Bones and muscles of the lower limb Flashcards
Name the bones of the lower limb
The femur makes up the thigh, the tibia is medial and the fibula laterally.
Name the bones of the foot.
The calcaneus and talus bones are next to each other,
then the navicular in front of the talus and the cuboid bone in front of the calcaneus.
The 3 cuneiform bones in front of the navicular medially and then the lateral cuneiform is in front of the cuboid bone.
Next are four metatarsal bones and after them the four phalanges
What are the landmarks of the main bones of the lower limb?
Femur: head of femur, femoral neck, the greater and lesser trochanter, linea aspera on shaft, lateral and medial epicondyle and the real lateral and medial condyles (with smooth articular surfaces).
Tibia: Lateral and medial condyle, tibial tuberosity, medial malleoulus.
Fibula: head of fibula (inserts into lateral condyle of tibia) and lateral malleolus.
Name the three main parts that make up the pelvis.
The ilium, the pelvis and the ischium.
Name the major muscles of the anterior compartment of the thigh.
Superficial: Vastus lateralis, vastus medialis, rectus femoris, sartorius, tensor fascia lata.
Middle: vastus intermedius (under rectus femoris).
Name the muscles of the medial compartment of the thigh
The adductors: Medial to lateral
Superficial: Gracilis, adductor longus, adductor brevis and pectineus.
Deep: Adductor magnus (takes up entire space of the floor of medial compartment).
Name the muscles of the posterior thigh compartment
From medial to lateral:
The hamstrings family
semimembranosus, semitendinosus, long head of biceps femoris and short head of biceps femoris.
Name the muscles of the gluteal region (butt)
Superficial: Gluteus maximus
Deep: Gluteus medius, gluteus minimus, piriformis, obturator internus and quadratus femoris.
Name the accessory features of the lateral thigh compartment. (There are 2)
The iliotibial tract and its own muscle, the tensor fascia lata.
Where is the gluteus maximus and what is its action?
Gluteus maximus is superficial and originates from the posterior edge of the iliac crest, the dorsal surface of the sacrum and coccyx and it inserts onto the iliotibial tract or gluteal tuberosity (top of femur).
Gluteus maximus is a hip flexor and extensor (lifts the whole limb up) and a lateral rotator of the limb.
where is gluteus medius and gluteus minimus and what are their actions?
Gluteus medius and minimus are deep to the gluteus maximus muscle. They arise from the posterior but lateral edge of the iliac crest and insert onto the greater trochanter of the femur.
Their action is abduction of the limb (like in star jumps), opening and closing the legs.
where is the piriformis muscle and what is its action?
Piriformis is deep, and comes off the outside edge of the sacrum and inserts onto the greater trochanter. Its main action is lateral rotation of the thigh in extension.
where is the obturator internus muscle and what is its action?
It originates from the obturator membrane that covers the obturator foramen and inserts onto the greater trochanter.
Its main action is lateral rotation of the limb when extended.
where is the muscle quadratus femoris and what is its action?
Quadratus femoris arises from the lateral side of the ischial tuberosity and it inserts onto the quadrate turbercle of the femur.
Its main action is lateral rotation of the thigh.
Where is the muscle semimembranosus and what is its action?
semimembranosus is the most medial posterior thigh muscle and it originates from the ischial tuberosity and inserts onto the medial condyle of the tibia (also medial).
Its main action is medial rotation of the leg (lower leg) and extension of the thigh.
where is semitendinosus and what is its action?
Semitendinosus is next to and ontop of semimembranosus and originates from the ischial tuberosity and inserts onto the medial side of the knee, at the pes ancineus with gracilis and sartorius.
Where is the long head of biceps femoris and what is its action?
The long head of biceps femoris is the most lateral posterior thigh muscle and it originates from the ischial tuberosity and inserts onto the lateral side of the head of the fibula.
Its main action is lateral rotation and flexion of the leg.
where is the short head of the biceps femoris and what is its action?
Short head of biceps originates from the lateral side of the linea aspera (shaft of the femur) and forms one tendon with the long head to insert onto the lateral side of the head of fibula.
Where is rectus femoris and what is its main action?
Rectus femoris is a superficial anterior thigh muscle. It originates from the ASIS (anterior superior iliac spine) and merges into the patella tendon to insert onto the tibial tuberosity.
Its main action is extension of the leg.
where is vastus medialis and what is its action?
Vastus medialis is the medial most quad muscle in the superficial layer. It originates from the medial lip of the linea aspera and inserts onto the tibial tuberosity by merging into the patella tendon.
where is the vastus lateralis muscle and what is its action?
vastus lateralis is the most lateral muscle in the superficial layer.
It originates from the lateral lip of the linea aspera, greater trochanter and then inserts onto the tibial tuberosity by merging into the patella tendon.
it is an extensor of the leg.
Where is vastus intermedius and what is its action?
Vastus intermedius, as the name suggest, is an intermediate anterior thigh muscle. It is sandwiched between the quadriceps above and the adductor muscle below.
