Functional Anatomy Flashcards
Normal tibial torsion
15 to 25 degrees external
Normal tibiofibular varus
6 degrees
Subtalar neutral definition
STJ neither pronated nor supinated
Distal tibiofibular joint is what type of joint?
convex concave?
normal movement?
Fibrous.
Syndesmoses supported by ant/post tibfib ligament and inferior transverse and interosseous ligaments
Convex tibia on concave fibula.
Movement: 1 to 2 mm separation with and 2.5 degree ER of fibula with DF
Talocrural joint is what type? axes? close packed/loose packed? capsular pattern? normal movement(OKC, CKC, for gait)
Synovial uniaxial, modified hinge.
Triplanar- axis is oblique to body planes.
Trochlea is 2.5 mm wider anteriorly.
Closed packed position: DF ( little or no inv/ev.
Resting position: 10 degrees PF
Capsular pattern: greater limitation of PF tan DF (although sometimes appears reversed clinically)
Normal ROM: OKC (20 deg. DF, 50 deg PF); CKC (36-43 deg. DF)
For gait: 4-10 deg. DF, 20 deg PF (<4-10 deg = clinical equinas)
Instant center varies only 1.2 cm.
Contact area 4.4cm
Distal Tibio-Fibular Joint
What happens with:
foot pronation/supination/PF/DF
Functions with proximal Tib-fib joint
With supination of foot- head of fibula glides distally and posteriorly
With pronation of foot- fibula glides proximally and anteriorly and rotates exterally
With plantar flexion- fibula glides distally with slight medial rotation
With dorsiflexion- fibula glides proximally with external rotation
Ankle Ligaments (which ones resist INV, EV, IR, ER)
In Loaded Position: 100% of inv/ev stability accounted for by joint surfaces
In Unloaded Position: 3 ligaments account for 87% of resistance to inv (ATF, PTF, CF); Deltoid lig accounts for 83% of resistance to ev.
ATF and Deltoid resist IR
CF primarily resists ER
Distal Tibio Fibular Joint ligaments and Injuries
Ligaments: anterior tibiofibular ligament posterior tibiofibular ligament transverse ligament interosseous ligament
Syndesmotic Injuries:
high ankle sprain
syndesmotic disruption in fx and dislocation
Talocrural joint ligaments:
Rank weakest to strongest.
Ankle instability implicated in what two things?
Weakest to strongest:
ATFL < PTFL < DF < Deltoid
Ankle instability implicated in:
posterior tibial tendon dysfunction and achilles tendinosis
Sub-talar joint is what type? What purpose does it serve? close packed/ open pack positions? capsular pattern? articular areas concave/convex? what provides dynamics stability? static stability?normal ROM? ROM for gait?
synovial, saddle shaped joint
Transfers transverse motion to the leg.
Closed packed position: supinated
Open packed position: midway between supination and pronation
Capsular Pattern: greater limitation in supinaton than pronation
2 articular areas:
1) posterior= convex calcaneous with concave talus
2) anterior= concave calcaneous with convex talus
Dynamic stability by PT, FHL, FDL tendons.
Static stability by anteromedial calcaneus (stabilty of hindfoot)
ROM generally 3:2 (inv:ev) total of 30-45 deg
Gait requires avg 20 deg inv, 10 deg ev
Sub Talar Joint Ligaments
Posterior talo-calcaneal ligament
Interosseous Ligament - can be damaged in ankle sprain, can contribute to excessive anterior translation of talus
Midtarsal joint is what type of joint? describe axes. describe function. movement is dependent on what?
