Foot and Ankle Flashcards
Gastrocnemius
O: Medial Head- prox. post medial femoral condyle, capsule of knee
Lateral Head- condyle of femur, knee capsule
I: posterior calcaneus via Achilles tendon
A: plantarflexion, knee flexion
N: Tibial N.
Soleus
O: Posterior tibia and fibula
I: posterior calcaeus via achilles tendon
A: plantarflexion
N: Tibial N.
Tibalis Posterior
O: Posterior surface of tibia, fibula, and interosseous membrane
I: inferior surface of navicular, cuneiforms and metatarsals
A: plantarflexion, inversion, eccentrically slows pronation
N: Tibial N.
Tibialis Anterior
O: Upper 2/3 of lateral tibial surface
I: medial cuneiform and base of 1st metatarsal
A: dorsiflexion, inversion, pulls arch upward
N: Tibial N.
Peroneus/Fibularis Longus
O: head and upper 2/3 of fibula
I: plantar surface of medial cuneiform and 1st metatarsal
A: eversion, plantarflexion, pulls arch into pronation in closed chain exercises
N: Tibial N.
Peroneus/Fibularis Brevis
O: mid-lower 2/3 of fibula
I: 5th metatarsal tuberosity
A: eversion, plantarflexion
N: Tibial N.
Peroneus/Fibularis Tertius
O: Distal 1.3 of anterior fibula I
: base of 5th metatarsal
A: eversion, dorsiflexion
N: Tibial N.
Tibia
bears 90% of weight, is rotated laterally around a vertical axis from proximal to distal
Fibula
bear remaining 10% of weight
lateral malleolus projects further distally than the medial (tibial) malleolus, also site more posteriorly
Tarsals
Foot divided into 3 sections: rear, mi and fore-foot
the tarsals are found in the mid and forefoot
there are 3 arches: medial and lateral longitudinal and transverse (the form a triangle on the bottom of the foot)
Talus
Has no muscular attachments
more than half is covered with articular cartilage
most superior domed aspect is called the head, and is easist to palpate in the sinus tarsi region just distal to the tibial/fibular articulations
inferiorly, it articulates with 3 facets of calcaneus
anteriorly, articulates with the navicular
medial and lateral aspects articulate with their respective malleoli
Calcaneus
largest and strongest tarsal bone: first bone to recieve ‘ground reaction’ forces
transmits body weight from talus to the ground
is protected by thick fat pad
posterior aspect attaches to Achilles tendon
anterior aspect articulates with cuboid
Navicular
“boat” shaped
found between head of talus and the cuneiforms
the navicular tuberosity protrudes for easy papation
Cuneiforms
3 wedge-shaped bones: medial, intermediate and lateral
form the transverse arch of the foot
articulate with 1st, 2nd, and 3rd metatarsals
Cuboid
is 6-sided (just like a real cube)
posteriorly articulates with calcaneus
medially articulates with lateral cuneiform
anteriorly articulates with 4th and 5th metatarsals
Metatarsals
5 is most posterior and its tuberosity = attachment for peroneus brevis
metatarsals + phalanges = forefoot
numbered 1-5: #1 is thickest and shortest, #2 is thinnest, longest, and most securely anchored
allows you to bear more weight through 2nd toe and gives great toe more range of motion
shafts of metatarsals are concave on the plantar side: facilitates load absorption
There are 2 sesamoid bones just posterior to 1st metatarsal on plantar surface, and the Flexor Hallucis Longus runs through the tunnel they create (making the big toe more effective during push-off): they also increase the moment arm of the Flexor Hallucis Brevis.
