Sports Medicine Class Mr. Steve Gross The Master of all Knowledge The Anatomical Knee Sports Medicine Class Mr. Steve Gross The Master of all Knowledge

Knee Diagram

The Knee The knee is the largest joint in the body Bony wise the knee is structurally weak The knee consists of moderate ligament support The muscular support is very strong

Prevention on Knee injuries Strengthen the Quadriceps and the Hamstrings Quads should be at least 70% of Hamstring strength Dominant leg should not be more than 10% stronger than the other leg Full Range of Motion of the knee joint Proper fitting shoes (affect body posture)

Femur Longest and strongest bone of the body Sits on top of a smaller tibia Joint slides even in uneventful situations Minimal rotation of femur on the tibia Distal femur is convex Proximal tibia is concave

Tibia Weight bearing bone of the lower leg

Fibula Non-weight bearing bone of the lower leg Serves as an anchor for muscle attachment Articulates only with the tibia

Patella Enclosed by patellar tendon Moves up and own in front of the knee joint Protection for the knee joint

Ligaments Medial Collateral Ligament (MCL) Lateral Collateral Ligament (LCL) Anterior Cruciate Ligament (ACL) Posterior Cruciate Ligament (PCL)

Medial Collateral Ligament Secures femur to tibia Also connects to the cartilage Broad and flat ligament Prevents against a valgus force

Lateral Collateral Ligament Cord-like Ligament Does not attach to Meniscus Prevent against a varus force

Anterior Cruciate Ligament Attaches to the anterior portion of the tibia Attaches to the posterior portion of the femur Prevents internal & external rotation & posterior slide of femur

Posterior Cruciate Ligament Attaches to the posterior portion of the tibia and the anterior portion of the femur Prevents forward slide internal rotation and hyperextension of the knee

Cruciate Ligaments Cruciate ligaments make an X in the center of the joint preventing anterior and posterior movement of the femur on the tibia

Muscles of the Knee The knee joint has excellent muscular support from the quadriceps, hamstrings, adductors and abductors

Quadriceps Extend lower leg Insert on tibial tuberosity Rectus Femoris Vastus Medialis Vastus Lateralis Vastus Intermedius

Hamstring Muscles Flex the lower leg Controls rotation Origin is the pelvis and femur Insert tibia and fibula Biceps Femoris Semitendinosus Semimebranosus Gluteus Max, Semitendonosus,Biceps femoris, gastrocnemius, semimembrainosus

Adductors Gracilis Knee flexion and internal rotation Sartorius

Abductors Illiotibial Band (IT Band)

Gastrocnemius & Soleus Plantar flexion

Cartilage Two Meniscus Sit on top of tibia in the concave indentation Fibrous cartilage medial and lateral Medial is a C shaped cartilage Lateral is an O shaped cartilage Sit on top of tibia in the concave indentation Provide shock absorption Reduce friction

Meniscal Tears

Bursa Fluid filled sacs Cushion against friction With increased friction bursa fluid is emitted to reduce the friction

Synovial Membrane Closed sac lining the inside of the knee joint Lubricates tendons, ligaments, and bones

Mechanism of knee injuries Contusions Sprain Strain Fractures overuse

Contusions Direct blow Fall Contusions common in BB,VB,WR,& FB

Ligament Sprains Blow from any direction Compounded when the foot is planted Most common is the MCL

Torsion Injuries Foot planted and the body twists Torsion injuries damage Ligaments and Meniscus Most common is the ACL

Chondramalacia The centering of the patella in the trochlear groove is related to the strength of the vastus medialis obliqus (a part of the vastus medialis muscle) and the medial patello-femoral ligaments which pulls the patella towards the opposite knee while the vastus lateralis and lateral patello-femoral ligaments pull the knee cap towards the outside (lateral) aspect of the knee. When all of these forces are in proper alignment, the patella is centered in the trochlear groove of the femur.