(transverse tarsal joint aka chopart’s) Talo-navicular/calcaneo-cuboid
Ball and socket synovial joint. Triplanar
2 axes (longitudinal and oblique)
Axes parallel with STJ in pronation and= mobile adapter
axes cross with STJ in supination= locked, rigid lever
aids in raising and lowering arch and absorbs some of the horizontal plan motion
movement is dependent on position of STJ
key ligaments for arch support and plantar aspect support of mid tarsal join
Long plantar- calcaneo cuboid + 2,3,4 met
Short plantar- calcaneo cuboid
Plantar calcaneonavicular (spring ligament)
Plantar aponeurosis
Mid-Tarsal Joint ligaments
Plantar calcaneo-navicular ligament ( spring and interosseous ligs of joint capsule support TNJ)
Bifurcate (calcaneo-cuboid and calcaneo-navicular) and long plantar ligs support calcaneo-cuboid joint
Cuneonavicular joint (intertarsal joint)
synovial modified ovoid
PF, DF, INV, EV
closed packed = supination
open packed = mid way between pronation and supination
convex navicular with concave cuneiforms
cuneometatarsal
aka Lisfranc
plane synovial joints-gliding
transverse arch shaped by wedges of lateral and intermediate and reverse wedge of intermediate cuneiform
prime factor in transverse arch
disruption to ligaments leads to dislocation of medial aspect of foot –> leads to midfoot sprain
cubometetarsal
sometimes called Lisfranc
modified sellar synovial joint considered together
cuboid articulates with 4th and 5th mets distally
Cubonavicular
functions as a syndesmosis
if synovial, capsule is contguous with cuneonavicular joint capsule
dysfunction begins with pes planus deformity
intercuneiform and cuneocuboid joints
modified synovioal ovoid joints
one degree of freedom: INV/EV
dysfunction of cuneocunoid joint results from collapse of plantar supporting structures causing subluxation of cuboid
Forefoot consists of what? what is the 1st ray?
3 general regions:
1) tarso-metetarsal (lisfranc)
2) MTP
3) Interphalangeal
- 1st ray articulation: medial cuneiform and 1st metatarsal
Intermetatarsal Joints are what type of joint?
movements? purpose?
Modified ovoid joints
Movements confined to dorsal/plantar glide
Allows fanning and folding motion of foot
Metatarsophalangeal joint is what type of joint? Describe capsule. Convex concave?
1st MTP ROM with gait, running/squatting/dancing? What other bones are near 1st MTP? How much weight do those bones bear during gait cycle?
Modified ovoid joints
Capsule confined to each joint
Concave distal articulates with convex proximal bone
1st MTP DF 60 degrees during gait, but >90 degrees with running, squatting and dancing
Sesamoids connected distally to the base of the proximal phalanx by extensions of the FHB (plantar plate)
Sesamoids bear up to 3x body weight during gait cycle
Interphalangeal joints are what type of joint? how many DoF?closed/open packed positions?capsular pattern?
synovial hinge joints with 1 DoF
Closed packed: full extension
open packed: slight flexion
Capsular pattern = more limitation of flexion than extension
What are accessory Bones? give 2 examples.
Bones that failed to unite during ossification - CONGENITAL
Secondary to a fx which does not heal ACQUIRED
- accessory navicular (4-14% of population). may lead to medial ankle/foot pain
- OS TRIGONUM which is posterior between talus and calcaneus ( 10% of population)–> can lead to angle pain- impingement. usually no symptoms until you bruise it
Key ligaments for tarso-metatarsal joint
3 Ligaments
1) Dorsal
2) Plantar
3) Interosseous
- prevent joint separation
- injured in lisfranc sprain and lisfranc fx dislocation
First Ray Function during gait cycle. supports activity of what muscles? how much movement?