Phalanges
there are 14 total: 1st toe has 2, 2nd-5th each have 3
the (proximal) bases are concave, the shafts are small, and the (distal) heads are convex
Dorsiflexion/Plantarflexion
Flexion/Extension
Inversion/Eversion
Ab/Adduction
Pronation/Supination
Dorsiflexion/Plantarflexion- saggital plane
Flexion/Extension- saggital plane
Inversion/Eversion- frontal plane
Ab/Adduction- transverse plane
Pronation/supination- occurs in 3 planes about an oblique axis with 1˚ of freedom (usually references subtalar joint)
pronation occurs when arch is low (dorsiflexion, abduction and eversion), supination occurs when arch is high (plantarflexion, adduction, inversion)
Proxmial Tibiofibular Joint
synovial
dorsiflex/plantarflex - small amount of gliding
stabilized by biceps femoris, popliteus, LCL and tibiofibular ligaments
Distal Tibiofubular Joint
Syndesmotic
mortise widens during dorsiflexion
stabilized by interosseous membrane/ligament, anterior & posterior tibiofobular ligaments
Talocrural Joint
oblique hinge joint with 1˚ of freedome
supported medially by deltoid ligament and laterally by anterior talofibular, calcaneofibular and poterior talofibular ligaments (aka lateral collateral ligament
axis of rotation runs through malleoli
primary motions are plantarflexion and dorsiflexion
if gastroc is tight, dorsiflexion will be greater with knee flexed
endfeel is firm for both plantar and dorsiflexion
the Talus approximates with the mortise
Subtalar Joint
oblique hinge joint with 1˚ of freedom
axis of rotation runs from posterior, lateral and inferior to anterior, medial and superior (pure A-P axis)
primary motion is inversion/eversion
Posterior facet of talus (convex) is largest articulating surface with concave facet of calcaneus
passively stabilised by interosseous and cervical ligaments
motion available influences ability of midfoot and forefoot to be
Function: supination/pronation- allows the foot to be both adaptile and rigid during gait, transmits/absorbs rotational forces between foot and leg
Tranverse Tarsal Joint (aka Midtarsal or Chopart’s Joint)
Talonavicular portion: rounded anterior talus head fits into concave navicular (ball-and-socket-like), supported by “spring ligament”, provides the most mid-tarsal motion
Calcaneocuboid portion: very stable due to interlocking of these two bones, very little motion, support comes from long and short plantar ligaments, moves through logittudinal and oblique axes: most mobile when foot is pronated
these two joints are most mobile when axes of motion are parallel (subtalar joint is pronated)
joint “locks” in supination, axes are crossed
Tarsometatarsal joint (aka Lisfranc’s joint)
forms the tranvserse metatarsal arch
the cuboid and cuneiforms articulate with the bases of the 5 metatarsals
injuries can be very painful due to amount of stress placed here during WB activity
1st metatarsal-medial cuneiform = largest joint with independent joint capsule (the rest share a second)
4th and 5th-cuboid = most mobile joint 2nd-middle cuneiform = least mobile this joint allows the foot/ankle to change shape and adapt to terrain
one ‘ray’ = one cuneiform, it’s articulating metatarsal and respective phalanges
2nd ray = central reference point, 1st ray assists in bringing medial border of foot off the ground during push-off
Intermetatarsal Joint
synovial joints between 2nd-3rd and 3rd-4th metatarsal bases
stabilized by tranvserse metatarsal ligament
small amount of plantar and dorsal glide during movement
Metatarsaophalangeal
convex metatarsal head articulates with concave phalangeal base
these joints are bi-axial: flexion/extension, ab/adduction
extension at MTP joint is critical for normal amb.
Interphalangeal joint
hinge joints with 1˚ of freedom (important for balance)
closed packed position = full extension
Function: Arch of the Foot
Allows foot to adapt to various surfaces
absorbs forces
provides weight-bearing surface
assists and supports foot during supination/pronation
Loading: weight is distributed 50/50 between calcaneus and metatarsal heads (heel and toe experience greatest forces)
Deformities of the Foot
Pes Planus (flat-foot): can be congenital or aquired, rigid or flexible, increases pronation, medial rotation (proximally), and the stress on the muscles that control pronation
**Pes Cavus (excessive high arch): **rigid foot makes for poor shock absorption, those forces that are not absorbed are transmitted proximally, associated with lateral LE rotation (varus knee)
Hallux Valgus (bunion): lateral deviation of Great Toe- results in bursae inflammation, involves the entire ray, makes wearing shoes very painful, can only prevent the condition from worsening (fix requires surgery)
