Hinge joint at the articulation (point of contact) of 3 bones

Stabilized by 4 major ligaments, cartilage, and strong musculature

Knee also able to rotate

3 bones form the knee joint◦ Femur, tibia, fibula

Primary movement occurs at the POC of the tibia and femur

Patella = sesamoid (floating bone) As the knee flexes and extends, the patella

glides up and down on the front of the femur

4 primary knee ligaments Medial collateral ligament (MCL)-provides

stability to the inside (medial) aspect of knee

Lateral collateral ligament (LCL)-helps stabilize outside (lateral) aspect

Anterior cruciate ligament (ACL)-keeps tibia from moving forward on the femur

Posterior cruciate ligament (PCL)-prevents tibia from moving backward on femur

*PCL and ACL pass thru the middle of the knee joint and cross each other

Ends of tibia and femur are covered and cushioned by pieces of tough cartilage tissue called menisci

Without menisci, tibia and femur would rub against each other, causing the bones to wear down quickly

Menisci also help stabilize the joint

Provide movement and stability Primary muscles include hamstring group

and quadricep group Knee extension primarily performed by the

quads (4 muscles) Knee flexion performed by the hamstrings

(3 muscles)

Ligament sprains are the most common injuries at the knee

Athletes should develop strength in the muscles around the knee

If athlete has problems with knees, ATC should examine leg structure to determine if he/she has genu valgus (knock-knees) or genu varus (bowlegs)

Knee vulnerable to injuries due to exposure to many forces

Ligaments extremely vulnerable but tendon and bone injuries do occur

ACL-athlete often disabled, complaining of knee giving way, collapsing, and popping

Often the most serious and most frequently surgically reconstructed

Often injured as athlete attempts to change directions quickly and twists lower leg

May hear a popping sound Immediate treatment includes PRICE, knee

immobilizer, and crutches Rehab focuses on strengthening hamstrings to

help stabilize tibia

Frequently injured when athlete falls and bent knee bears full weight, when knee is forcefully hyperflexed or blow is delivered to the front of the tibia

Often little swelling Treatment includes PRICE and referral to

physican Rehab focuses on strengthening the quads

and regaining full function

Injured when athlete receives a blow to the outside of the knee

Treatment includes PRICE Moderate to severe MCL needs an

immobilizer Rehab focuses on strengthening the

muscles that cross the medial aspect of the knee

Mild MCL sprain-medial joint line pain, little if any swelling, no joint laxity, full flexion and extension

Moderate MCL sprain-mild swelling, discomfort, some joint laxity

Severe MCL sprain-moderate or severe swelling, loss of function, great deal of joint laxity

Occur less frequently than MCL injuries Symptoms are similar except discomfort is

at the lateral aspect Treatment same as MCL Rehab focuses on strengthening the lateral

thigh muscles and hamstrings

Patellar tendinitis-overuse disorder characterized by quad weakness and tenderness over patellar tendon

Treatment will attempt to control inflammation (apply ice, modify activity level)

Rehab will address flexibility problems or weakness of the leg

Set of symptoms that include pain and discomfort around the patella

As the knee bends, instead of riding smoothly, the patella is grated across the femur, causing cartilage on the back of the patella to soften or wear away

Athlete reports a grinding sensation with flexion and extension

Grinding can be felt by placing hand over patella

Treatment involves correcting patellar tracking problems

Patella forced to the lateral aspect of the knee

Occurs when knee is bent and forced to twist inward

Athlete is often in distress Only physician should reduce a dislocated

patella Treatment involves immobilizing the knee