Why Do My Knees Click and Crack?

The joints in our bodies are where two or more bones meet; they are surrounded by connective tissue and allow us to move. Sometimes our joints make a noise, and they may make creaking, clicking, popping or cracking noises. It is a common misconception that cracking or clicking knees is a phenomenon confined to the elderly, it can however, be observed across a wide cross section of ages, from young adults to the elderly.

Although some people may find the sound of clicking knees worrying or disturbing, it is not usually an indication of any type of serious problem unless it is accompanied by pain or inflammation. If this is the case, it should be investigated by a physiotherapist or other health professional as it may be the result of an underlying issue.

The medical term for a creaking or cracking joint is ‘crepitus’. It is important to distinguish between crepitus of the joints and crepitus of the lungs; a crackling noise in the lungs is typically an indication of a respiratory infection or other type of problem. Crepitus of the knees is a cracking sound that is more often than not related to a particular activity, such as walking, going up or down the stairs, squatting or running for example.

why do my knees click

What Causes Cracking & Clicking Knees?

Historically, clinicians believed that a clicking or cracking sound was caused by an accumulation of small air bubbles within the synovial fluid of the joint. Synovial fluid is found in all of our joints and helps to lubricate and protect them. Until relatively recently, the general consensus was that during movement, pressure changes within the joint caused these tiny air bubbles to burst, and it was this that made the cracking noise. However, more recent studies suggest that the sound is due to the formation of pockets of air rather than the collapse of them.

Damaged Cartilage

Another reason for clicking knees may be irritated cartilage. This is sometimes caused by a loss of cartilage (chondromalacia), where the cartilage covering our knees begins to break down with age, becoming worn or even breaking off. In some cases, this results in fraying at the edges of the cartilage. During movement of the knee joint, these uneven edges rub against one another and create a popping or clicking sound. Loose or damaged cartilage does not always interfere with normal motion, if it does then treatment may be required to remove the damaged edges. Worn cartilage can be an indication of the onset of arthritis.


Arthritis is the general term that refers to the degeneration and inflammation of a joint. With age-related wear and tear, the joint begins to degrade and become subject to inflammation. Osteoarthritis is a chronic degenerative disease that causes damage to your joints. It is the most common form of arthritis and occurs when the cartilage within the joint breaks down and the underlying bone structure itself begins to change. This causes the joints to become stiff, inflamed and often very painful which negatively impacts mobility and can make day-to-day activities difficult. Some people with osteoarthritis report grinding, popping or clicking noises of the knee joint.

Meniscus Tears

The meniscus is a rubbery shaped disc that cushions the knee and helps to absorb shocks during motion as well as distributing weight evenly so that the bones do not rub together. As we age, tears and damage to the meniscus become more common. In younger people, it is usually a result of trauma such as a sudden twisting movement or a sudden impact during sport.

Alterations To The Ligaments Or Tendons

Ligaments and tendons connect bone to bone, or bone and muscle together, allowing us to move and bend. Sometimes the ligaments of the knee can become tight. This can be caused by a lack of movement or repetitive strain during exercise. Sometimes a ligament or tendon can pop out of place during movement causing an audible sound, as well as causing pain and inflammation. Issues with the ligaments or tendons can usually be resolved with physiotherapy, pain relief medication and rest.

How To Maintain Healthy Knees

Maintaining a healthy body weight through a good diet, regular exercise and movement, plays a key role in keeping our joints healthy. Ensuring that the muscles around the knee are strong, will help to support the joint; walking, squats, lunges, cycling and swimming are all good types of muscle building exercises. Remembering to warmup, cool down and to stretch is also important for muscle health as well as helping to prevent injuries and to maintain flexibility.

How We Can Help

Our highly trained physiotherapists are able to treat a wide range of health problems including issues relating to the knee. If you are experiencing clicking knees accompanied by pain or inflammation, get in touch today to speak to one of the team. If left untreated, this type of issue could get progressively worse and cause further symptoms. Our physiotherapists can help to prevent this from happening by offering a full assessment and follow up appointments with targeted exercises and stretches, hands on manipulation, pain relief medication and cortisone injections if appropriate, as well as a self-care plan for use at home.


About the Author