps Muscle Strength after Total Knee Replacement (andreishmael.wordpress.com)
- The Many Benefits of a Foam Roller (wheatonchiro.wordpress.com)
- Neuromuscular Adjustments of the Quadriceps Muscle after Repeated Cycling Sprints (plosone.org)
- New Technology Could Be Used For Knee Replacement Therapy (pittsburgh.cbslocal.com)