The knee is among the most commonly injured areas of the body treated in physical therapy. Commonly knee pain may be caused by injuries such as strains and sprains, fractures, bursitis, meniscus tears, dislocations, ligament or muscle tears, and overuse injuries. It may also be caused by medical conditions such as rheumatoid arthritis, osteoarthritis, gout, and infections. Recently, the number of knee problems has been increasing and is partly due to our increasingly active society. Knee pain has a wide range of causes and each requires different physical therapy plans of care to rehabilitate them.

The primary function of a knee joint is to permit the flexion and extension of the lower leg relative to the thigh while also having to bear most of our body weight while standing.  While the knee has its most significant mobility into flexion and extension it also must twist and rotate to function properly.  The range of motion of the knee is limited by the anatomy of the bones, muscles, and ligaments of the joint.

Symptoms of Knee Pain

The location and severity of knee pain is bound to vary as it depends on the cause of the pain. Accompanying symptoms include:

• Weakness or instability
• Popping, catching, or crunching noises
• Swelling and stiffness
• Redness and warmth to the touch
• Inability to fully straighten or bend the knee

Some common Knee injuries include:

ACL injury: This is a sudden tearing of the anterior cruciate ligament (ACL). ACL connects your shinbone to the thighbone and is commonly injured during sports such as soccer, football, and basketball. Physical therapy is commonly recommended if an ACL injury is sustained.  The first goals of physical therapy is to control pain and welling.  Range of motion and stretching exercises often follow and are routinely accompanied by strength training to restore stability and mobility to the knee while reducing the potential further complication to the injury.

Knee bursitis: A number of knee injuries may cause inflammation in the bursae (the small sacs of fluid that cushion the outside of your knee joint) so that ligaments and tendons glide smoothly over the joint.  These are commonly the result of imbalances where tissues are either too tight or weak and respond readily to physical therapy

Fractures: Bones of the knee and knee cap (patella) are commonly broken during car accidents or falls. People with weak bones due to osteoporosis may sustain a knee fracture by merely stepping wrong.  Once cleared to start physical therapy, treatment to restore mobility and strength are often needed once the joint is no longer immobilized.

Patellar tendinitis: It is the inflammation and irritation of patella tendon. Runners among others who participate in jumping sports are prone to sustaining inflammation in the patellar tendon, which joins the quadriceps muscle and the shinbone.   Physical therapy uses many tools to address this injury including stretching, strength training, soft tissue work (Graston technique), ice, and even orthotics when necessary.

Torn meniscus: The meniscus can be torn if you accidentally twist your knee while bearing some weight on it.  ACL injuries can also accompany a torn meniscus.  Caution must be used in physical therapy when engaging in weight baring exercises to ensure that the meniscus is not damaged further.

Types of Arthritis

There more than 100 known different types of arthritis. Those that commonly affect knee include:

Osteoarthritis: Is the most common type of arthritis, which is also known as degenerative arthritis. It’s a wear-and-tear condition that makes the knee cartilage to deteriorate due to use and age.

Gout (gouty arthritis): This type of arthritis develops when uric acid crystals build up in the joint. The crystals behave like grains in the sand within the joint and results in inflammation and degeneration when the joint is moved.

Rheumatoid arthritis: It is the most debilitating form of autoimmune condition of arthritis that can affect almost any joint in the human body, including the knee. Although it is a chronic disease, it varies in severity and may even come and go.

Pseudo-gout: It is similar to gout, but it is caused by calcium-containing crystals that develop in the joint fluid.

Septic arthritis: Septic arthritis of the occurs with a mild fever when the knee joint is infected, resulting in pain, swelling, and redness.

Risk factors

• Excess weight
• Lack of muscle flexibility or strength
• Previous injury
• Certain sports
• Complications

Not all knee pain is serious however some conditions like osteoarthritis can result in increasing severity in knee damage, pain, and even disability if left untreated by a professional. Similarly, developing a knee injury makes it more likely to experience similar injuries in the future.  Often times a proper treatment plan to restore normal strength and mobility of the knee while also attending to imbalances at the hip and ankle can correct most knee injuries and restore normal function.