25% Of Us Have Knee Pain Due To…

Our knees hate us. Or at least it can seem that way when they aren’t doing what we want them to do. Creaky, achy, and wonky knees are all too common among my friends when I ask them to help me move. And while those may be excuses for them, I bet it’s a reality for most of you. The sad part is that because the knee is so complex, it is often misunderstood. When you have a bum knee, rest is almost never the answer. This is particularly true for the 25% of us who will end up having knee pain due to patellofemoral pain syndrome (PFPS) (1). Also known sometimes as runner’s knee, PFPS is a complex issue without one true solution. Let’s take a look at why the knee cap can make us feel like knee crap!

As the name implies, PFPS is not a single problem but a group of signs and symptoms. Generally, the epicenter of the pain is somewhere under or around the kneecap, and will usually be mainly on the front of the knee. It can be caused by variations in strength, flexibility, patellar tracking, quadriceps angle, and patellofemoral joint (PFJ) morphology and even psychological issues such as depression, fear-avoidance, and anxiety (2). However, I like to think of PFPS as the knee leaving homeostasis. Homeostasis can be described as a zone, or “envelope of function”, where the tissue is capable of tolerating loads (3). So as you get stronger, you increase your envelope of function. And when you over-do it with your training, your knee may no longer tolerate levels of loading even during routine activities, such as descending stairs or previously well-tolerated running distances (4). In other words, when you over-do-it with your training or exercise, you may not be able to do half as much as you used to without pain.

While I would love to tell you how to screen yourself for potential red flags, there really aren’t any good predictors of injury (5). What will help you out is strengthening the quadriceps (6). By using a progressive overload scheme (aka gradually doing more over time), you can make those quads stronger and avoid pain and/or injury! Here are some exercises to try out for good quad activation and strengthening (4):

 – Knee extension with a weight attached to the ankle

 – A knee extension machine

 – Single leg squat to at least 65 degrees of knee flexion

 – Squatting between 0 and 45 degrees of knee flexion

 – Leg presses between 0 and 45 degrees of knee flexion

You can also try taping (anywhere on the front of the knee) or bracing the knee to alleviate the pain. You can pretty much tape your knee however you want because it doesn’t change the biomechanics of the knee (7). Strengthening the hip muscles will be helpful for more than just bikini season because strengthening those glutes (and other muscles of the hip) can help reduce pain and improve function (8). Similar to taping and bracing, strengthening the hips won’t improve biomechanics. Hip strengthening will, however, increase the load tolerance of the knee and supportive structures (9).

This segment is for runners, so feel free to skip it if you don’t anticipate doing a 5k anytime soon. Runners, in particular, are susceptible to having issues with their movement patterns that can lead to knee issues. Movement re-education through simple techniques can be extremely helpful for reducing knee pain. Reducing hip drop while running is a great way to help reduce knee pain. In addition to using glute strengthening techniques, mirror and verbal feedback can reduce hip drop and hip adduction (knee movement inwards) while running (10). A general increase in step rate by 5-10% can also be very beneficial for reducing knee load and pain (11). A metronome works great for achieving a faster gait pattern.

While knee pain may never be completely eliminated, there are some steps that can be taken to decrease pain and the likelihood of developing pain. Work toward having strong quadriceps, move with good technique and don’t advance your exercise routine too quickly. And while shock absorbing insoles and arch supports may be useless, throwing on a little tape or knee support may give you enough pain relief to build up your leg strength (12). For runners, watch yourself in the mirror and make sure you don’t have hip-drop and increase your running cadence. Just because PFPS is common doesn’t mean you have to develop it or that it will last forever. So don’t stop moving!

References

1. Nunes, G. S., Stapait, E. L., Kirsten, M. H., de Noronha, M., & Santos, G. M. (2013). Clinical test for diagnosis of patellofemoral pain syndrome: Systematic review with meta-analysis. Physical Therapy in Sport : Official Journal of the Association of Chartered Physiotherapists in Sports Medicine, 14(1), 54-59. doi:10.1016/j.ptsp.2012.11.003
2. Meira, E. P., & Brumitt, J. (2011). Influence of the hip on patients with patellofemoral pain syndrome: A systematic review. Sports Health: A Multidisciplinary Approach, 3(5), 455-465. doi:10.1177/1941738111415006
3. Gabbett, T. J. (2016). The training-injury prevention paradox: Should athletes be training smarter and harder? British Journal of Sports Medicine, 50(5), 273. doi:10.1136/bjsports-2015-095788
4. Willy, R. W., & Meira, E. P. (2016). CURRENT CONCEPTS IN BIOMECHANICAL INTERVENTIONS FOR PATELLOFEMORAL PAIN. International Journal of Sports Physical Therapy, 11(6), 877.
5. Whittaker, J. L., Booysen, N., de la Motte, S., Dennett, L., Lewis, C. L., Wilson, D., . . . Stokes, M. (2016). Predicting sport and occupational lower extremity injury risk through movement quality screening: A systematic review. British Journal of Sports Medicine, , bjsports-2016-096760. doi:10.1136/bjsports-2016-096760
6. Kooiker L Van De Port IG Weir A Moen MH. Effects of physical therapist-guided quadriceps-strengthening exercises for the treatment of patellofemoral pain syndrome: A systematic review. J Orthop Sports Phys Ther. 2014;44(6):391-B391.
7. Whittingham M Palmer S Macmillan F. Effects of taping on pain and function in patellofemoral pain syndrome: A randomized controlled trial. J Orthop Sports Phys Ther. 2004;34(9):504-510.
8. Lack, S., Barton, C., Sohan, O., Crossley, K., & Morrissey, D. (2015). Proximal muscle rehabilitation is effective for patellofemoral pain: A systematic review with meta-analysis. British Journal of Sports Medicine, 49(21), 1365-1376. doi:10.1136/bjsports-2015-094723
9. Willy RW Davis IS. The effect of a hip-strengthening program on mechanics during running and during a single-leg squat. J Orthop Sports Phys Ther. 2011;41(9):625-632.
10. Willy, R. W., Scholz, J. P., & Davis, I. S. (2012). Mirror gait retraining for the treatment of patellofemoral pain in female runners. Clinical Biomechanics (Bristol, Avon), 27(10), 1045-1051. doi:10.1016/j.clinbiomech.2012.07.011
11. LENHART, R. L., THELEN, D. G., WILLE, C. M., CHUMANOV, E. S., & HEIDERSCHEIT, B. C. (2014;2013;). Increasing running step rate reduces patellofemoral joint forces. Medicine & Science in Sports & Exercise, 46(3), 557-564. doi:10.1249/MSS.0b013e3182a78c3a
12. Bonanno, D. R., Landorf, K. B., Munteanu, S. E., Murley, G. S., & Menz, H. B. (2016). Effectiveness of foot orthoses and shock-absorbing insoles for the prevention of injury: A systematic review and meta-analysis. British Journal of Sports Medicine, , bjsports-2016-096671. doi:10.1136/bjsports-2016-096671