Knee Pain Explained

person with knee pain grasping knee

Knee pain is a fairly common issue, with approximately 1 in 4 American adults experiencing knee pain affecting the function of the knee. The prevalence of knee pain has increased over the past 20 years, with osteoarthritis being the most common cause in people over the age of 50. When knee pain occurs as a result of injury, it is most often associated with knee cartilage tears. These injuries can result from direct blows or sudden movements that cause the joint to go beyond its normal range of movement. Knee pain can cause difficulty performing activities such as walking, rising from a chair, climbing stairs, or playing sports. Physical therapists have specific training to help diagnose and treat knee pain, and help individuals return to their normal activities without pain or limitation.

What is Knee Pain?

The knee joint is a hinge joint that connects the tibia (shin bone), and the femur (thigh bone) at the patella (knee cap). There are 4 main ligaments that support the knee joint. They are the anterior cruciate ligament (ACL); posterior cruciate ligament (PCL); medial collateral ligament (MCL); and lateral collateral ligament (LCL). There are also 2 rings of cartilage that act as shock absorbers in the knee, called the medial and lateral meniscus.


The most common cause of knee pain is osteoarthritis, a condition that occurs when the cartilage that protects the inside surfaces of the tibia and femur bones called articular cartilage gradually wears away, resulting in pain and swelling in the knee.

How Does it Feel?

Knee pain can occur suddenly for no apparent reason or develop slowly, as the result of repetitive trauma. If you are not sure whether you are experiencing pain or soreness, read our article explaining the differences in soreness vs pain. The pain may occur in different areas depending on what structures in the knee are involved. Below is a general breakdown of the areas in which knee pain may occur and the structures of the knee that may be involved:

  • Anterior knee pain, also referred to as patellofemoral pain, is pain around the kneecap (patella) in front of the knee. This pain is a result of the kneecap shifting out of position. This condition commonly affects younger females, and may be due to overuse injury. Pain often occurs when performing activities like squats or stair-climbing.
  • Lateral knee pain occurs on the outside of the knee. It is a type of overuse injury that commonly occurs when the tendon called the iliotibial band (ITB) becomes irritated. Activities such as climbing stairs, walking or running are often causes of lateral knee pain.
  • Medial knee pain occurs along the inside of the knee when the MCL or the medial meniscus become irritated due to direct injury or overuse. Squatting, walking up or down an incline, or going down stairs is often the cause of medial knee pain.
  • Pain caused by a ligament tear may result from a direct blow to the knee, or when twisting or pivoting the knee while the foot is planted on the ground. Immediate pain and swelling usually occur, and the knee may feel unstable—like it will “give out”—when an individual attempts to put weight on the involved leg.
  • Pain caused by osteoarthritis may occur anywhere in the knee where cartilage has broken down. This type of knee pain may begin as mild and progressively worsen. It can become increasingly difficult to walk long distances, fully bend and straighten the knee, climb stairs, or squat to sit in a chair. The knee also may swell intermittently with increased activity.

If any of these sound like pain you are experiencing, give us a call at (303) 494-4100.

How Does a Physical Therapist Diagnose Knee Pain?

Your physical therapist will perform an evaluation that will start with discussing your medical history and your symptoms. Next, your therapist will ask questions to determine where your pain is located or if you sustained any trauma or injury to the knee. Your therapist will then make a diagnosis based on your symptoms, medical history, and an examination. After this, your physician may order an X-ray and/or an MRI to complete the diagnosis.  Your physical therapist will perform tests to find out if you have:

  • Limited range of motion in the knee.
  • Pain in the knee with certain movements.
  • Weakness in the muscles around your hip, knee, or ankle.
  • Limited flexibility in your hip, knee, or ankle.
  • Difficulty performing activities, such as rising from a chair or climbing stairs.
  • Problems with your balance or coordination.
  • Difficulty controlling the knee during certain activities.


How Can a Physical Therapist Help?

Based on the findings of your evaluation, your physical therapist will develop a customized rehabilitation program to ensure a safe return to your desired activities. Some general treatment techniques may include:

  • Pain management
    • Your therapist may provide treatments using different “modalities” such as ultrasound, or electrical stimulation to help decrease pain and swelling.
  • Manual therapy.
    • Your therapist will apply manual (hands-on) therapy to gently guide movement of the knee area to restore joint and tissue mobility.
  • Therapeutic exercises.
    • Your physical therapist will prescribe specific strengthening, flexibility, and endurance exercises to address your specific needs and goals.
  • Functional exercises.
    • You will learn individualized exercises designed to help you return to your home, work, and sport activities. These also may include balance and coordination exercises.
  • Self-care instruction.
    • Your physical therapist will teach you ways to manage your pain at home, and design a safe and effective home-exercise program based on your specific condition. You can continue these exercises long after your formal physical therapy sessions have ended. You will also learn how to avoid placing unnecessary forces on the knee during your daily activities.


How Can a Physical Therapist Help Before & After Surgery?

Your physical therapist and your surgeon will be able to tell you how active you should be. This will depend on the type of knee surgery (such as total knee replacement) you undergo. Your therapist and surgeon also might suggest participating in physical therapy before your surgery to increase your strength and motion. This can sometimes help with recovery after surgery.

Following surgery, your physical therapist will design a personalized rehabilitation program for you. This program will help you gain the strength, movement, and endurance you need to return to performing the daily activities you did before.


Can this Injury or Condition be Prevented?

To help reduce knee pain, it is important to perform regular safe exercise, get enough rest, and eat healthy foods. Weight management is important for maintaining healthy knee function, as increased body weight puts extra pressure on all the joints, including the knees. Ideally, individuals of all ages should regularly perform some form of flexibility, strength, and heart-conditioning exercises.

Athletes should also perform appropriate warm-up exercises and stretches on a daily basis and before beginning physical activity.

CAUTION: If any exercise or activity provokes knee pain, seek professional help before the symptoms worsen.




Compliments of APTA: Move Forward-Physical Therapy Brings Motion to Life