Lecture 8: The Lower Limb Flashcards
Each side of the pelvis is made up of 3 bones that are fused together, which reflects what latin name?
Os Coxae
Of the bones of the lower limb that are paired, which is considered weight bearing and which is more associated with attachment for muscle?
Weight bearing = tibia
Muscle attachment = fibula
What type of bone is the patella?
Sesamoid bone = a bone embedded in a tendon
The patella is what allows for complete ____________ of the lower limb. It also has a tendency to slide ____________
Extension
Laterally
Thickened parts of the fibrous articular capsule associated with the hip joint are called ______________ ligaments
Intrinsic
What are the 3 hip joint intrinsic ligaments?
Iliofemoral ligament
Pubofemoral ligament
Ischiofemoral ligament
Name the 3 gluteal muscles
Gluteus maximus
Gluteus medius
Gluteus minimus
What muscle is enclosed by fascia, is found at the lateral thigh, and functions to abduct, medically rotate, and flex the thigh?
Tensor fascia lata
What is the IT band?
Distinct feature of the fascia lata = iliotibial tract
Where is the pririformis located?
Deep to the gluteus maximus and medial to gluteus medius
What muscle leaves the pelvis through the lesser sciatic foramen and what muscle does it pair with?
Obturator internus
Obturator externus
Where is the quadratus femoris muscle located?
Deep gluteal region, inferior to gluteus medius and minimus
Describe the evolution of the Os Coxae (pelvis)
Pelvis becomes more stable and bones become reshaped and rearranged to allow for greater stability and differences in weight bearing
In comparing the shift from chimp to human pelvis: the ilium is reoriented, the shape of the pelvic inlet/outlet have changed, and the size of the ___________ increases because we bear all weight on hind limbs
Acetabulum
In comparing pelvis and standing posture in gorillas and humans, gorillas have longer _________ and ______ which provide a mechanical advantage for climbing.
Ischium
Ilium
Describe the differences in the intrinsic capsular ligaments of the human hip as compared to chimps
The capsular hip ligaments become taught at a higher degree of extension in humans than in quadrupedal primates
The primate gluteus maximus extends much further down the femur in chimps than in humans. What function does the gluteus maximus serve in other primates that it does not do much of in humans?
Abductor
The muscle that contributes the most in our gluteal region is the _______________, while in chimps and gorillas it is the ______________
Gluteus maximus
Gluteus medius
In contrast to the cruciate/intracapsular ligaments, there are 5 extrapsular (external) knee joint ligaments that consist of:
Patellar ligament Fibular collateral ligament Tibial collateral ligament (intrinsic) Oblique popliteal ligament (intrinsic) Arcuate popliteal ligament
[Intrinsic = thickened capsule]
What are cruciate ligaments/where are they located?
Intraarticular knee joint ligaments - found in the knee
Anterior cruciate ligament
Posterior cruciate ligament
What is the longest muscle and where is it found?
Sartorius, thigh
What muscles of the thigh make up the quadriceps femoris?
Vastus lateralis
Rectus femoris
Vastus medialis
Vastus intermedius
What muscles make up the superficial medial thigh (adductors)?
Pectineus
Adductor longus
Adductor brevis
Gracilis
What muscles make up the deep medial thigh?
Obturator externus
Adductor magnus
What are the posterior thigh muscles?
Biceps femoris
Semitendinosus
Semimembranosus
Gracilis
When people say “hamstrings” what muscle are they referring to?
Adductor magnus
Compare the carry angle of the femur in gorillas vs. humans
Gorillas: straight, feet are placed further from midline
Humans: angled, places feet closer to midline for bipedal gait
The repositioning of human thigh muscles through evolution were needed to counteract the increased carry angle of the femur. What muscle adaptation counters the lateral glide of the patella due to this increased carry angle?
Distal extension of the vastus medialis
What aspect of patellar bone structure related to increased carry angle of the femur is found in humans and australopithecines but not in chimpanzees?
Patellar notch
What is considered to be the true ankle joint?
Talocrural joint
What joint in the foot is located most proximal to the ankle?
Transverse tarsal joint
What joint is found where the talus rests on the calcaneus of the foot? What supports the fibrous capsule?
Subtalar (talocalcanean) joint
Interosseus talocalcaneal ligament
These four parts make up what ligament:
Anterior tibiotalar part
Tibionavicular part
Tibiocalcaneal part
Posterior tibiotalar part
Deltoid ligament in the ankle (aka medial)
The plantar calcaneonavicular ligament and medial (deltoid) ligaments are found where?
Ankle/foot
The lateral ligaments of the foot and ankle consist of what 3 discrete ligaments attaching lateral malleolus to talus and calcaneus?
