Transcript The Anatomical Knee - Helena Public School District

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
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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
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femur
Insert tibia and fibula
Biceps Femoris
Semitendinosus
Semimebranosus
Gluteus Max,
Semitendonosus,Biceps
femoris, gastrocnemius,
semimembrainosus
Adductors
 Gracilis
– Knee flexion and internal rotation
 Sartorius
– Knee flexion and internal rotation
Abductors
 Illiotibial Band (IT Band)
Gastrocnemius & Soleus
 Plantar flexion
Cartilage
 Two Meniscus
– 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