The knee is a joint, meaning it sits between an area where the bones connect. As the largest joint in the body, the knees provide stability and flexibility, which allow the legs to bend, swivel and straighten, according to KidsHealth.org. The knee itself is in the middle of three bones: the tibia, femur and patella. Muscles, tendons and ligaments, as well as cartilage for cushioning, surround the region. Knee joint pain symptoms can indicate an underlying condition that requires diagnosis by a medical professional.
Swelling and Stiffness
Knee joint pain may first begin or accompany swelling and stiffness. For example, when a sprain---meaning a torn ligament---occurs, the surrounding tissue will inflame, causing swelling around the knee and a general stiffness that makes flexing it difficult. Pain can come from within the knee, specifically during movement, which can indicate a sprain ranging in severity. The most serious sprains involve the complete tearing of one or more knee ligaments, KidsHealth.org states. Additionally, MayoClinic.com notes that the location and severity of the knee pain can vary and primarily depends on the cause of the knee joint pain.
Popping or Crunching Noises
Popping or crunching noises may appear during the time of an injury or during movement, MayoClinic.com reports. This sound is due to the damage to the anterior cruciate ligament, or ACL. The popping and crunching may not be serious if there isn't pain associated with it. However, knee joint pain with popping or crunching noises usually indicates that the cartilage specific to the crunching noises is gone, resulting in bone-to-bone interaction in the knee. In the long term, this can cause recurring pain, persistent swelling and popping sensation. Treatment usually requires resting the knee, wearing a cast or even surgery.
Locking
Locking of the knee results in an inability to full straighten out the joint, according to MayoClinic.com. This lock often accompanies knee joint pain, especially in movements from side to side, and usually indicates a meniscus tear. Initially, the tear may be minor, causing minor pain during movement. However, if repeated irritation occurs or persistent injury, the tear can become exceedingly severe, causing fluid to lodge behind the knee, called effusion. This type of knee joint pain is common in sports-related injuries.
