A knee sprain occurs when the ligaments within the knee joint are stretched or torn. These ligaments are strong bands of tissue that connect the thighbone (femur) to the shinbone (tibia), providing stability to the knee. An injury to these ligaments can happen due to twisting, direct impact, or excessive weight straining the joint.
Immediate Sensations
When a knee sprain occurs, individuals often experience immediate sensations. Many report hearing or feeling a “pop” or “snap” within the knee joint, which can be accompanied by sudden, sharp pain localized to the knee. After this initial pain, a common feeling is that the knee “gives way” or buckles, leading to an immediate sense of instability.
Developing Symptoms
After the initial impact, a sprained knee develops a range of symptoms. Pain often intensifies over time and can worsen with attempts to move the knee or bear weight. The area around the knee joint begins to swell, which can be localized or spread throughout the joint.
Bruising may also appear hours to days after the injury. The knee can become tender to the touch, particularly over the injured ligament. Stiffness and a reduced range of motion are also common, making it difficult to fully bend or straighten the leg.
Understanding Sprain Severity
The sensation of a knee sprain varies significantly based on its severity, categorized into three grades. A Grade 1 sprain involves a mild overstretching or minor tearing of ligament fibers. Individuals with a Grade 1 sprain may feel mild pain, some tenderness, and slight swelling, but retain the ability to bear weight on the affected leg. The knee feels stable, though there might be a subtle ache.
A Grade 2 sprain indicates a partial tear of the ligament. This level of injury results in more noticeable pain, moderate swelling, and increased tenderness. The knee may feel unstable, especially when attempting to put weight on it, and movement can be painful and limited. There might be a feeling of the knee “giving out” during certain activities.
A Grade 3 sprain represents a complete tear of the ligament. This is accompanied by severe pain at the time of injury, followed by significant swelling and bruising. The knee will feel very unstable, and it may be difficult or impossible to bear any weight on the leg. A complete tear can lead to the joint “buckling” or being completely loose.
When to Seek Medical Attention
It is important to seek medical attention if symptoms suggest a more severe knee sprain. If you are unable to bear weight on the injured leg, or if the pain is intense and debilitating, a professional evaluation is needed. Significant swelling that develops rapidly, or a persistent feeling of instability in the knee, requires medical attention.
You should also consult a healthcare professional if you heard a “pop” at the time of injury, as this can indicate a more serious ligament tear. If your symptoms do not improve with initial self-care measures like rest, ice, compression, and elevation, or if they worsen, it is wise to seek medical advice.