What Causes Swelling

By Ben Benjamin, PhD

Question: True or false: Visible swelling occurs when tendons and ligaments are injured.

Answer: False

Although there is a bit of internal swelling with tendinitis, major or visible swelling does not occur when most tendons are injured.

Swelling occurs when ligaments are injured because the ligaments are intimately connected with the functioning of the joints. Ligaments hold our joints together, helping to maintain the structural integrity of the skeletal system. When a ligament is strained, the synovial membrane of the joint where the ligament is located is "told" by the brain to produce more fluid than is required for proper functioning. This increase in synovial fluid causes the joint to swell. This swelling is our body's way of sending us a strong and important message. The body is saying, "Don't move me too quickly or too vigorously, or I will send pain signals to remind you that I need to rest in order to heal."

Therefore, when you see a client who has a swollen ankle, knee, wrist or finger, it's not a tendon-related problem. These symptoms usually mean the joint and its surrounding ligaments are injured. Besides sending a message to the injured person, the swelling is also sends a message to the practitioner. It tells you where to look for the injury.

For instance, when the medial collateral ligament at the inner portion of the knee is sprained, a message is sent to the joint's membrane to produce fluid, causing the joint to swell. This swelling limits the knee joint's ability to bear weight, flex and extend. The body therefore is forced to rest to allow healing to occur.

Sometimes this system works; the knee heals with minimal scar tissue, and full function is restored. Unfortunately, this healing cycle often breaks down. When this happens, the body lays down disorganized and malformed scar tissue, binding inappropriate tissues together so that healing is impaired for a long time, or permanently. However, if appropriate hands-on or medical treatment is correctly applied, the excessive adhesive scar tissue is eliminated in the ligament, and the swelling, usually referred to as a traumatic arthritis, disappears by itself.