RA9 Lower Limb Anatomy Flashcards
Components of the pelvic girdle
Sacrum and hip bones
3 primary bones of the hip bone
- Ilium (superior)
- Ischium (inferior/posterior)
- Pubis (anterior/medial)
Articulation site of the left and right hip bone
Pubic symphysis
Opening formed by the ischium and pubis
Obturator foramen
Separates the 3 primary hip bones before fusion at 15-17 years
Triradiate cartilage
A large socket on the lateral face of the hip bone that articulates with the head of the femur to form the hip joint
Acetabulum
Ligaments of hip joint (3)
- Iliofemoral ligament: between ilium and femur
- Pubofemoral ligament: between pubis and femur
- Ischiofemoral ligament: between ischium and femur
Main parts of the femur (anterior)
- Head
- Neck
- Greater and lesser trochanters: joined by intertrochanteric line (anterior) and intertrochanteric crest (posterior)
- Lateral and medial epicondyles
- Lateral and medial femoral condyles
Main parts of the femur (posterior)
- Head
- Neck
- Greater and lesser trochanters: joined by intertrochanteric line (anterior) and intertrochanteric crest (posterior)
- Lateral and medial epicondyles
- Lateral and medial femoral condyles
- Linea aspera
Knee cap
Patella
Ligaments (4) and meniscus (2) of knee
- Anterior cruciate ligament (ACL)
- Posterior cruciate ligament (PCL)
- Lateral collateral ligament (LCL)
- Medial collateral ligament (MCL)
- Lateral meniscus
- Medial meniscus
- Anterior cruciate ligament (ACL): taut in (…)
- Posterior cruciate ligament (PCL): taut in (…)
extension/flexion
- Anterior cruciate ligament (ACL): taut in extension
- Posterior cruciate ligament (PCL): taut in flexion
Unhappy triad
- Anterior cruciate ligament (ACL)
- Posterior cruciate ligament (PCL)
- Medial meniscus
Where are the flexors and extensors in the lower limb?
- Flexor = posterior side
- Extensor = anterior side
Compartments of thigh muscles
- Anterior: quadriceps
- Medial: adductors
- Posterior: hamstrings
Which nerves comprise the lumbosacral plexus, lumbar plexus, and sacral plexus?
Lumbosacral plexus: L1 - S4
Lumbar plexus: L1 - L4
Sacral plexus: L5 - S4
Lumbar plexus
- What does it innervate?
- Important nerves (3)
- Innervates anterior and medial thigh
- Nerves to iliopsoas
- Femoral nerve
- Obturator nerve
Sacral plexus
- What does it innervate?
- Important nerves (7)
- Innervates gluteal region, posterior thigh, legs, foot
Important nerves:
- Superior and inferior gluteal nerves
- Nerve to piriformis
- Sciatic nerve - common fibular and tibial nerve
- Nerve to quadratus femoris
- Nerve to obturator internus
Branching of sciatic nerve
Sciatic nerve -> splits posterior to knee -> tibial nerve + common fibular nerve
Tibial nerve -> continues running posteriorly
Common fibular nerve -> runs laterally around head of fibula
Branching of common fibular nerve
Common fibular nerve -> runs laterally around head of fibula -> superficial fibular nerve (lateral leg) + deep fibular nerve (anterior leg)
Innervates the iliopsoas
Nerve to iliopsoas
Innervates the anterior thigh (quadriceps)
Femoral nerve
Innervates the medial thigh (adductors)
Obturator nerve
Innervates the gluteal muscles
Superior and inferior gluteal nerves
Innervates the lateral rotators of the hip
- Nerve to piriformis
- Nerve to obturator internus
- Nerve to quadratus femoris
Innervates the posterior thigh (hamstrings)
Tibial nerve (from sciatic nerve)
The 2 muscles that make up the iliopsoas
- Psoas major
- Iliacus
Iliopsoas
- Insertion
- Action
- Innervation
- Insertion: lesser trochanter
- Action: hip flexion
- Innervation: nerve to iliopsoas
Anterior thigh muscles (5)
(quadriceps)
- Sartorius
- Rectus femoris
- Vastus lateralis
- Vastus medialis
- Vastus intermedius
Insertion of anterior thigh muscles
- Sartorius: proximal tibia
- Rectus femoris: tibial tuberosity
- Vastus lateralis: tibial tuberosity
- Vastus medialis: tibial tuberosity
- Vastus intermedius: tibial tuberosity
Action of anterior thigh muscles
- Sartorius: hip and knee flexion
- Rectus femoris: knee extension
- Vastus lateralis: knee extension
- Vastus medialis: knee extension
- Vastus intermedius: knee extension
Innervation of anterior thigh muscles
Femoral nerve
Medial thigh muscles (5)
(adductors)
- Adductor longus
- Adductor brevis
- Adductor magnus
- Pectineus
- Gracilis
Adductor hiatus: space through which femoral artery passes through
Space through which the femoral artery passes through
