Why cant i bend my knee past 90 degrees?

There are several possible reasons why you may not be able to bend your knee past 90 degrees. Knee joint limitations can be due to various factors, including anatomical, physiological, mechanical, and pathological factors. Here are some potential explanations:

1. Anatomical limitations: The anatomy of your knee joint, including the structure and arrangement of bones, ligaments, tendons, and muscles, can affect your range of motion. Some individuals may have inherent anatomical variations that limit their ability to bend their knee past 90 degrees. For example, the shape of the bones or the alignment of the knee joint may not allow for full flexion.
2. Previous injuries: Past injuries to the knee, such as fractures, ligament tears (such as anterior cruciate ligament or ACL tear), meniscus tears, or other traumatic injuries, can result in structural damage to the knee joint. Scar tissue formation, joint instability, or mechanical restrictions from healed injuries can limit the range of motion of the knee joint.
3. Muscle imbalances: Imbalances in the muscles around the knee joint, including the quadriceps, hamstrings, and calf muscles, can affect the ability to fully bend the knee. Weakness, tightness, or imbalances in these muscles can alter the biomechanics of the knee joint, leading to reduced flexibility and limited range of motion.
4. Joint inflammation: Conditions such as arthritis, particularly osteoarthritis, can cause inflammation and damage to the joint tissues, resulting in pain, swelling, and reduced range of motion. Inflammation of the synovial lining of the knee joint, which produces synovial fluid that lubricates the joint, can also affect joint mobility.
5. Scar tissue: Surgery, trauma, or repetitive stress on the knee joint can result in the formation of scar tissue, which can restrict joint mobility and limit the ability to bend the knee fully.
6. Neurological conditions: Certain neurological conditions, such as nerve impingements or nerve damage, can affect the nerves that control the muscles around the knee joint, leading to muscle weakness or loss of coordination, which can impact the range of motion of the knee joint.
7. Pain and fear of movement: Pain in the knee joint or surrounding structures, along with fear of exacerbating the pain or causing further injury, can result in protective muscle guarding or inhibition, leading to limited knee joint mobility.

It is essential to consult a qualified healthcare professional, such as a physician, orthopedic specialist, or physical therapist, for a proper evaluation if you are experiencing limited knee joint mobility. A comprehensive assessment, including a medical history, physical examination, and possibly imaging studies, can help determine the underlying cause of the limitation and guide appropriate treatment options.

Treatment options for limited knee joint mobility depend on the underlying cause and may include:

1. Physical therapy: Targeted exercises and stretches prescribed by a physical therapist can help improve muscle strength, flexibility, and joint mobility. Manual therapy techniques, such as joint mobilizations or soft tissue mobilizations, may also be utilized to address muscle imbalances, joint restrictions, or scar tissue.
2. Medications: Pain-relieving medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs) or corticosteroids, may be prescribed to manage pain and inflammation associated with knee joint limitations due to conditions like arthritis.
3. Rehabilitation after surgery or injury: If the limitation is due to a previous injury or surgery, a structured rehabilitation program under the guidance of a healthcare professional may be recommended to promote healing, restore mobility, and regain strength.
4. Assistive devices: The use of assistive devices such as braces, splints, or crutches may be helpful in managing pain, providing stability, or protecting the knee joint during the healing process.