The most common knee injuries in runners are, unsurprisingly, often caused by overuse. This is because repeated movements can wear out or damage the tendons and soft tissues in and around your knees.
The biggest risk factor for sustaining a running knee injury is overuse. However, other risk factors include any inherent imbalances in the muscles around your knees, as well as performing exercises that may excessively contract and extend these muscles.
Other risk factors include prior injuries to the knee that cause long-term damage or weakness, or imbalances in your muscles.
Injury, ageing, overuse and any inherent alignment problems in your knee joint can all cause chondromalacia patellae. This condition refers to softening and breakdown of the cartilage in your knee, resulting in knee pain and an increased risk of other knee injuries.
Patellofemoral pain refers to pain at the front of your knee and is the most common knee complaint in runners. Often the cause is biomechanical eg your kneecap (patella) sits too high, there is excessive friction between your kneecap and underlying bones on movement or there is a muscle imbalance.
Patellofemoral pain is treated with rest, taking over-the-counter painkillers and performing daily physiotherapy to rehabilitate your knee, which includes stretching and strengthening exercises to increase the flexibility of your knee.
The iliotibial band is a thick band of tissue that runs from the outer side of your knee all along the outer side of your thigh. Repeated bending and straightening can cause the iliotibial band to rub against the lower part of your thigh bone (femur), which forms part of your knee joint. This causes pain on the outer side of your knee.
ITB syndrome is treated with rest, taking over-the-counter painkillers and anti-inflammatory drugs, and performing knee strengthening and stretching exercises to improve the flexibility of your knee and the strength of the muscles that support and move it.
Bursae are jelly-like sacs found in your joints that act as cushions to make movement easier. Each of your knees contains up to 11 bursae, with five main bursae. Bursitis occurs when these sacs become inflamed, causing pain, tenderness and warmth. Although knee bursitis is often caused by excessive kneeling, it can also occur due to overuse from running.
Treatment for bursitis includes rest, elevating your leg whenever possible, applying ice packs and taking over-the-counter painkillers and anti-inflammatory drugs. Surgery is not usually needed, however, in persistent cases, your doctor may recommend a steroid injection into the affected part of your knee.
Tendonitis refers to inflammation of one or more of your tendons due to overuse. In runners, tendonitis that causes knee pain is usually caused by inflammation of or microtears in the patellar tendon or quadriceps tendon. Your risk of tendonitis is increased if your hamstrings and quadriceps are tight, which results in greater stress at the point where the muscles attach to bones in your knee. It is, therefore, important to perform stretches before and after running.
Treatment for tendonitis includes rest, bandaging for support, elevating your leg whenever possible, performing daily stretching exercises, applying ice packs and taking over-the-counter painkillers and anti-inflammatory drugs. In persistent cases, your doctor may recommend a steroid injection and in cases where the tendon is damaged, surgery may also be needed.
If you have been running for many years, the cartilage in your knees may become worn out and thin. This increases the friction in your knee joint on movement and over time, may cause knee pain. Knee strengthening exercises can help reduce the strain on your knees, however, in the long-term, you may need to switch to lower impact exercises.
Consider treadmill vs. road running
There are pros and cons to both running on a treadmill and running on the road. A treadmill provides more controlled movement and produces less of a ground reaction force, which makes it kinder on your knees and ankles. If you are running again after a significant break from running or after recovering from an injury, it is best to start on a treadmill so you can ease your body back into it.
Running outside on the road can be more fun and you may, therefore, feel more inspired to run further and increase your endurance. Spending time outside in fresh air and sunshine also has its own health benefits.
Wear supportive shoes
Wearing supportive, well-fitting shoes will reduce your chances of sustaining a knee injury. If your running shoes are worn down or have lost their shape, then it’s time to get a new pair.
Currently, there is no evidence to suggest that cushioned insoles reduce your risk of a knee injury.
Always warm up
Before you do any form of exercise, including running, it is important to warm up and stretch out your muscles to avoid injury.
Build up your running gradually
If you want to increase the duration or intensity of your running it is important to do so gradually to avoid injury.
Use foot orthotics where appropriate
Some people have pronated feet, which means that their feet turn inwards when landing on the ground while walking or running. Foot orthotics are specially designed inserts that aim to correct the pronation by supporting the inner side of your foot. This can, in theory, improve your running and consequently reduce your risk of injury.
Lose excess weight
Excess weight puts greater strain on your load-bearing joints, which includes your knees. Losing any excess weight, by following a healthy, balanced diet and exercising regularly, will therefore reduce your chances of a knee injury.
Strengthen your thighs
Your thigh muscles support your knees and the stronger they are, the less strain is placed on your knee joints. It is, therefore, important to perform regular stretching and strengthening exercises that focus on your thigh muscles.
Know when to stop
If, while running, you start to feel pain in or around your knee, stop and rest your knee. You may have sustained an injury through overuse, so give your knee a chance to recover and heal.
Similarly, if you have been running for years, you may notice that as you get older, running at the same intensity as you used to causes you knee pain. It is important to recognise when it’s time to switch to lower impact exercises. If running on the road is straining your knees, you can try using a crosstrainer or static bike, or taking up swimming.
Mr Ahmad Mobeen Ismail is a Consultant Orthopaedic Surgeon at Spire Manchester Hospital, specialising in sports injuries, knee injuries, knee arthroscopy, hip and knee arthritis, and hip and knee replacement. He has further advanced his expertise by visiting centres of excellence in orthopaedic surgery in the US and Europe to learn new techniques. His current interests lie in promoting short-stay hip and knee replacements via minimally-invasive surgery and new techniques for pain control and rehabilitation.