
Knee pain and injuries are a common ailment among runners. Their causes are multiple, to be sought both from a biomechanical defect and from training conditions. Generally speaking, the knee joint is one of the most stressed by running, which requires an appropriate prevention strategy regardless of the type of running practiced. What causes knee pain when running? How to effectively prevent and treat this pain?
What is windshield wiper syndrome?
In common parlance, we speak of “windshield wiper syndrome” to refer to iliotibial band syndrome , a knee pain rightly considered to be the runner's bane.
Located on the outer side of the knee, this condition corresponds to pain in the iliotibial band, a tendon tissue located on the outer side of the thigh. Highly used when running, this tendon strip extends from the top of the thigh to the outer side of the knee.
According to a recent systematic review, windshield wiper syndrome is:
The fifth most common injury related to running , all areas of the body combined
The second most common knee injury among runners, after patellofemoral syndrome
A study published in 2024 and covering 255 trail runners in Reunion shows that 54.9% of them have already suffered from this injury, confirming the importance of prevention and treatment of windshield wiper syndrome in the running practice. According to the review mentioned above, patellofemoral syndrome (also called patellar syndrome) is by far the most common first injury in runners, all areas combined; in fact, it represents approximately 17% of the total of all injuries . Hence the importance of a global prevention strategy, whatever the level of the runner, in order to avoid knee injuries.
What causes knee pain when running?
The high prevalence of knee injuries during running is explained by the high demand on this joint when we run; thus, the slightest “risky” parameter, such as a change in training conditions or an intrinsic weakness of the runner, can trigger more or less severe pain.
When knee pain is not caused by trauma, its appearance can be explained by different factors. We distinguish between intrinsic factors, which are physical causes linked to the anatomy of each runner, and extrinsic factors, which correspond to the conditions of the race.
Among the intrinsic factors that promote knee pain, we mainly find:
Excessive internal rotation of the knee
A genu varum (outward deviation of the knee)
A lack of alignment of the ball joint
Excessive hip adduction
A bony prominence causing friction of the iliotibial band
Excessive pronation of the foot (foot turned inward)
According to the study already mentioned on trail running in Reunion, young age and being a woman favor the occurrence of windshield wiper syndrome. Finally, we must not neglect excess weight, which can place excessive strain on the knees and promote disorders.
In terms of extrinsic factors , the runner whose knee is painful can look at:
His training load (perhaps excessive, or increased too suddenly)
The surface on which he runs (asphalt, athletics track, uneven terrain)
A sudden change in altitude in his training
A recent change of shoes, for example having different cushioning
An increase in downhill running, which puts more pressure on the knees
Furthermore, insufficient or inappropriate practice of muscle strengthening of the lower limb can also promote knee injuries.
Most of these factors are modifiable, which allows you to return to running in optimal conditions and without pain. As for physical factors, it is not always possible to correct them, however the runner can adapt his technique to minimize the risk of injury.
How to prevent and treat knee pain related to running?
Primary prevention of knee pain while running is based on knowledge of the risk factors, allowing their management and correction. For example, we know that iliotibial band syndrome is more common in people with genu varum, in women, in young and/or inexperienced runners, and in those with insufficient muscle strengthening. Thus, each of these points can be worked on by the runner himself, ideally under the supervision of a health professional such as a physiotherapist, as part of active rehabilitation .
Physiotherapy plays a key role in both the prevention and treatment of knee injuries. Indeed, thanks to muscle strengthening exercises (internal rotators, quadriceps) supplemented by an improvement in his motor pattern (hip rotation, foot drop), the runner learns to better distribute the loads supported by the knee during the effort, which reduces the risk of injury. Several studies have also shown the role of strengthening the trunk (sheathing) in the treatment of patellofemoral pain syndrome; very satisfactory, the results were measured in terms of reduction in pain, stability and joint function, and finally muscle strengthening.
In the event that the architecture of the foot is involved in the pain syndrome, a consultation with a podiatrist may be indicated, resulting in the making of suitable orthopedic insoles .
Finally, it is up to each runner to monitor their training conditions to adapt them if necessary: for example, if the onset of pain coincides with wearing new running shoes, it is better to change them or return to the old pair. Likewise, it may be a good idea to change your route if a significant difference in altitude or a significant number of descents seems to match your pain.