Provides stability during terminal stance and push off
Provides shock absorption during loading
Support for muscle activity of posterior and anterior tibialis, peroneus longus
Generally 20mm movement (10 each way)
First Ray anatomy. normal range relative to 2nd ray? full DF allows what? full PF allows what? stability is assisted by what muscle? how does pronated foot lead to hallux valgus and hallux rigidus? PF with inv/ev? DF with inv/ev?
metetarsal plus cuneiform = ray –> function as a stable, osseous structure
Distal met has 2 grooves for sesamoids
Approximately 22 deg for PF, DF, INV, EV. normal range is 6-10mm about and below 2nd ray
Full DF allows movement into foot flat
Full PF allows full hallux extension during propulsive phase of gait
Stability assisted by peroneal longus
pronated foot increases lateral pull of peroneus longus leading to hallux valgus and hallux rigidus
1st MTP 40-60 deg range required for gait
Primarily plantar flexes with inversion and dorsiflexes with eversion
Muscles-Lower Leg. What muscles are in each compartment?
Lateral compartment: peroneous longus and brevis
Anterior compartment: anterior tibialis, EHL, EDL, peroneous tertius
Posterior compartment: gastroc, soleus, plantaris, popliteus, FHL, FDL, posterior tibialis
Achilles Tendon. how many bursea and where? what is it convered with? what makes it prone to tendonitis/osis?
thickest and strongest tendon in the body
2 bursea (retrocalcaneal and superficial)
no synovial sheath
- peritendon covers achilles tendon (stretches 2-3cm with achilles movement: peritenonitis and vascular “watershed” (area of decreased circulation)
Muscles on plantar aspect of foot
4 layers:
1) abductor hallicus, FDB, abductor digiti minimi
2) deep portion of quadratus plantau, 4 limbricales (and FHL tendon and FDL tendon)
3) FHB, adductor hallicus (7 shaped), FDM
4) 3 plantar interossei and 4 dorsal interossei
Arches of the Foot (keystone/pillars/ windlass for each)
medial, lateral, and transverse
Allow rigid lever to flexible serious of joints
Each has a keystone at its peak, 2 pillars and a tie rod to keep pillars from separating.
Medial arch:
keystone- talar head
Pillars- calcaneous and 1-3 met heads
Windlass- plantar fascia
Lateral arch:
keystone- talo-calcaneus and calcaneo-cuboid joint
Pillars- calcaneous and 4-5 met. heads
Windlass- plantar fascia
Transverse:
keystone- middle cuneiform
Pillars- cuboid and medial cuneiform
Windlass- interosseous ligament, plantar and dorsal ligaments, peroneus longus
*loss of integrity of one really starts to stretch the others.
Medial Longitudial Arch (supported by what active elements? what active elements flatten arch?)
support formed by ACTIVE AND PASSIVE ELEMENTS
Active:
- posterior tibialis, FHL, FDL (deficiency causes decrease n MLA)
- gastrocnemius and soleus have an arch flattening effect
Stability of longitudinal arch
passive elements:
- long and short plantar ligament (calcaneo-cuboid)
- spring ligament (plantar calcaneo navicular)
- plantar fascia
Plantar Aponeurosis
central portion runs from medial process of calcaneus to the FDB
Distally fans out and attaches to subcutaneous tissues and plantar aspect of joints 2-5 (toe extension places pressure on the plantar aponeurosis)
Functions of Plantar Fascia during gait
central portion thought to bee implicated with plantar fascitis
- Toe off- Windlass effects helps form a more rigid lever for push off
- relaxes during heal strike and the first protion of stance- flattening the arch- shock absorber
- foot flat to toe off - pulled over met heads causing arch to rise
(hyper mobility can affect 1st ray –> hallux valgus b/c big toe takes on more weight)
Nerve and Arterial Components
antero-lateral aspect of the leg: anterior tibial artery, deep and superficial peroneal nerve
Posterior leg: peroneal artery, posterior tibial artery, tibial nerve
Medial ankle: posterior tibial nerve and artery divided into medial and lateral plantar artery and nerve
Dorsal Foot: dorsalis pedis artery divides and supplies toes as dorsal digital arteries, superficial and deep peroneal nerves
Plantar foot: lateral and medial plantar arteries and plantar nerves, calcaneal branch of tibial nerves (sometimes called calcaneal nerve)- digital nerves
(vasculitis affects nerve more than muscle [ischemia to nerve])
