*Knee Anatomy ----

The knee joint is made up of three bones and a variety of ligaments

  • The femur (the thigh bone)
  • The tibia (the shin bone)
  • The patella (the kneecap)

A ligament is defined as a fibrous tissue that connects bones to other bones. Several muscles and ligaments control the motion of the knee and protect it from damage at the same time. Ligaments of the knee make sure that the weight that is transmitted through the knee joint is centered within the joint minimizing the amount of wear and tear on the cartilage inside the knee.

The four major ligaments in the knee are:
  • Anterior Cruciate Ligament (ACL)
  • Posterior Cruciate Ligament (PCL)
  • Medial Collateral Ligament (MCL)
  • Lateral Collateral Ligament (LCL)
The medial and lateral collateral ligaments, which are located on either side of the knee, stabilize the knee from side-to-side.
The anterior cruciate ligament (ACL) and a posterior cruciate ligament (PCL) are in the center of the knee joint and form a cross. These ligaments function to stabilize the knee from front-to-back during normal and athletic activities.

The medial meniscus and the lateral meniscus, which is also know as cartilage, are two shock absorbers in your knee on either side of the joint between the cartilage surfaces of the femur and the tibia. They help minimize the amount of stress on the articular cartilage. The combination of the menisci and the surface cartilage in your knee produces a nearly frictionless gliding surface.

Movement of the knee

The main muscles that move the knee joint are the quadricep and hamstring muscles. The quadriceps attaches to the patella, and the patellar tendon connects this muscle to the front of the tibia. When the quadricep muscles contract the knee extends. In contrast, when the hamstring muscles contract, they pull the knee into flexion.

Knee Injuries

Knee injuries have are very common. One of the main reasons they're so common is that with so many teens playing sports, knees can be overused, leading to several types of injuries, some of which can't be repaired.
The common causes for injuries are:
  • overuse (from repetitive motions)
  • sudden stops or twists
  • direct blows to the knee
The different knee injuries include:
  1. Sprains
  2. Strains
  3. Tendonitis
  4. Menisci Tears
  5. Fractures and dislocation
  6. Cartilage injuries

A sprain means you've stretched or torn a ligament so in the knee it is usually the ACL or MCL. The most serious sprains involve complete tears of one or more of the knee ligaments. Symptoms of knee sprains include:
  • a popping or snapping sound in the knee at the time of injury
  • pain that seems to come from within the knee, especially with movement
  • not being able to put any weight on that leg
  • swelling
  • fluid behind the kneecap
  • the knee feels loose or unstable
A strain means you've partially or completely torn a muscle or tendon. With knee strains, you may feel symptoms similar to a sprain and may see bruises around the injured area.
Tendinitis happens when a tendon gets irritated or inflamed. It is often caused by overuse. A person with tendinitis might have pain or tenderness when walking, or when bending, extending, or lifting a leg.
Meniscal Tears
Damage to the menisci is a really common sports injury, especially in sports where sudden changes in speed or side-to-side movements can cause them to tear. Meniscal injuries often occur together with severe sprains, especially those involving the ACL. Meniscal injuries can cause tenderness, tightness, and swelling around the front of the knee.
Fractures and Dislocations
A fracture is a cracked, broken, or shattered bone. You may have trouble moving that bone and it's likely there's a lot of pain. Patellar dislocation happens when the patella (the kneecap) is knocked off to the side of the knee joint, by twisting or some kind of impact. Sometimes it will go back to its normal position by itself, but usually it will need to be put back into place by a doctor. Symptoms include swelling and a lot of pain at the front of your knee. There will usually be an abnormal bulge on the side of your knee, and you may be unable to walk.
Cartilage Injuries
Sometimes a small piece of bone or cartilage softens or breaks off from the end of a bone, causing long-term knee pain. This is called osteochondritis dessicans (OCD). Symptoms of OCD include pain, swelling, an inability to extend the leg, and stiffness, catching, or popping sensations with knee movement. Chondromalacia happens when the cartilage in the knee joint softens because of injury, muscle weakness, or overuse, and the patella and the thighbone may rub together. This causes pain and aching, especially when a person walks up stairs or hills. Treatment may involve surgery

