Lower Limb Anatomy Flashcards
What type of joint is the hip joint?
Synovial, capsule, ball-and-socket between the acetabulum and the femur head
What determines the stability of the hip joint?
- Acetabular depth
- Femur neck length and obliquity
- Capsular ligaments
- Muscles
Draw out the hip and upper thigh muscles (anterior compartment).
Refer to Notion.
Draw out the hip and upper thigh muscles (posterior compartment).
Refer to Notion.
What causes hip flexion?
- Psoas major + iliacus
- Pectineus + rectus femoris + sartorius
What causes hip extension?
- Gluteus maximus
- Hamstrings (long head of biceps femoris, semimembranosus, semitendinosus)
What causes (limited) medial hip rotation?
- Anterior fibers of gluteus medius and minimus
- Tensor fascia latae
What causes (limited) lateral hip rotation?
- Obturator internus and externus
- Piriformis
- Superior / Inferior gemellus
- Quadrator femoris
What causes hip abduction?
- Tensor fascia latae + sartorius
- Gluteus medius + minimus
What causes hip adduction?
- Adductors longus, brevis, magnus + gracilis + pectineus
What supplies blood to the head and neck of femur?
- Medial + Lateral Cx Femoral a.
- Obturator a.
- Superior / Inferior gluteal a., which form trochanteric cruciate anastomosis
What spinal nerve roots are responsible for inward movements of the hip (flexion, adduction, medial rotation?
L2 - L3
What spinal nerve roots are responsible for inward movements of the hip (extension, abduction, lateral rotation?
L4 - L5
Draw out the femur, labelled.
Refer to Notion.
Draw out the tibia and fibula, labelled.
Refer to Notion.
What type of joint is the knee joint?
Modified hinge joint; lateral and medial femorotibial condylar articulation + femoropatellar saddle-type articulation
What determines the stability of the knee joint?
- Depth of articular surfaces (not deep and very incongruent, thus making it weak)
- Muscles
- Ligaments
- Long axes of femur and tibia (face outwards, making it weak)
Where is the patella found?
Embedded in quadriceps tendon
Are the ACL and PCL located inside or outside the knee joint’s synovial capsule?
Outside; the capsule indents inwards to accommodate them.
What ligaments support the knee joint?
- ACruciateL, PCL, fibular CollateralL, tibial CL (aka lateral / medial CL)
- oblique popliteal ligament
- patellar ligament
- Iliotibial tract (when knee is flexed)
Describe the structure of the ACL.
Originates from anterior intercondylar area of tibia (just behind attachment point of medial meniscus), inserts onto the medial surface of lateral femoral condyle.
Poor blood supply.
Describe the structure of the PCL.
Originates from posterior intercondylar area of tibia (behind ACL), inserts onto the anterolateral surface of medial femoral condyle
Describe the function of the ACL.
- Prevents knee hyperextension
- Prevents posterior displacement of femur on tibia
Describe the function of the PCL.
Main stabilising factor of knee
- Prevents knee hyperflexion
- Prevents anterior displacement of femur on tibia (when on ground)
- Prevents posterior displacement of femur on tibia (when off ground)
Describe the structure of the knee menisci.
Medial meniscus is C-shaped and broader, and firmly attached to MCL.
Lateral meniscus is more circular, and more free-moving as it is not attached to LCL.
What causes knee flexion?
- Hamstrings
- Gastrocnemius
What causes knee extension?
- Quadriceps
What causes (limited) medial knee rotation?
- Semimembranosus + Semitendinosus
- Popliteus
What causes (limited) lateral knee rotation?
- Biceps femoris
What spinal nerve roots are responsible for knee flexion?
L5 - S2
What spinal nerve roots are responsible for knee extension?
L2 - L4
What spinal nerve roots are responsible for knee rotation?
L4 - S1
What determines the stability of the ankle joint?
- Congruency of articular surfaces
- Medial and Lateral ligaments (strong)
- Interosseus ligament of the inferior tibiofibular syndesmosis
- Muscles and tendons
What type of joint is the ankle joint?
Synovial hinge joint, between malleoli and lower end of tibia + body of talus
What causes ankle dorsiflexion?
- Tibalis anterior
- Extensor hallucis longus
- Extensor digitorum longus
- Fibularis tertius