Adductor hiatus
Insertion of medial thigh muscles
- Adductor longus: linea aspera of femur
- Adductor brevis: linea aspera, lesser trochanter
- Adductor magnus: linea aspera
- Pectineus: linea aspera
- Gracilis: proximal tibia
Action of medial thigh muscles
Thigh adduction
Innervation of medial thigh muscles
Obturator nerve
Gluteal muscles (3)
- Gluteus maximus
- Gluteus medius
- Gluteus minimus
Insertion of gluteal muscles
- Gluteus maximus: IT tract and femur
- Gluteus medius: greater trochanter
- Gluteus minimus: greater trochanter
Action of gluteal muscles
- Gluteus maximus: thigh extension
- Gluteus medius: thigh abduction
- Gluteus minimus: thigh abduction
Innervation of gluteal muscles
- Gluteus maximus: inferior gluteal
- Gluteus medius: superior gluteal
- Gluteus minimus: superior gluteal
Lateral rotator muscles of hip (5)
- Piriformis
- Superior gemellus
- Obturator internus
- Inferior gemellus
- Quadratus femoris
Insertion of lateral rotator muscles of hip
- Piriformis: greater trochanter
- Superior gemellus: greater trochanter
- Obturator internus: greater trochanter
- Inferior gemellus: greater trochanter
- Quadratus femoris: intertrochanteric crest
Action of lateral rotator muscles of hip
Lateral rotation
Innervation of lateral rotator muscles of hip
- Piriformis: nerve to piriformis
- Superior gemellus: nerve to obturator internus
- Obturator internus: nerve to obturator internus
- Inferior gemellus: nerve to quadratus femoris
- Quadratus femoris: nerve to quadratus femoris
Where does the sciatic nerve emerge?
The sciatic nerve emerges inferior to the piriformis
Posterior thigh muscles (3)
(hamstrings)
- Biceps femoris
- Semitendinosus
- Semimembranosus
Insertion of posterior thigh muscles
- Biceps femoris: proximal fibula
- Semitendinosus: proximal tibia
- Semimebranosus: proximal tibia
Action of posterior thigh muscles
- Biceps femoris: knee flexion, hip extension (long head)
- Semitendinosus: knee flexion, hip extension
- Semimbranosus: knee flexion, hip extension
Innervation of posterior thigh muscles
Tibial nerve
Anterior, medial, and posterior thigh compartments
- Action
- Innervation
Anterior thigh (quadriceps)
- Knee extension
- Femoral nerve
Medial thigh:
- Adduction
- Obturator nerve
Posterior thigh (hamstrings):
- Knee flexion, hip extension
- Tibial nerve
Arteries of gluteal region
Common iliac artery -> internal iliac artery -> superior and inferior gluteal artery
Arteries of the lower limb
Common iliac artery (anterior) -> external iliac artery -> femoral artery -> goes posterior through adductor hiatus -> popliteal artery
Popliteal artery (posterior) -> goes anterior through interosseus membrane -> anterior tibial artery -> dorsalis pedis artery
Popliteal artery (posterior) -> posterior tibial artery (medial) -> lateral + medial plantar artery
Popliteal artery (posterior) -> fibular artery
Femoral triangle
- Borders?
- Contains?
Borders:
- Inguinal ligament
- Sartorius
- Adductor longus
Contains:
- Femoral nerve
- Femoral artery
- Femoral vein
Superficial veins of lower limb
- Great saphenous vein: anterior to medial malleolus, empties into femoral vein
- Small saphenous vein: posterior to lateral malleolus, empties into politeal fossa
2 bones of the leg
- Tibia (medial)
- Fibula (lateral)
The tibia and fibula are connected by the (…)
The tibia and fibula are connected by the interosseous membrane
Main parts of the tibia
- Medial tibial condyle
- Lateral tibial condyle
- Tibial tuberosity
- Medial malleolus
Main parts of the fibula
- Head
- Neck
- Lateral malleolus
3 main parts of the foot
- Tarsals (7)
- Talus (ankle bone)
- Calcaneus (heel bone)
- Cuboid
- Navicular
- Medial cuneiform
- Intermediate cuneiform
- Lateral cuneiform - Metatarsals (5)
- Phalanges (3 for each toe, except big toe only has 2)
Tarsal bones (7)
Tiger Cubs Need MILC
- Talus (ankle bone)
- Calcaneus (heel bone)
- Navicular
- Medial cuneiforms
- Intermediate cuneiform
- Lateral cuneiform
- Cuboid
Joints of foot
- Tarsometatarsal joints (TMT)
- Metatarsophalangeal joints (MTP)
- Interphalangeal joints (IP)
- Tibiotalar joint (ankle joint)
- Subtalar/talocalcaneal joint
Movement at ankle (tibiotalar) joint
- Dorsiflexion: lift foot and toes up
- Plantarflexion: point foot and toes down
Movement at subtalar joint
- Eversion: bring sole lateral
- Inversion: bring sole medial
Which digit is the axis around which abduction and adduction of the toes occur?
