One of the most common causes of knee pain in running is Patellofemoral Pain (PFP), or “Runners Knee”. PFP is defined as pain localised behind the knee cap. This pain usually has a gradual onset rather than a direct trauma.
What causes patellofemoral pain?
Consistently overloading any joint will increase risk of pain and injury. In relation to the patellofemoral (PF) joint, running can lead to PF joint loads 4.5-7.6 times body weight per step! If a runner suddenly increases how far or how often they are running, these loads can add up quickly and lead to increased knee pain (1).
Signs and symptoms
- Anterior knee pain localised to behind the knee cap.
- Knee pain that worsens as you run.
- Anterior knee pain on stair climbing, squatting or sitting for extended periods of time.
1. Do not stop running
We never tell runners to stop running when they come to us with PFP. This is because we know they won’t…. and it’s not necessary. However, most runners with PFP are overloading the PF joint. So we do recommend some initial changes to your training load.
- Reduce the length of your runs. Longer runs are likely to exacerbate your anterior knee pain. Research recommends running short distances more often, rather than fewer longer runs. This avoids overloading the PF joint but provides enough stimulus to promote healing tissue adaptations (2)
2. Use pain as your guide
- During the initial stages of treatment, pain is your best guide when running. Research suggests keeping your pain below 2-3/10 when running. This pain should then reduce back to resting levels within 24 hours post run. If pain exceeds these limits, you are overloading the PF joint. Keeping your knee pain within these levels will avoid exacerbating the injury (3).
- Initially avoiding hills and stairs when running will help keep your pain levels within the acceptable range.
3. Strengthen your legs!
- We all know most runners tend to avoid the gym. However, increasing strength in hip and knee muscles is essential to improving your bodies ability to manage load when running (2). Research has found that quadriceps resistance training is particularly useful for improving symptoms of runners knee (2).
- Research suggest doing weighted lower limb exercises such as Squats, Calf Raises, Seated Calf Raises, Single Leg Press, Clams, Step ups and Seated Knee Extension.
- For more detail on Strength Training, read our article on Strength Training and Running.
4. Alter your running gait (not for everyone)
- Increasing your cadence (steps per minute) by 5% – 7.5% can help reduce loads on the PF joint by naturally shortening your step length (1). Metronome apps can assist in finding your current cadence and to help increase it. Most smart watches can also monitor your cadence. Only try this if you have a low cadence to begin with. A cadence of 170-190 is standard. For example, this strategy would be appropriate for someone with a cadence of 150 who lands with there foot well out in front of them.
- Some runners look like they are running on a tight rope. This narrow running pattern can increase abnormal loads on the PF joint. To widen your step width, think about “pushing your knees out to the side” when running. This cue along with hip exercises can help widen your running pattern and improve symptoms.
5. Do not rely on passive treatments such as massage and dry needling
- Research shows passive treatments such as massage, electrotherapy, dry needling and acupuncture do not have any long term benefit when used alone (2). These are forms of short term pain relief (like paracetamol and ice packs) and are only of use when in conjunction with the first 4 treatment strategies. Don’t believe anyone that tells you a sports massage will help patellofemoral pain in the long term.
References
1. Barton CJ, Bonanno DR, Carr J, et al. Running retraining to treat
lower limb injuries: A mixed-methods study of current evidence
synthesised with expert opinion. Br J Sports Med 2016;50: 513-26.
2. Collins NJ, Barton CJ, van Middelkoop M, et al. 2018 consensus
statement on exercise therapy and physical interventions
(orthoses, taping and manual therapy) to treat patellofemoral
pain: Recommendations from the 5th international patellofemoral
pain research retreat, gold coast, australia, 2017. Br J Sports Med
2018;Epub ahead of print 2018 Jun 20.
3. Esculier, J. F., Bouyer, L. J., Dubois, B., Fremont, P., Moore, L., McFadyen, B., & Roy, J. S. (2017). Is combining gait retraining or an exercise programme with education better than education alone in treating runners with patellofemoral pain? A randomised clinical trial. Br J Sports Med, bjsports-2016.