My sources included:
"Dr. Scots Knee Book" by Dr. W. Norman Scott
"Knee Health Problems, Prevention and Cure" by Vivian Grisogono

Knee Rehabilitation

Objectives of Rehabilitation:
  • Protecting the joint from further mechanical injury with the use of braces, crutches, etc.
  • Reducing internal swelling to allow proper mobilization and to prevent internal blood clots from forming into scar tissue
  • Maintaining muscle responsiveness
  • Restoring range of motion
  • Rebuilding muscle strength to restore function and also to protect joint from further injury

Physical therapy plays an important role in treating and rehabilitating the knee after an injury occurs. There is no quick cure for a knee injury, they take time to heal.

How Physical Therapy Can Help Knee Problems

  • Steps taken by a Physical Therapist:leg-stretch.gif
    • Evaluation: The Physical Therapist will first talk with the patient and perform a thorough physical evaluation to determine the knees condition and any predisposing factors.
    • Therapy: A treatment regimen is then planned suited to the patient's individual condition. The purpose of this regimen is to begin working to restore motion and muscular performance.
    • Teaching: A home program is designed by the Physical Therapist so the patient can continue their therapy on their own at home.
    • Aftercare: The whole goal of physical therapy is to return the patient back to normal life as soon as possible, with the skills and knowledge they need in order to prevent re-injury.

  • The treatment plan designed by a Physical Therapist would include these two main components:
    • Maximum protection, a series of exercises designed to help motion. Activities in this phase might include water walking, swimming, leg presses, and mini-squats.
    • Return to function and maintenance, an exercise sequence to restore strength. These activities are a gradual return to normal activities using exercises that simulate the knee stresses of your normal activities


Treatment of Mild Knee Injuries

  • A common method used is "R.I.C.E." which stands for Rest, Ice, Compression, Elevation
    • Rest the knee by staying off of it, or walking only with the use of crutches
    • Apply ice to the injury to control the swelling
    • Use a compressive elastic bandage applied snug, but loose enough to not cause pain
    • Keep the knee elevated, raised higher then your heart

Treatment of Patellar Tendinitis


  • The pain associated with patellar tendinitis can vary from patient to patient depending on the severity of the condition.
  • In each case the treatment is essentially the same but the recovery time will vary.
  • Treatment is usually limited to the use of R.I.C.E. and occasionally physical therapy.
  • The most critical step is to identify the activities that irritate the tendon and modify or eliminate them.
  • Rest is required to allow the tendon to heal and irritation to subside. This may take a couple days or several weeks.
  • Ice packs around the knee are used to reduce pain and swelling. Usually 20-30 minutes 4-6 times a day until the swelling subsides.
  • Strengthening the quadriceps helps to equally distribute the forces across the patella and take pressure off the patellar tendon.
  • Hamstring stretching is also important to take pressure off the anterior structures of the knee.
  • Neoprene sleeves can help to decrease or disperse the forces on the patella once the inflammation is controlled and the patient can begin mild exercise.


The hamstring stretch can be done right away. After pain has reduced, the quadriceps stretch can be done and begin to strengthen the thigh muscles with the remainder of the exercises.

Treatment of Meniscal Tearsmeniscustears.jpg

  • Initial treatment consists of rest and refraining from activities that aggravate the condition. Any actions that involve pounding of the knee, such as running or jumping should be avoided.
  • A meniscal tear that is painful with normal everyday activities should be treated surgically.
  • Surgery is performed arthroscopically to repair the torn or damaged cartilage.
  • After surgery the patient will usually be non-weight bearing for one month to allow the meniscus to heal. The movement of the femoral heads over the tear could disrupt the healing process.
  • Early rehabilitation physical therapy focuses on mobilization of the knee joint and quad and hamstring strength.


My sources: