Lower Limb Flashcards
What are the functions of the lower limb?
- Support the body weight
- Locomotion (bipedal gait)
What are the regions of the lower limb?
- Gluteal region (to hip joint)
- Anterior thigh (to knee joint)
- Posterior thigh (gluteal region to knee joint)
- Leg (knee to ankle)
- Foot
What is another name for the hip joint?
Acetabulofemoral joint
What are the bones of the hip/ pelvis?
- Ilium (iliac crest, sacrum)
- Pubis (pubic symphysis)
- Ischium (ischial tuberosity- part that you sit on)
What are the features of the hip bone?
- Iliac crest
- Gluteal lines (anterior, posterior, inferior)
- (Iliac and ischial) spine
- (Greater/ lesser) sciatic notch
- Ramus of ischium and pubis
- Obturator foreamen
- Acetabulum
What are the features of the proximal end of the femur?
- Head
- Pit for ligament of femur head
- Neck, narrow
- Tubercles (quadrate, gluteal)
- Trochanter (greater, lesser)
- Intertrochanteric line (anterior) and crest (posterior)
- Pectineal line
- Spiral line
Describe the features of the Acetabulum
- Acetabular foreamen
- Acetabular fossa
- Obturator foreamen
- Acetabular notch (gap in socket)
- Transverse acetabular ligament (fills acetabular notch)- full circle
- Lunate surface
- Acetabular labrum= Fibrocartilaginous rim, deepens socket
Describe the capsule and ligaments of the hip joint
Anterior: -Iliofemoral LIGAMENT= strongest, horizontal and vertical band, Y ligament -Ligament of the head of the femur (ligamentum teres) -Pubofemoral LIGAMENT Posterior: -Capsule -Acetabular labrum -Intertrochanteric line -Ischiofemoral LIGAMENT -Transverse acetabulum ligament -Ligamentum teres
How does the centre of gravity affect the ligaments of the hip joint?
The iliofemoral ligament is tight during standing. No muscles are required to keep your hip stable, so you can stand for a long time.
Center of gravity posterior to hip joint
=Twist in posterior to anterior direction
=Unwind in flexion so reduces stability
What are the movements at the hip joint and muscles acting on the hip for these movements?
-Internal rotation= medial
-External rotation= lateral
=Piriformis (sciatic nerve exits pelvis at greater sciatic foramen and travels underneath piriformis)
=Quadratus femoris (square like shape)
=Gemelli(superior and inferior)
=Obturator Internus and Externus
What are the muscles acting in the hip (flexors)?
-Illiopsoas (Ant.) =Two muscles: psoas major and iliacus =Join and travel across hip joint to insert onto lesser trochanter of femur -Pectineus (Med.) =Medial compartment -Sartorios (Ant.) =Long thin muscles crossing two joints -Rectus femoris (Ant.) =One of 4 quadriceps muscles (only one to cross hip joint)
What are the muscles acting on the hip (extensors)?
-Hamstrings (posterior compartment of thigh):
=Biceps Femoris (long and short heads)
=Semitendinosus (obvious long tendon insertion)
=Semimembranosus (covered by membrane)
-Gluteus maximus (biggest and most superficial of gluteal muscles),
What are the muscles acting on the hip (abductors)?
- Gluteus Medius (deep to gluteus maximus)
- Gluteus minimus (deep to gluteus minimus)
What are the muscles acting on the hip (adductors)?
Medial compartment of thigh
- Adductor longus (more superficial than Brevis)
- Gracilis (most medial, very long thin strap like muscle)
- Adductor Brevis (Brevis= short)
- Adductor Magnus (biggest adductor muscle, attaches onto whole aspect of femur, two portions: adductor and hamstring)
What are the bones of the knee region?
- Femur
- Tibia
- Fibula
- Patella
What are the bones of the knee joint?
- Femur
- Tibia
- Patella
What are the bones of the proximal tibiofibular joint?
- Tibia
- Fibula
What are the features of the distal femur?
Anterior: -Medial epicondyle -Lateral epicondyle -Patellar surface Posterior: -Lateral condyle -Medial condyle -Intercondylar fossa/notch
Describe the Patella
- Small rounded bone
- Medial and lateral (larger) facets posteriorly (surface)
- Apex (pointed, at most inferior part)
- Example of a sesamoid bone (bone formed within tendon)
What are the features of the proximal Tibia?
Anterior: -Lateral condyle -Medial condyle -Tibial tuberosity Posterior: -Tubercles of intercondylar eminence (raised surface)= attachment points for some important knee stabilisers (cruciate ligaments) -Tibial plateau -Articular facet for fibula (flattened area)
Describe the proximal Fibula
- Facet for articulation with inferior surface of lateral condyle of tibia (diagonal)
- Head
- Neck
What is the knee joint?
- Synovial modified hinge joint
- Mainly flexion/ extension
- Also slight rotation for ‘locking’ (passive, shape of condyles)
What are the features of the knee joint?
- Synovial capsule= around whole joint
- Suprapatellar bursa= fluid filled space, have many but this is biggest
- Quadriceps tendon
- Patellar liagment
- Infrapatellar fat pad
- Articulating surfaces
What are Extracapsular ligaments?
Joint capsule reinforced by extracapsular ligaments
-Medial (tibial) collateral ligament (large and flat, closely adhered to medial meniscus)
=Flat
=Part of joint capsule
-Lateral (fibular) collateral ligament (thin and cord like)
=Cord-like
=Separate to capsule
-Tighten in knee extension, loosen in flexion
What are intracapsular ligaments?
