2. Foot Overview Flashcards
type of joint at ankle?
compound joint - w/ 3 or more articulation surfaces
(incl. fibula, tibia, and talus)
why is the ankle/ talocrural joint also referred to as mortise?
bc it is roughtly 4-sided
fxn of ankle/talocrural joint?
bridge b/w lower leg and foot
3 segments of foot; & contents of each
- forefoot: phalanges and metatarsals
- midfoot: tarsals (except talus/calcaneus)
- rearfoot: talus and calcaneus bones
name the 3 arches of the foot
- medial longitudinal arch
- lateral longitudinal arch
- transverse arch
medial longitudinal arch:
contents; summit
- 1st metatarsal to the calcaneus
- summit: navicular
(aka Arch of the foot)
lateral longitudinal arch:
contents; summit
- calcaneus on lateral side –> 5th metatarsal
- summit: cuboid
transverse arch
contents, summit
- 1st to 5th metatarsal
- summit: intermediate cuneiform
what is synonymous with the following surfaces?
- superior
- inferior
- posterior
- anterior
- superior –> dorsal
- inferior –> plantar
- posterior –> proximal
- anterior –> distal
clinical significance of talus
no muscles attach to talus
what’s special about the navicular?
can articulate w/ all of the tarsals (but doesn’t always); could articulate w/ calcaneus
what tendon goes through the peroneal notch on the cuboid?
- Peroneal notch conveys the fibularis longus tendon;
- Which we’ve seen in the lateral surface of the calcaneus (runs under the peroneal trochlea)
other names for calcaneal process
(on cuboid)
beak of cuboid;
coronoid process
which 2 metatarsals articulat w/ anterior surface of cuboid?
4th and 5th MT
what is special about the medial cuneiform?
- more narrow on dorsum (superior), and wider on plantar aspect (the other cuneiforms are opposite)
- looks like a kidney on apex/crest
what is the shape of the LATERAL facet of the medial cuneiform?
- LATERAL looks like “L” shaped facet –> articulates w/ intermediate cuneiform
what’s the shape and articulation of the posterior/proximal facet of the medial cuneiform?
POSTERIOR looks like tear drop –> articulates w/ navicular
what’s special about the intermediate cuneiform?
it’s the smallest of the cuneiforms
shape and articulation of facet on medial surface of intermediate cuneiform?
L-shaped facet on medial surface –> articulates with medial cuneiform
what do the flat and curved surfaces of the intermediate cuneiform articulate with?
- flat –> articulates w/ second metatarsal
- curved –> for navicular
what’s special about the lateral cuneiform?
it articulates w/ the most metatarsals (2nd, 3rd, and 4th)
the dorsum is wider, and narrow and forms a crest
which facets are found on the lateral surface of the lateral cuneiform?
circular facet for the cuboid
and facets for the 4th MT and 3rd MT
3 key segments of a typical metatarsal?
- head - rounded articular surface; for proximal phalanx
- shaft
- base - square or triangular; widened area =base; bears articular facets for other MTs and some tarsals
which MT is commonly longest?
MT 2
which MT is usually shortest and largest?
MT 1
which 2 MTs are similar in length?
3rd and 4th, though latter is usually shorter
what is unique about MT 5?
has tuberosity at base on lateral side (styloid process)
very elongated and pyramidal
why is MT 1 the longest?
the first ray (MT) is used for toe-off, and sometimes bears twice as much weight during locomation as any of the other MTs
3 classes of phalanges?
- distal
- intermediate/middle
- proximal
as you proceed from 1st set of phalanges –> 5th set, what do you observe?
size decrease laterally
other names for head of phalanx;
why?
- for proximal and middle phalanges –> called TROCHLEA
- for distal phalanges –> called TUBEROSITY (bc it’s terminal)
what does the base of a phalanx articulate with?
can attach w/ metatarsal if it’s the proximal phalanx
(if not, it articulates w/ other phalanges)
which toe only has 2 phalanges?
1st toe
(proximal and distal phalanges)
