Knee problems while cycling
Knee pain is an annoying and common injury among cyclists and shows up in various ways. Apart from traumatic injuries, problems related to the knee are always the result of overexertion. This means that the pain increases gradually over one or more rides and is only relieved when you are off the bike. If the irritation that causes the problem is great enough, the pain can also affect your daily life outside of cycling.
Knee pain can be roughly divided into two main categories:
1. Pain in the front or back of the knee. These complaints usually result from overstretching or bending the knee too deeply while cycling. Stiffness and fatigue of the hamstrings or quadriceps muscles are often the precursors of the complaint, which then worsen into severe pain as the strain of cycling continues during your ride. The painful structures are usually your patellar tendon (the large, triangular tendon that connects your kneecap to your lower leg) or the structures below it, and the hamstring attachment at the back of the knee. Less common are calf muscle attachments that form just above your knee at the back.
These problems usually start with a saddle position that is too high. Cycling experts have been using goniometers (joint angle meters) and motion recording software to measure knee angles for many years. You'll often hear that cycling experts and websites spread stories like “the knee angle at maximum stretch should be between 142 and 148 degrees and at minimum stretch... and so on.” These measurements are “rules of thumb” and are generally largely useless for most cyclists. For example, if you have particularly stiff hamstrings, glutes or a stiff lumbar spine, these “rules” will often result in physical complaints, including knee pain, if the bike is set up this way. This is one of the big reasons why I believe in personalized bikefit, where the person comes first. A good physical examination prior to the measurement is essential here.
Personally, I'm not in favor of clinging to a fixed knee angle that is used as a guide for saddle height and setback. The end result of such an adjustment often results in a saddle that is too high. Any increase in the saddle height above optimal will result in a certain degree of instability on the saddle (clearly visible with the help of a saddle pressure measurement). A saddle position that is too high will affect the entire chain of the leg. Knee pain, hamstring problems and pain in the gluteal region are often the result. I regularly see cyclists who have been adjusted using automated systems or motion recording software that are up to 40 mm too high. This software is good to use and to provide insight into an attitude, but not to blindly adopt. Every person is unique and therefore it is impossible to use the same posture/measurements for each person. The software should be seen as a tool and not a gold standard.
2. The other major category of knee pain is pain on the outside or inside of the knee. These are more difficult and have many possible causes. Simply put, the cause of knee pain is the result of knee movement that is out of sync with the direction of movement of the crank arm. The knee is a simple hinge joint that can only function properly if it moves in the right direction of movement. Any deviation of the knee in terms of rotational motion (rotation) or ovality in following the knee will result in excessive stress on the outer structures (the iliotibial band or “ITB” is a common culprit) or, less commonly, the inner structures of the knee. Often, the pain feels dull and “behind the kneecap” - this is a clear sign that the kneecap, the large bone at the front of your knee that works as a power couple for the quadriceps muscles, is being pulled forcefully out of its natural vertical movement pattern at the front of the thigh.
An incorrect kneecap pattern is the most common cause of the knee-related pains we see and can be caused by many different problems, almost all of which occur above or below the knee itself. The knee sits as a joint between the ankle and the hip. The position of these two joints therefore has a direct influence on the knee joint. Tight or weak muscles in the hip and upper thigh, an unstable arch, incorrect cleat placement, a seat that is too high or too low, or the wrong width of the pedals can all play a role in a faulty knee movement pattern. If we were to look even further into the entire setup of the bike, even the position of the steering wheel could also play a role in this.
We usually see cyclists with left knee pain. This is usually the result of a problem on the right side. It seems to be considerably more common for a rider to lower their right hip and roll forward than the left. Presumably due to the fact that most people are right-dominant. As a result, the control on this side has been better developed. If there are problems with the adjustment, we prefer to let one side (the dominant side) continue to function properly. As a result, the left knee is ultimately compromised.
Ultimately, the bike is a symmetrical object and we humans are not. The differences are very diverse and can be caused by both incorrect bike set-up and physical preferences.
As a result, there is ultimately no standard model that you can follow to achieve a personally optimal posture. Both an accurate physical examination combined with the correct interpretation of the software that we have at our disposal as bikefitters are important to achieve your ideal posture. This picture can change as our training and mobility will also change over time. Finally, we should certainly not lose sight of someone's personal goal, which also determines the final position.
