The human knee is a hinge joint that is comprised of the tibia (shin) and the femur (thigh). The patella, or kneecap, is located in the front of the knee. The knee is supported by four ligaments. Two shock absorbers, each called a meniscus, are found within the knee.
Pain in the knee can be caused by repetitive trauma and strain or by injury. Occasionally it occurs for no apparent reason. When knee pain occurs, you may experience functional limitations that include difficulty walking, rising from sitting, or ascending and descending stairs.
If you experience knee pain, it is important to determine if the pain is acute, sub-acute, or chronic in nature. This can help guide proper diagnosis and treatment.
- Acute pain is usually the most severe and occurs 1-7 days after injury. During this time, you should rest the knee and let the injured structures heal before initiating any motion.
- Sub-acute pain occurs from 2-6 weeks after injury. This is a good time to initiate gentle motion around the knee to help regain mobility.
- Chronic knee pain is pain lasting greater than 8-12 weeks. Knee pain that is chronic should be evaluated by your healthcare provider.
Location of Symptoms
The location of your knee pain can help determine which structures are at fault and can help ensure proper treatment. Remember to check with your physician, physical therapist, or healthcare provider if symptoms are severe or last more than a few weeks.
- Pain in the front of the knee. If you feel pain in the front of the knee, there may be a problem with the tracking and position of the kneecap, often called patellofemoral stress syndrome (PFSS). The kneecap and the tendon between the kneecap and the shin may become inflamed and painful. Pain here usually limits the ability to kneel, ascend or descend stairs, or run and jump.
- Pain on the inside of the knee. If you have pain on the inside portion of the knee there is likely injury to the medial meniscus or medial collateral ligament. These structures are usually injured during athletic activity when the foot is planted on the ground and the body twists over the knee. The medial meniscus is a shock absorber located inside the knee. Occasionally, it suffers from wear and tear or arthritis, and can be damaged with no specific injury.
- Pain on the outside of the knee. Pain on the outside aspect of your knee can be the result of injury to many structures. There is a ligament there that may be injured during athletic activity. Pain here can also be caused by iliotibial band (ITB) stress. The ITB is a thick band of tissue that runs from the outside of your hip to the front of your knee. As it crosses the knee, the ITB can rub abnormally on the knee, and a burning pain can ensue. Also on the outside part of the knee is one of the three hamstring tendons. Strain to this tendon may be a source of knee pain.
- Pain in the back of the knee. Pain in the back of the knee is rare, but can occur. One of the hamstring tendons attaches here, and pain here is likely due to a hamstring strain. Another possible cause of pain here is a Baker's cyst. This is an abnormal swelling of the knee joint that occupies space in the back of the knee and causes pain with excessive bending of the knee.
If you develop acute knee pain, immediately follow the R.I.C.E. principle. R.I.C.E. stands for Rest, Ice, Compression, and Elevation. After a few days of R.I.C.E., you can begin using the leg, only gently. If pain persists for more than 2-3 weeks, you should visit a doctor, physical therapist, or other healthcare provider in order to rule out any major problem and to ensure proper diagnosis and management.
What to Expect From Physical Therapy for Knee Pain
If you are referred to physical therapy for knee pain, the initial visit is important to ensure correct diagnosis and proper management. During this visit, your physical therapist will interview you to gather information about the history of your problem, about the aggravating and relieving factors, and about any past medical history that may contribute the overall problem. From the information gathered during the history, a focused examination will be conducted. The examination may consist of several sections including, but not limited to:
- Gait evaluation. A gait evaluation is an assessment of how you are walking. Physical therapists are trained to notice small changes in the motion around the knee during different phases of walking.
- Palpation. This involves using the hands to touch various structures around the knee to feel for abnormalities or to assess if a structure is painful to touch.
- Range of motion measurements. Range of motion refers to how far the knee is bending or straightening. The physical therapist may use special instruments to measure how your knee is moving to help direct treatment.
- Strength measurements. There are many muscular attachments around the knee and a measurement of strength can help determine if muscular weakness or imbalance is causing your knee pain.
- Girth or swelling measurements. Occasionally, swelling may be present in the knee joint after injury. A physical therapist may measure the amount of swelling to help direct treatment.
- Special tests. Special tests are specific maneuvers performed around the knee to help determine which structure may be at fault and may be causing the problem.
After a focused examination has been completed, your physical therapist can work with you to initiate the correct treatment. It is very important for you to be active and engaged in the program. Often, exercises to help strengthen and improve mobility of the knee will be prescribed. You may be required to perform exercises at home as well.
Remember, if knee pain persists for more than 2-3 weeks or occurs as the result of major trauma, a visit to a physician, physical therapist, or health care provider is recommended.
The knee is a major joint in the body that is responsible for walking, climbing stairs, and rising from a seated position. Pain in the knee can limit one or all of these activities. By keeping the knee joint mobile and strong, problems with knee pain may be avoided and your mobility can be maintained.