-Anterior cruciate ligament =Prevents anterior tibial translation -Posterior cruciate ligament =Prevents posterior tibial translation Both form criss-cross shape
What are the ligaments of the knee joint?
- Anterior cruciate ligament
- Posterior cruciate ligament
- Lateral (fibular) collateral ligament
- Medial (tibial) collateral ligament
What are the fibrocartilaginous menisci?
Widen and deepen tibial articular surfaces (stability), distribute load via increased congruence between surfaces, assist In lubrication, absorb shock by cushioning the underlying bone
-Medial meniscus= rounded, sits on top of tibial plateau, larger and flatter, C shape, closely adhered for medial collateral ligament
-Lateral meniscus= more circular, smaller
Improved articulation and shock absorbing
What are the muscle compartments acting on the knee joint?
-Anterior compartment of thigh =Mainly extension -Posterior Compartment of thigh and leg =Flexion & ‘unlocking’
What are the muscles in the anterior compartment of the thigh?
-Quadriceps femoris (extension) =Vastus medialis =Vastus intermedius =Vastus lateralis =Rectus femoris -Sartoris= causes flexion of knee (Femoral nerve)
What are the muscles in the posterior compartment of the thigh?
Hamstrings: flexion -Biceps femoris -Semimembranosus -Semitendinosus (Sciatic nerve)
What are the muscles in the posterior compartment of the leg?
-Flexion-
=Gastrocnemius= large ‘calf’ muscle, 2 muscle bellies, Achilles’ tendon/ calcaneal tendon
(Tibial nerve)
-Unlocking (lateral rotation of femur on tibia)-
=Popliteus- posterior, lateral rotation (medial passive locking)
What is another name for the ankle joint?
Talocrural joint
Bracket-like/ mortise joint
(plus subtalar and transverse tarsal joints)
What are the bones of the ankle joint?
- Tibia (medial malleolus)
- Fibula (lateral malleolus)
- Talus
What are the bones of the foot?
Proximal Tarsals -Talus(anterior wider than posterior) -Calcaneus= heel Intermediate Tarsals -Navicular Distal Tarsals -Cuboid -Cuneiforms (medial, intermediate, lateral) -Metatarsals -Phalanges (distal, middle, proximal) except great toe
What are the ligaments of the ankle joint?
Joint is stabilised by medial and lateral ligaments
- Lateral ligament
- Medial ligament (Deltoid ligament)= stronger so less likely to be damaged, lateral malleolus restricts excessive eversion movements
What are the parts of the medial ligament?
- Tibionavicular ligament
- Anterior tibiotalar ligament
- Posterior tibiotalar ligament
- Tibiocalcaneal ligament
What are the parts of the lateral ligament?
- Posterior talofibular ligament
- Anterior talofibular ligament
- Calcaneofibular ligament
Describe the movements at the ankle joint
True hinge joint:
-Dorsiflexion= tibialis anterior
-Plantarflexion=
gastrocnemius (posterior compartment of leg), plantaris, soleus
Movements of eversion and inversion do not take place at ankle joint, occur between tarsal bones in foot
Describe the stability at the ankle joint
Shape of the bones at the ankle joint mean that it is far more stable in dorsiflexion than in plantarflexion (wide part of talus wedges between tibia and fibular in dorsiflexion)
Describe the innervation of the lower limb
Lumbosacral plexus
(T12-S3/4) (or Lumbar plexus T12-L4 AND Sacral plexus L4-S3/4)
-3 major nerves originating from the lumbosacral plexus
=Femoral
=Sciatic
=Obturator
-Sciatic nerve branches in popliteal fossa into
=Tibial nerve
=Common fibular (peroneal) nerve
What nerves innervate the thigh?
Anterior thigh= femoral
Posterior thigh= sciatic
Medial thigh= obturator
What nerves innervate the leg?
Anterior leg= common peroneal/ fibular
Posterior leg= tibial
Lateral leg= common peroneal/ fibular
Describe the blood supply to the thigh
-Common Iliac Artery->
-External Iliac artery->
-Femoral artery (cross underneath inguinal ligament)
=Femoral artery passes through the adductor hiatus (in adductor magnus muscle) -> popliteal artery through popliteal fossa
Describe the blood supply to the leg
- popliteal artery -> anterior and posterior tibial arteries
- anterior tibial artery -> dorsalis pedis
- Posterior tibial artery -> fibular artery and Circumflex fibular artery
What is the Femoral Triangle?
- Superior border= inguinal ligament
- Medial border= medial border of adductor longus
- Lateral border= medial border of sartorius muscle
- Important structures run through: femoral nerve, femoral artery (medially), femoral vein, lymphatic vessels within femoral canal
In what position is the jip most unstable, and why?
Flexed and medially rotated, as most of the femoral head comes out of the acetabulum
What is the purpose of ligamentum teres?
- Presence of nerve fibres believed to engage reflex action which restricts exaggerated movements and reduces risk of dislocation
- Correlation between damage or loss of ligamentum teres and increased hip dislocations
Describe how the knee ‘locks’
- During terminal knee extension with the foot free of the ground (open chain movement) the tibia rotates externally/ laterally and locks into extension
- When the foot planted, femur internally/ medially rotates to lock knee into extension
- Screw home mechanism brought about by shape of bony articular surfaces
- Popliteus muscles helps unlock knee by reversing the rotation at beginning of flexion
