Runner's knee: patellofemoral pain and iliotibial band syndrome
"Runner's knee" is the most frequent reason runners come to the clinic. Behind that popular label sit two distinguishable conditions, patellofemoral pain and iliotibial band syndrome, which call for different management yet share something important: the response to treatment depends more on active work than on rest.
Two conditions, one group
Patellofemoral pain (PFP) is felt at the front of the knee or around the kneecap and typically appears when climbing or descending stairs, squatting or running. Iliotibial band syndrome (ITBS) is felt on the outer side of the knee, over the lateral femoral condyle, mostly on longer runs. They share two clinically useful features: targeted exercise is the foundation of treatment, and the most consistent risk factor for getting injured again is having been injured before.
The scale of the problem
The knee is the most injured site in long-distance runners
Systematic review of injuries in long-distance runners: annual incidence from 19.4% to 79.3% depending on the population studied. The knee is the most frequent site. The most consistent risk factor for getting injured again is a history of previous injury.
That wide spread of figures (19-79%) reflects the heterogeneity of definitions and populations, but the pattern is stable: the knee carries the bulk of the injury burden in runners. Managing training volume and completing recovery after the first injury are the critical points for preventing recurrence.
van Gent RN, Siem D, van Middelkoop M, van Os AG, Bierma-Zeinstra SM, Koes BW. Incidence and determinants of lower extremity running injuries in long distance runners: a systematic review. Br J Sports Med. 2007;41(8):469-80. doi:10.1136/bjsm.2006.033548
Patellofemoral pain is very common
Annual prevalence of 22.7% in the general population
Systematic review and meta-analysis of 23 studies: annual PFP prevalence of 22.7% in the general population and 28.9% in adolescents; incidence in amateur runners of 1,080.5 cases per 1,000 person-years; point prevalence of 22.7% in adolescent female athletes (95% CI 17.4-28.0%).
The long-term prognosis of PFP is worse than was assumed for years, and recurrences are common when the first episode is not managed well. The large number matters: any runner presenting with anterior knee pain deserves a careful assessment, not a quick discharge.
Smith BE, Selfe J, Thacker D, Hendrick P, Bateman M, Moffatt F, et al. Incidence and prevalence of patellofemoral pain: A systematic review and meta-analysis. PLoS One. 2018;13(1):e0190892. doi:10.1371/journal.pone.0190892
Risk factors: what counts, what does not
Age, weight, BMI and the "Q angle" do not predict PFP
Systematic review and meta-analysis of 18 prospective studies with 4,818 participants (483 developed PFP during follow-up): age, height, weight, BMI, body fat percentage and Q angle are not predictive risk factors. In military recruits, quadriceps weakness does predict PFP (SMD −0.69; 95% CI −1.02 to −0.35). In adolescents, paradoxically, greater hip abduction strength was a risk factor (SMD 0.71; 95% CI 0.39 to 1.04).
The clinical conclusion: PFP is not prevented by losing weight or "measuring the Q angle", but by attending to muscle patterns, gait mechanics and the progression of training load. The paradoxical finding in adolescents tempers the simplistic message of "strengthen the gluteus medius and job done".
Neal BS, Lack SD, Lankhorst NE, Raye A, Morrissey D, van Middelkoop M. Risk factors for patellofemoral pain: a systematic review and meta-analysis. Br J Sports Med. 2019;53(5):270-281. doi:10.1136/bjsports-2017-098890
Treatment: 2018 international consensus
Combined hip and knee exercise and custom orthoses, recommended
Consensus statement from the 5th International Patellofemoral Pain Research Retreat, voted by 41 experts. Recommendations in favour: therapeutic exercise, especially the hip plus knee combination, combined interventions, and custom orthoses to improve pain and/or function. Against: patellar, knee or lumbar mobilisations used in isolation; electrophysical agents as the main treatment.
Left in a grey zone (no recommendation for or against, for lack of evidence): patellar taping or bracing used alone, acupuncture and dry needling, manual soft-tissue techniques, blood flow restriction training and running retraining. For iliotibial band syndrome, management follows similar lines (progressive exercise plus biomechanical correction plus a review of training volume), although the comparative evidence base is more limited than in PFP.
Collins NJ, Barton CJ, van Middelkoop M, Callaghan MJ, Rathleff MS, Vicenzino BT, et al. 2018 Consensus statement on exercise therapy and physical interventions (orthoses, taping and manual therapy) to treat patellofemoral pain. Br J Sports Med. 2018;52(18):1170-1178. doi:10.1136/bjsports-2018-099397
Why add hip work, not just quadriceps work
Adding hip exercise to quadriceps work reduces pain further, at one year too
Systematic review and meta-analysis of 14 studies (seven of high quality): there is strong evidence that combining hip muscle work with quadriceps work reduces pain and improves function in the short term, with moderate evidence in the medium term. Most relevant for runners: the combination achieves greater pain relief and better function at one year than training the quadriceps alone.
The hip governs much of what happens to the knee on every foot strike: when the muscles that stabilise the pelvis and control the thigh do not respond, the kneecap ends up paying for it. That is why a programme that builds strength and control at the hip and knee together performs better than the classic quadriceps-only approach. The review offers no single summary figure because it pools different protocols, but the direction of the effect is consistent and holds over time.
Lack S, Barton C, Sohan O, Crossley K, Morrissey D. Proximal muscle rehabilitation is effective for patellofemoral pain: a systematic review with meta-analysis. Br J Sports Med. 2015;49(21):1365-1376. doi:10.1136/bjsports-2015-094723
Orthoses: when they genuinely help
A well-indicated orthosis brings relief quickly and performs like a full programme
Randomised clinical trial with 179 people aged 18 to 40 with patellofemoral pain. Orthoses improved pain compared with a flat, shapeless insert as early as six weeks (number needed to treat of 4) and an orthosis performed as well as a full physiotherapy programme. At 52 weeks, all groups had clearly improved.
The useful message for runners is twofold. First, an orthosis acts quickly and with very little risk when there is a mechanical factor to offload. Second, that a well-chosen orthosis matches a full physiotherapy programme speaks to its value in the right case. The trial used off-the-shelf prefabricated orthoses; the step up in quality comes from analysing each person's gait and deciding which orthosis and for whom, which is exactly where a biomechanical assessment and custom orthoses make the difference.
Collins N, Crossley K, Beller E, Darnell R, McPoil T, Vicenzino B. Foot orthoses and physiotherapy in the treatment of patellofemoral pain syndrome: randomised clinical trial. BMJ. 2008;337:a1735. doi:10.1136/bmj.a1735
Take-home
- Knee pain in runners covers two main conditions (PFP and ITBS) with partially shared treatment.
- Prospective evidence rules out the Q angle, BMI and weight as predictive risk factors.
- Combined hip and knee exercise and custom orthoses carry an international consensus recommendation in their favour; isolated passive techniques do not.
- Adding hip work to quadriceps work gives better results, at one year as well, than training the quadriceps alone.
- Orthoses bring relief quickly and, when well indicated, perform like a full physiotherapy programme; the key is analysing the gait to choose which one and for whom.
- A progressive return to running, not a straight return, is what prevents recurrence.
At Avanza Salud we can help
We manage runner's knee with a comprehensive approach: a biomechanical gait assessment to detect the factors overloading the knee, Podonexus custom orthoses when indicated, musculoskeletal ultrasound to rule out associated tendon or cartilage problems, and a physiotherapy and return-to-sport programme with progressive hip and knee exercise, a gradual return to running and reassessment. If you have had anterior or lateral knee pain when running for several weeks, it is worth treating it properly before it becomes persistent.