Anterior talofibular ligament
Posterior tibiofibular ligament
Anterior tibiofibular ligament
What is the name of the long, thick muscle on the anterolateral surface of the tibia?
Tibialis anterior
What muscle is responsible for extending the lateral four toe digits?
Extensor digitorum longus
What muscle fuses with the digitorum longus proximal in the foot but is only variably present?
Fibularis tertius
What muscle is responsible for extending the big toe?
Extensor hallucis longus
What relatively large muscle extends the entire lateral side of the fibula?
Fibularis longus
What muscle is deep to fibularis longus?
Fibularis brevis
What are the muscles of the posterior compartment?
Gastrocnemius
Soleus
Plantaris
What are the four deep posterior muscles of the crural compartment?
Popliteus
Flexor hallucis longus
Flexor digitorum longus
Tibialis posterior
What aspect of triceps surae is indicative of a more limited range of movement in humans compared to chimps?
Shorter muscle bellies; also note that the soleus origin is more extensive in humans
What is the difference in function of the tibialis anterior and fibularis longus between chimps and humans?
Chimps: permit midtarsal break (flexibility)
Humans: enhance midtarsal stability (rigidity)
Describe the variation in extant hominid digital flexors in the great apes vs. humans
Great apes = flexor digitorum tibialis and fibularis
Humans = flexor hallucis longus
Only one muscle in humans, so we have less dexterity with our toes
What two muscles make up the dorsum of the foot?
Extensor hallucis brevis
Extensor digitorum brevis
What are the 3 plantar muscles that extend from the calcaneus to phalanges? (First layer)
Abductor digiti minimi
Flexor digitorum brevis
Abductor hallucis
What 2 plantar muscles make up the second layer?
Quadratus plantae
Lumbricals
What 3 plantar muscles are found in the third layer?
Flexor digiti minimi brevis
Adductor hallucis
Flexor hallucis brevis
What plantar muscles make up the fourth layer?
3 plantar interossei
4 dorsal interossei
Describe the variation in the flexor digitorum brevis (small flexor in the foot) between great apes and humans; what does this mean for humans?
Great apes: FDB originates on the tendon
Humans: FDB originates on the calcaneus
Humans are able to “toe-off” more powerfully
Describe the types of movement possible in the subtalar and transverse tarsal joints
Inversion/eversion between talus and calcaneus
Endorotation/exorotation at transverse tarsal joint
In human primates, the midaxis of the foot is the _____ digit which is termed ___________. In non-human primates, the midaxis is the ________ digit, which is termed ____________.
Third
Mesaxonic
Second
Entaxonic
The metatarsal phalangeal break is indicative of the ________ foot. This is indicated by hyperextension in the ______ of the foot, and rigidity in the _____ region
Human
Arch
Toe
Describe the “Windlass” effect on plantar fascia
The fascia is pulled taught when toeing off using the MP joint as a windlass/pully
Who has a bigger calcaneus, chimps or humans? Why?
Humans, because we step with our heels, not the forefoot like chimps do
In terms of flexibility vs. rigidity at the midtarsal joint, there is greater ________ with calcaneal inversion, and greater __________ with calcaneal eversion.
Rigidity
Flexibility
In terms of flexibility/rigidity: More continuous surface area in subtalar joint articular surfaces may be indicative of more ___________ while less is indicative of greater _____________.
Flexibility
Rigidity
In terms of variation in flexor digitorum brevis among extant primates, humans have 100% origination off the _____________, which means that we have _______ power with toeing off than with origination off of a tendon
Calcaneus
More
General mammalian characteristics of the lower limb include:
Expansion of the _______ attachment of pelvis
Femoral neck at sharp angle to _________
Limb joints operating in a single __________
Sacral
Shaft
Plane
General primate characteristics of the lower limb include:
Tendency for __________ posture of the trunk
______________ hallux
Upright
Opposable
General hominoid characteristics of the lower limb include:
Iliac blade flaring widely in _________ plane
Subtalar and transverse joints of foot ________
Digits elongated; _______ toe longest
Development of inferior process of heel _______
Coronal
Mobile
Second
Tubercle
General human characteristics of the lower limb include:
Sacrum wide and ________ inferiorly
SI joint closer to __________
Iliac ______ strengthens the ilium for stresses of abduction
Gluteus _________ reoriented as extensor of hip
Gluteus medius and minimus and tensor fasciae latae reoriented as __________
Medial ___________ arch present in foot
Hallux permanently __________ parallel with other digits
Narrows Acetabulum Pillar Maximus Abductors Longitudinal Adducted
