Why Stiff Knees Happen - Injury Overview

A stiff knee and knee pain should be taken seriously because of the effects it can have on your quality of life. Knee stiffness can even cause us to miss family gatherings and important events if severe enough. Stiff knees can plague people of any age, but it is more common among older people. Keep reading to better understand how stiff, achy knees can develop and to learn the best ways to treat your knee stiffness.

Understanding Knee Stiffness

Understanding knee anatomy will give us a clue as to what might be causing stiffness. Our knees are stabilized by two pairs of ligaments: the medial and lateral collateral ligaments and the posterior and anterior cruciate ligaments. Plus, there are also two pieces of cartilage, called menisci, which act as a cushion to protect the bones with movement. Additionally, there are other stabilizing connective tissues like the joint capsule itself, the kneecap, and other various large stabilizing muscles that cross the knee joint. Any of these parts of the knee may be damaged or imbalanced, causing a stiff knee and restricted movement.

Stiff Knee: No Pain

Sometimes, stiffness in the knee does not come with pain, although there could be some swelling that limits range of motion. If you are an athlete or runner, you may not notice the pain at first. However, if stiffness is ignored it will most likely worsen over time because of its effects on other local tissues that have to adapt.

What Causes Stiff Knees?

There are several causes of knee pain and stiffness, but they are generally organized into three categories:

Stiff Knee After Injury

The knee changes the way it moves if one of its structures is damaged. The most common injuries that can lead to knee stiffness include:

Stiff Knee After Prolonged Positions

Stiff Knees in the Morning

Like any position you spend a lot of time in, it can lead to stiffness. Our body’s like to move so that blood is flowing and tissues are supple. Sleep is definitely a time when knee stiffness can be exacerbated. Whether you sleep with your knee bent or straight, it can feel hard to move in the opposite direction in the morning until you get moving and warm your joints up.

Stiff Knees from Running

Many runners suffer from stiff knees before, during, or after their workouts. This can be due to overuse, muscle imbalances, or an underlying injury. Determining what part of your run is making your knees stiff can help you reduce this common issue.

Stiff Knee Joints Due to Medical Conditions

A number of medical conditions can cause inflammation that result in stiff knee joints. The most common are:

Rare Causes

There are a few rare causes of a stiff knee that are potentially life-threatening and require immediate medical attention. However, it’s important to keep in mind that these are very rare and highly unlikely.

Symptoms of Stiffness in Knee

You use your legs every day, so you’ll know when your knees aren’t moving or feeling right. The following are other symptoms commonly associated with knee stiffness.

• Redness
• Knee joint pain when bending or straightening
• Knee swelling/inflammation
• Stiff knees in the morning
• Knee instability
• Stiff knees with prolonged sitting or standing
• Muscle weakness
• Burning pain or aching in other joints
• Cracking or popping in the joints with movement
• Locking of the joint with specific positions

Thankfully, most of these symptoms can subside with time and appropriate treatment. However, ff you experience any of the following symptoms, talk to your doctor immediately for medical advice:

• Fever
• Loss of sensation in the lower leg
• Loss of lower leg coordination or ability to balance
• Extreme instability
• Excessive swelling
• Severe or stabbing pain
• Bleeding
• Complete loss of range of motion
• Deformity of the knee or other areas of the leg 

Diagnosing and Treating Knee Pain and Stiffness

Direct injuries, medical conditions, and infections that disturb the normal structure of the joint are all causes of knee stiffness and pain and make the surrounding tissues more sensitive. Speak to your orthopedic doctor for a comprehensive assessment. Apart from a thorough physical examination, you may need to undergo imaging tests, such as an X-ray, a CT scan, or an MRI. An accurate diagnosis is necessary to determine the correct treatment for stiff knee joints.

If neglected or improperly treated, stiffness in the back of knee joints can get worse and may put you at risk of permanent joint immobility and a decrease in your overall quality of life.

What treatment options are right for your stiff knees will be dependent on the underlying cause, your preferences, fitness level, and more. In general, a focus on restoring joint range of motion and muscle balance is important. This can be done with exercise training, inflammation management (with modalities and drugs like ibuprofen) physical therapy, appropriate use of knee braces or sleeves, and beyond. Once you have an accurate diagnosis, the rest will fall into place for treatment so that you can start feeling your best.