The Knee Joint and Leg Flashcards
What are the epicondyles of the femur for?
muscle attachment
What muscle attaches to the adductor tubercle of the femur?
adductor magnus
What are condylar surfaces covered in?
myelin cartilage
What do the condyles of the femur articulate with?
tibia
What is the groove between femoral condyles is…
intercondylar groove/fossa
What bony landmark does the quadiceps attach to for the extension of the knee?
quadriceps
What type of bone is a patella?
sesamoid
What tendon does the patella sit in?
quadriceps tendon
What bony landmark does the patella sit on?
patella surface of femur
Classify the knee joint
synovial, biaxial, hinge joint (modified hinge joint as it can slightly rotate when locking)
What are the movements of the knee
what axis/plane do these movements occur on?
flexion and extension
transverse axis
What does locking of the knee bone allow?
muscles to relax as bones are supporting weight
What does the bursa in the knee prevent?
tendons rubbing on bone
What condyle of the femur is larger?
medial larger than lateral
Describe the menisci of the knee
Lateral almost circular, medial is a crescent shape.
How is the menisci held in place?
anchored down by ligaments to joint surfaces of the tibia
What is the function of the menisci?
shock absorption and support
True or false, cruciate ligaments lie between the menisci
true
What are the two cruciate ligaments?
Anterior and posterior (ACL and PCL)
- named in relation to their location on the tibia
What type of ligaments are the ACL and PCL?
intracapsular
What does the ACL limit?
medial rotation and anterior slide of the tibia on femur
What does the PCL limit?
medial rotation and posterior slide of tibia on femur
What are the two extracapsular ligaments that support the knee?
Fibular (lateral) collateral and Tibia (medial) collateral ligaments (LCL and MCL)
Describe the LCL
long, thin, cord-like ligament that limits extension and prevents adduction
Describe the MCL
flat band that limits extension and prevents abduction
What is the process of locking the knee?
- Lateral side of joint completes motion sooner than medial side as it is smaller
- Movement continues in the medial compartment results in slight rotation of the joint (if tibia fixed, femur rotates medially)
- Takes the knee into a locked position
What is beneficial about locking the knee?
no muscle effort required to hold up body
What makes locking the knee a stable position?
Maximum contact between joint surfaces, tibial tubercles logged in the intercondylar notch, ligaments tense = stable joint position
What is unique about the relationship between muscles crossing the joint surface and their action?
- anterior = extension
- posterior = flexion
due to the nature of the hinge (opposite of elbow hinge)
List flexors of the knee
- hamstrings: biceps femoris, semimembranosus and semitendinosus
What are the hamstrings innervates by?
sciatic nerve
Describe the passage of the sciatic nerve
- comes out of greater sciatic notch
- travels down posterior aspect of leg
- travels through popliteal fossa
- supplies most of the lower limb
List the extensors of the knee
quadriceps: rectus femoris, vastus lateralis, vastus medialis and vastus intermedialis
What is the attachments of rectus femoris?
ilium to quadriceps tendon
What quadriceps muscle is the deepest?
vastus medialis (under rectus femoris)
What is the general attachment of the quadriceps muscles?
femur to quadriceps tendon to tibial tuberosity
What are the quadriceps innervated by?
femoral nerve
Describe the muscles engaged during the different stages of gait.
- Heel strike – gluteus maximus, posterior capsule and tibialis anterior
- Loading response – quadriceps femoris
- Midstance – triceps surae
- Terminal stance (heel off) – triceps surae
- Pre-swing (toe off) – deep plantar flexors, flexors of toes, intrinsic foot muscles, rectus femoris
- Initial and Mid-swing – contralateral abductors of the hip, iliopsoas and rectus femoris
- Terminal swing - hamstrings, quadriceps femoris and tibialis anterior
What is the lumbosacral plexus?
large plexus of nerves that supplies the lower limb
What are the two main branches of the lumbosacral plexus?
tibial and common perineal (fibular) - supplies posterior of thigh and everything from the knee down
What is the anterior thigh supplied by?
femoral nerve
What does the obturator nerve supply?
adductors and medial aspect
What muscles does the tibial nerve supply?
gastrocnemius, soleus, tibialis posterior, flexor hallucis longus & flexor digitorum longus
What muscles does the superficial peroneal supply?
peroneus longus and brevis
What muscles does the deep peroneal supply?
tibialis anterior, extensor digitorum longus, extensor hallucis longus and peroneus tertius