It originates from the femoral shaft and merges into the patella tendon with the three other quadriceps muscles to insert onto the tibial tuberosity.
it is an extensor of the leg.
where is adductor brevis and what is its action?
Adductor brevis originates from the inferior ramus of the pubis and inserts onto the proximal (topmost) part of the linea aspera on the femural shaft. It is the shortest adductor muscle.
Its main action is adduction of the thigh.
where is the adductor longus muscle and what is its action?
Adductor longus originates from the inferior ramus of the pubis and inserts onto the middle part of the linea aspera, on the femur.
It is an adductor of the thigh.
Name the muscles of the anterior compartment of the leg
Hint: Timothy has a dirty, nasty toe
Tibialis anterior, extensor hallicus longus, extensor digitorum longus, fibularis tertius.
SIDE NOTE: To remember what is on the dorsum of the toe, use the acronym:
‘Timothy has a nasty dirty toe’;
Timothy=T=Tibialis anterior
Has=H= extensor hallicus longus
A= anterior tibial artery
Nasty=N= nerve
Dirty=D=extensor digitorum longus
Toe=T= fibularis tertius.
Name the muscles in the lateral compartment of the leg.
Fibularis longus and brevis
Explain how the posterior muscles of the leg enter into foot.
The posterior muscles enter the foot by coming downwards, passing under and around the medial malleolus. There is a special covering that protects these tendons and keeps them within and between the medial malleoulus and medial side of the calcaneus. This is the flexor retinaculum.
You can use the acronym ‘Tom, Dick And Very Naughty Harry’.
Tom=tibialis posterior
Dick= Felxor digitorum longus
And=Artery
V=Vein
Naughty= nerve
Harry=Flexor hallicus longus.
Where is the gastrocnemius and what is its action?
The gastrocnemius is a superficial posterior leg muscle. There are lateral and medial heads that originate from the lateral and medial codyles of the femur respectively. The two heads combine to form the huge calcaneal or archilles tendon that inserts onto the calcaneal tuberosity.
The gastrocnemius does plantarflexion of the entire foot and it is a flexor of the leg.
where is plantaris and what is its action?
plantaris originates from the lateral supracondylar ridge of the femur. It then crosses back behind the knee and enters the popliteal fossa, where it hides between gastrocnemius and soleus. It then forms a single tendon which fuses into the calcaneal tendon.
Plantaris is absent in 10% of the population.
Its main action is plantarflexion of the foot.
Where is the popliteus muscle and what is its action?
it originates from the posterior surface of the tibia and inserts onto the lateral condyle of the femur.
This muscle is a deep posterior leg muscle, and lies diagonally across the back of the knee. It has a bursa between it and the posterior knee surface.
It also forms the floor of the popliteal fossa, hence the name.
Its main actions are unlocking the femur by laterally rotating it to allow flexion of the leg.
where is the muscle flexor digitorum longus and what is its action?
Flexor digitorum longus is a deep muscle that originates from the medial surface of the tibia. It has a long tendon that runs down the leg and passes behind the medial malleolus (It is D=Dick in our acronym). It splits into four tendons that inserts onto the plantar or bottom surface of the four digits.
remember: extensor tendons insert dorsally, flexor tendons insert underneath.
its main action is flexion of the toes.
where is the muscle tibialis posterior and what is its action?
Tibialis posterior originates from the posterior surface between the tibia and fibula. Its tendon travels downwards, behind the medial malleolus and inserts onto the medial tarsal bones (especially the navicular tuberosity).
Its main action is plantarflexion of the foot and inversion of the foot. However, both tibialis anterior and posterior together enable maximum inversion of the foot.
what and where are the three arches of the foot?
There are two longitudinal arches that run on the sides of the foot, called the medial and lateral longitudinal arches respectively.
Then there is transverse arch that runs perpendicular to the foot.
which muscles are in the first layer of the foot?
Abductor digiti minimi- abducts the pinky toe and abductor hallicus- abducts the big toe.
The third muscle is flexor digitorum brevis, which flexes the digits with flexro digitorum longus in the posterior compartment of the leg.
What are the contents of the femoral triangle?
The femoral triangle is in the groin.
Its medial border is adductor longus muscle, the superior border is the inguinal ligament and the lateral border is the medial border of the sartorius muscle.
Inside the triangle, from lateral to medial:
the femoral nerve, femoral artery, femoral vein and the femoral canal and inguinal lymph nodes.
The acronym to remember the contents is:
NAVEL
N-nerve, A-artery, V-vein, E-empty space (for vein expansion and L-lymph nodes
what are the contents of the popliteal fosa?
The contents are (medial to lateral):
The popliteal fossa is a diamond shaped space, with superior medial and lateral and inferior medial and lateral borders:
Superiomedial border: Semimembranosus.
Superiolateral border: Biceps femoris.
Inferiomedial border: Medial head of the gastrocnemius.
Inferiolateral border: Lateral head of the gastrocnemius and plantaris.
The contents of the fossa from medial to lateral are:
Popliteal artery,
Popliteal vein,
Tibial nerve, c
ommon fibular nerve.
