1. The Knee

2. Bones of the Knee Joint Femur- thigh bone Tibia- shin bone
Patella- knee cap
Fibula

3. Joints of the Knee Patella Femoral Joint
As the knee flexes, the patella slides up and down on the front of the femur. Joint cartilage protects these bone surfaces from friction.
Tibiofemoral Joint
Formed by the femur and the tibia. The joint where the “bending” of the knee occurs.

4. Meniscus
Ring-like structures that fit between the tibia and the femur.
Functions
Cushing of the bones of the knee
Provides stability to the knee

5. Hyaline Cartilage
Joint Cartilage- covers the ends of bones and allows the bones to slide smoothly over one another.

6. Medial Collateral Ligament
The MCL protects the knee from valgus stresses.
MCL
Gives stability to the medial (inside) aspect of the knee.

7. Lateral Collateral Ligament
LCL
Gives stability to the lateral (outside) aspect of the knee.
The LCL protects the knee from varus stresses.

8. Posterior Cruciate Ligament
PCL
Located on the inside of the knee joint.
Protects the tibia from moving backward (posteriorly) under the femur.

9. Anterior Cruciate Ligament
ACL
Keeps the tibia from sliding forward on the femur.
Located between the femur and the tibia.

10. Quadriceps Muscle Group
Made up of 4 muscles
Rectus femoris
Vastus lateralis
Vastus medialis
Vastus intermedius
Performs the Knee Extension movement

11. Hamstring Muscle Group
Made up of 3 Muscles
Biceps femoris
Semitendonosis
Semimembranosus
Performs the Knee Flexion movement

12. Hamstring Strain Also known as a “Pulled Hamstring”
The muscle tissue is either completely or partially torn.
Mechanism of injury:
Hip flexion with knee straight.
Forceful knee flexion
H.S. Tear may occur at the origin of the muscle.

13. Quadriceps Strain Mechanism of injury:
Forceful knee extension; usually during weight bearing
Rapid, forceful knee flexion.

14. Medial Collateral Ligament Sprain / Tear
Mechanism of injury- a valgus stress (bending the knee inward) to the knee. May occur from a blow to the outside of the knee.
Different grades of tears range from a stretching of the ligament to a complete tear.
Common sports injury.

15. Lateral Collateral Ligament Sprain / Tear
Mechanism of Injury: Varus stress on the knee (knee bend from the inside outward).
Not as common as MCL sprains/tears

16. Anterior Cruciate Ligament Tear
Considered a severe injury for an athlete to receive. A complete tear will require surgery, and 9 months of rehab.
Mechanisms of Injury
Foot planted and lower leg rotates.
Direct blow forces the knee into hyperextension.
Direct blow to the back of the tibia, moving the tibia anteriorly.

17. Posterior Cruciate Ligament Tear
Mechanisms of Injury:
Knee is forcefully hyperflexed- falling on bent knee with body weight.
Blow to the anterior part of the tibia with knee bent, forcing the tibia backwards. “Dashboard Injury”

18. Patellar Tendonitis “Jumper’s Knee”
Overuse injury, inflammation of the patellar tendon from repetitive stesses.
The athlete will experience:
Quadriceps weakness
Tenderness over the patellar tendon.

19. Patella-Femoral Pain Syndrome
Also known as “Chondromalacia Patella”
Pain is described underneath or behind the knee cap.
Pain with running, jumping and other repetitive knee movements.
Causes include:
Malalignment of the patella in the femoral groove.
Falling on kneecap.

20. Meniscus Tear Mechanisms include: Twisting Cutting Decelerating
A “popping” sound my occur.
Symptoms include:
Stiffness and swelling
Tenderness in the joint line
Collection of fluid ("water on the knee")
Catching or locking of your knee
Knee buckling

21. Tibiofemoral Dislocation
Femur and Tibia bone are forced out of place.
Considered a medical emergency due to the potential for entrapment of blood vessels and nerves between the disjointed bones.