Mountain biking with osteoarthritis: What's good for your knees & what's not?

Chronic wear and tear of the joint cartilage is known as osteoarthritis. Knee joints are particularly frequently affected. Osteoarthritis is the most widespread knee problem worldwide. In Germany, osteoarthritis is the most common reason for treatment in orthopaedic prevention and rehabilitation centres. In Switzerland, knee injuries are the second most common health problem of all after hay fever. The risk of osteoarthritis increases significantly from the age of 50. But those affected are getting younger and younger. High loads and injuries to the knee joint increase the risk of developing osteoarthritis. This seems to be particularly bad news for mountain bikers, as two thirds of injuries sustained while biking affect the lower extremities. Is mountain biking even recommended for those at risk of osteoarthritis or even acute osteoarthritis?

Osteoarthritis affects most people sooner or later. As a result of a knee injury, I already have a high risk of osteoarthritis at the age of 30. Nevertheless, I want to continue mountain biking in another 30 years. Fortunately, there are preventative measures I can take to enjoy my natural knee for as long as possible. The longer the insertion of an implant can be delayed with a clear conscience, the further medicine will hopefully progress. - Jan Timmermann, BIKE editor

What causes osteoarthritis of the knee?

To understand what happens in the knee joint and how osteoarthritis can occur, it is helpful to take a look at the most important elements of the knee. Many cyclists only realise how complex its structure is after an injury.

The joint: The fibula, tibia and femur come together in the knee. The latter has a cylindrical head that can rotate in a socket at the end of the tibia. This hinge and pivot joint allows the knee to move through 180 degrees. The last ten degrees of extension are only possible with simultaneous external rotation of five degrees.

The Mensiken: Due to a different curvature, the bones in the knee do not fit together as well as in other joints. This is why the knee joint is supported in two cartilage rings. These menses act as a kind of shock absorber to distribute the load more evenly. One-sided strain and injuries favour their wear and tear.

The tapes: Healthy cruciate ligaments are always taut and thus prevent the thigh from sliding off the tibia. In full extension, the two collateral ligaments are also taut to counteract hyperextension and over-rotation of the lower leg.

The muscles: A large number of different muscles work together and against each other to flex and extend the knee and provide stable support for the joint. The strongest muscle in the human body is the four-headed thigh muscle, which extends over the front and part of the inside. The adductor muscles are located on the inside of the thigh and the ischiocrual muscles on the back. The most prominent muscles in the lower leg are the long and short fibular muscles.

The cartilage: The joint is made up of supporting connective tissue that does not have its own metabolism. The cartilage is supplied with nutrients by loading and unloading the surrounding tissue, for example when pedalling. Over time, the cartilage loses substance and the underlying bone can be damaged. Undersupply and injuries accelerate cartilage degradation. If the signs of wear become chronic, doctors diagnose osteoarthritis. The most common consequences include pain and restricted movement.

I used to ride BMX a lot. Quite apart from the risk of injury, hard impacts on a bike with zero damping are no longer an option after my knee injury. I also no longer dare to attempt single-speed rides of several hundred kilometres in length, despite the ergonomic material. It's important for me to understand exactly what's going on in my knee. With regular medical and therapeutic advice, a good body awareness and targeted training, my limitations when mountain biking remain manageable and the risk of osteoarthritis can be controlled. - Jan Timmermann, BIKE editor

Biking with osteoarthritis risk? Three questions for the expert

Lorenz Westner has been coaching numerous top athletes at the FFB Puch sports school for many years - including mountain bikers. He has been working with Danny MacAskill for twenty years, Emil Johansson trained with him for months, he developed a training system with Fabio Wibmer and Tarek Rasouli, Erik Fedko, Steffi Marth, Loris Vergier and many more are also among "Lenz's" athletes. We asked the expert three burning questions about mountain biking with osteoarthritis.

BIKE: Can mountain biking also be recommended for osteoarthritis patients?

LORENZ WESTNER: Absolutely! In rehab, we try to get people on a bike as quickly as possible. Cycling is a very good endurance sport for injuries of this type. Due to the pre-damaged structure in osteoarthritis patients, the metabolism of the tissue has a harder time and inflammatory processes take place in the body. Osteoarthritis only hurts when it is activated, i.e. inflammatory. This can happen, for example, when the body is overloaded, but also after viral infections or when the immune system is weakened.

What should mountain bikers with osteoarthritis avoid?

Knee patients are often told what they shouldn't do. Athletes should be able to do what they love again as much as possible, because that determines their quality of life. People have very different perceptions of pain. However, it is important to give the body time to recover from such an injury. Doing high-intensity intervals twice a week is not necessarily recommended due to the high forces in the knee. It may not have to be an 18 per cent incline. If you are content with five or six per cent, you can still regulate the pressure nicely. It is always important to try to minimise the strain on the joint. You will probably be under strain during a tour anyway. However, nothing needs to be forced during training - it is better to emphasise good technical sequences and a high cadence.

If I'm at risk of osteoarthritis, can I still clatter through the roots on a hardtail?

Vibrations that act directly on the joint are of course problematic. With the fine vibrations on a freshly prepared ski slope with small grooves, for example, osteoarthritis patients often begin to realise that something is wrong with their knee. Muscles are the shock absorbers in the musculoskeletal system. Much more is possible with optimally trained muscles. The more efficient they are, the better they can process shocks. It becomes problematic when the body is unable to adjust the muscle tension correctly because the muscles are too stiff or out of balance. I would recommend anyone affected by osteoarthritis and travelling off-road to get a fully on which they can sit comfortably. Well-adjusted suspension elements eliminate most of the additional stress caused by vibrations.

Together with Lorenz Westner, we have also put together the best exercises for knee problems in a video - have fun watching and doing them!