2nd digit
Compartments of leg muscles
- Anterior
- Lateral
- Posterior
Anterior leg muscles (4)
- Tibialis anterior
- Extensor digitorum longus
- Extensor hallucis longus
- Fibularis tertius
Insertion of anterior leg muscles
- Tibialis anterior: medial cuneiform, metatarsal 1
- Extensor digitorum longus: middle and distal phalanges 2-5
- Extensor hallucis longus: dital phalanx 1
- Fibularis tertius: base of metatarsal 5
Action of anterior leg muscles
- Tibialis anterior: ankle dorsiflexion, inversion
- Extensor digitorum longus: toe (2-5) extension
- Extensor hallucis longus: hallux extension
- Fibularis tertius: eversion
Innervation of anterior leg muscles
Deep fibular nerve
Dorsal foot muscles (2)
- Extensor hallucis brevis
- Extensor digitorum brevis
Insertion of dorsal foot muscles
- Extensor hallucis brevis: proximal phalanx 1
- Extensor digitorum brevis: middle phalanx 2-5
Action of dorsal foot muscles
- Extensor hallucis brevis: hallux extension
- Extensor digitorum brevis: toe extension
Innervation of dorsal foot muscles
Deep fibular nerve
Lateral leg muscles (2)
- Fibularis longus (superficial)
- Fibularis brevis (deep)
Insertion of lateral leg muscles
- Fibularis longus: medial cuneiform, metatarsal 1
- Fibularis brevis: base of metatarsal 5
Action of lateral leg muscles
- Fibularis longus: eversion, plantarflexion
- Fibularis brevis: eversion, plantarflexion
Innervation of lateral leg muscles
Superficial fibular
Posterior leg muscles (superficial and intermediate; 4)
- Gastrocnemius (superficial)
- Soleus (intermediate)
- Plantaris (superficial)
- Popliteus (intermediate)
Insertion of posterior leg muscles (superficial and intermediate)
- Gastrocnemius: calcaneus
- Soleus: calcaneus
- Plantaris: calcaneus
- Popliteus: tibia
Action of posterior leg muscles (superficial and intermediate)
- Gastrocnemius: plantarflexion
- Soleus: plantarflexion
- Plantaris: plantarflexion
- Popliteus: internally rotate tibia on femur
Innervation of posterior leg muscles (superficial and intermediate)
Tibial nerve
What is another name for the Achilles tendon?
Calcaneal tendon
What muscles come together to form the calcanal (Achilles) tendon?
- Two heads of gastrocnemius
- Soleus (triceps surae)
Posterior leg muscles (deep; 3)
- Tibialis posterior
- Flexor digitorum longus
- Flexor hallucis longus
Insertion of posterior leg muscles (deep)
- Tibialis posterior: medial cuneiform, navicular
- Flexor digitorum longus: distal phalanges 2-5
- Flexor digitorum brevis: distal phalanx 1
Action of posterior leg muscles (deep)
- Tibialis posterior: plantarflexion, inversion
- Flexor digitorum longus: toe flexion
- Flexor hallucis longus: hallux flexion
Innervation of posterior leg muscles (deep)
Tibial nerve
Contents of medial ankle
Tom Dick And Very Nervous Harry:
- Tibialis posterior
- Flexor digitorum longus
- Posterior tibial artery
- Posterior tibial vein
- Tibial nerve
- Flexor hallucis longus
Anterior, lateral, and posterior leg compartments
- Action
- Innvervation
Anterior leg:
- Dorsiflexion, toe extension, inversion
- Deep fibular nerve
Lateral leg:
- Eversion
- Superficial fibular nerve
Posterior leg:
- Plantarflexion, inversion
- Tibial nerve
Branching of tibial nerve
Tibial nerve (posterior) -> lateral plantar nerve + medial plantar nerve -> innervates intrinsic plantar foot muscles
Intrinsic foot muscles layer 1 (3)
- Flexor digitorum brevis
- Abductor hallucis
- Abductor digiti minimi
Origin of intrinsic foot muscles layer 1
Calcaneus
Insertion of intrinsic foot muscles layer 1
- Flexor digitorum brevis: middle phalanges 2-5
- Abductor hallucis: proximal phalanx 1
- Abductor digiti minimi: proximal phalanx 5
Action of intrinsic foot muscles layer 1
- Flexor digitorum brevis: toe flexion
- Abductor hallucis: hallux abduction
- Abductor digiti minimi: digit 5 abduction
Innervation of intrinsic foot muscles layer 1
- Flexor digitorum brevis: medial plantar nerve
- Abductor hallus: medial plantar nerve
- Abductor digiti minimi: lateral plantar nerve
Intrinsic foot muscles layer 2 (3)
- Quadratus plantae
- Lumbrical 1
- Lumbricals 2-4
Origin and insertion of intrinsic foot muscles layer 2
- Quadratus plantae: calcaneus -> flexor digitorum longus
- Lumbrical 1: flexor digitorum longus -> extensor hood 2
- Lumbricals 2-4: flexor digitoum longus -> extensor hoods 3-5
Action of intrinsic foot muscles layer 2
- Quadratus plantae: assists flexor digitorum longus in toe flexion
- Lumbrical 1: MTP flexion, IP extension
- Lumbricals 2-4: MTP flexion, IP extension
MTP = metatarsophalangeal
IP = interphalangeal
Intrinsic foot muscles layer 3 (3)
- Flexor digiti minimi brevis
- Flexor hallucis brevis
- Adductor hallucis (transverse and oblique heads)
Insertion of intrinsic foot muscles layer 3
- Flexor digiti minimi brevis: proximal phalanx 5
- Flexor hallucis brevis: proximal phalanx 1
- Adductor hallucis: proximal phalanx 1
Action of intrinsic foot muscles layer 3
- Flexor digiti minimi brevis: MTP 5 flexion
- Flexor hallucis brevis: MTP 1 flexion
- Adductor hallucis: adduct hallux
Innervation of intrinsic foot muscles layer 3
- Flexor digiti minimi brevis: lateral plantar nerve
- Flexor hallucis brevis: medial plantar nerve
- Adductor hallucis: lateral plantar nerve
Intrinsic foot muscles layer 4 (2)
- Plantar interossei
- Dorsal interossei
- Plantar interossei: proximal phalanges 3-5
- Dorsal interossei: proximal phalanges 2-4
Action of intrinsic foot muscles layer 4
- Plantar interossei: toe adduction (PAD)
- Dorsal interossei: toe abduction (DAB)
Innervation of intrinsic foot muscles layer 4
Lateral plantar nerve
Patient has an injury to the left hip joint and exhibits weakness of the gluteus medius resulting in the Trendelenburg gait. When asked to stand on one leg, what is the most likely finding?
A. When standing on the left leg, the pelvis will tilt to the left because of weak hip abduction.
B. When standing on the left leg, the pelvis will tilt to the right because of weak hip abduction.
C. When standing on the right leg, the pelvis will remain level because there is no weakness.
D. When standing on the right leg, the pelvis will tilt to the left because of weak hip abduction.
B. When standing on the left leg, the pelvis will tilt to the right because of weak hip abduction.
A man is unable to dorsiflex his ankle - clinical case of foot drop. Upon examination, you see something that tells you the cause. What did you see?
A. A stab wound scar over his femoral triangle.
B. A stab wound scar over his vastus medialis muscle.
C. A laceration scar over his proximal fibula.
D. A 10 degree valgus deformity of his tibia shaft due to a malunited fracture.
C. A laceration scar over his proximal fibula.
An injury to the proximal fibula will lead to an injury of the deep fibular nerve, which innervates the anterior part of the leg. Thus, leads to foot drop.
Which of the following muscles are flexors of the thigh?
A. Psoas
B. Pectineus
C. Rectus femoris
D. Vastus lateralis
A, B, and C
A: Psoas: part of iliopsoas
B: Pectineus: originates on pubis, so can flex hip/thigh
C: Rectus femoris: originates on ilium, so can flex hip/thigh
Boundaries of popliteal fossa
- Biceps femoris and semimembranous superiorly
- Gastrocnemius inferiorly
Which muscle passes through the greater sciatic foramen?
Piriformis
(piriformis peers through the hole)
What does the femoral triangle contain?
Femoral nerve, artery, vein, and lymphatic vessels
“Unlocking” of the knee joint to permit flexion is caused by the action of which muscle?
Popliteus
- Contraction causes lateral rotation of the femur on the tibia, unlocking the knee
The anterior cruciate ligamnet resists (…) of the tibia
The anterior cruciate ligament resists anterior translation of the tibia