Functional Anatomy

Question 0

Normal tibial torsion

Answer 0

15 to 25 degrees external

Question 1

Normal tibiofibular varus

Answer 1

6 degrees

Question 3

Subtalar neutral definition

Answer 3

STJ neither pronated nor supinated

Question 4

Distal tibiofibular joint is what type of joint?
convex concave?
normal movement?

Answer 4

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

Question 5

Talocrural joint is what type?
axes?
close packed/loose packed?
capsular pattern?
normal movement(OKC, CKC, for gait)

Answer 5

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

Question 6

Distal Tibio-Fibular Joint
What happens with:
foot pronation/supination/PF/DF

Answer 6

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

Question 7

Ankle Ligaments (which ones resist INV, EV, IR, ER)

Answer 7

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

Question 8

Distal Tibio Fibular Joint ligaments and Injuries

Answer 8

Ligaments:
anterior tibiofibular ligament
posterior tibiofibular ligament
transverse ligament
interosseous ligament

Syndesmotic Injuries:
high ankle sprain
syndesmotic disruption in fx and dislocation

Question 9

Talocrural joint ligaments:
Rank weakest to strongest.
Ankle instability implicated in what two things?

Answer 9

Weakest to strongest:
ATFL < PTFL < DF < Deltoid

Ankle instability implicated in:
posterior tibial tendon dysfunction and achilles tendinosis

Question 10

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?

Answer 10

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

Question 11

Sub Talar Joint Ligaments

Answer 11

Posterior talo-calcaneal ligament

Interosseous Ligament - can be damaged in ankle sprain, can contribute to excessive anterior translation of talus

Question 12

Midtarsal joint is what type of joint? describe axes. describe function. movement is dependent on what?

Answer 12

(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

Question 13

key ligaments for arch support and plantar aspect support of mid tarsal join

Answer 13

Long plantar- calcaneo cuboid + 2,3,4 met

Short plantar- calcaneo cuboid

Plantar calcaneonavicular (spring ligament)

Plantar aponeurosis

Question 14

Mid-Tarsal Joint ligaments

Answer 14

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

Question 15

Cuneonavicular joint (intertarsal joint)

Answer 15

synovial modified ovoid

PF, DF, INV, EV

closed packed = supination

open packed = mid way between pronation and supination

convex navicular with concave cuneiforms

Question 16

cuneometatarsal

Answer 16

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

Question 17

cubometetarsal

Answer 17

sometimes called Lisfranc

modified sellar synovial joint considered together

cuboid articulates with 4th and 5th mets distally

Question 18

Cubonavicular

Answer 18

functions as a syndesmosis

if synovial, capsule is contguous with cuneonavicular joint capsule

dysfunction begins with pes planus deformity

Question 19

intercuneiform and cuneocuboid joints

Answer 19

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

Question 20

Forefoot consists of what? what is the 1st ray?

Answer 20

3 general regions:

1) tarso-metetarsal (lisfranc)
2) MTP
3) Interphalangeal
- 1st ray articulation: medial cuneiform and 1st metatarsal

Question 21

Intermetatarsal Joints are what type of joint?

movements? purpose?

Answer 21

Modified ovoid joints

Movements confined to dorsal/plantar glide

Allows fanning and folding motion of foot

Question 22

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?

Answer 22

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

Question 23

Interphalangeal joints are what type of joint? how many DoF?closed/open packed positions?capsular pattern?

Answer 23

synovial hinge joints with 1 DoF

Closed packed: full extension

open packed: slight flexion

Capsular pattern = more limitation of flexion than extension

Question 24

What are accessory Bones? give 2 examples.

Answer 24

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

Question 25

Key ligaments for tarso-metatarsal joint

Answer 25

3 Ligaments 1) Dorsal 2) Plantar 3) Interosseous - prevent joint separation - injured in lisfranc sprain and lisfranc fx dislocation

Question 26

First Ray Function during gait cycle. supports activity of what muscles? how much movement?

Answer 26

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)

Question 27

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?

Answer 27

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

Question 28

Muscles-Lower Leg. What muscles are in each compartment?

Answer 28

Lateral compartment: peroneous longus and brevis Anterior compartment: anterior tibialis, EHL, EDL, peroneous tertius Posterior compartment: gastroc, soleus, plantaris, popliteus, FHL, FDL, posterior tibialis

Question 29

Achilles Tendon. how many bursea and where? what is it convered with? what makes it prone to tendonitis/osis?

Answer 29

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)

Question 30

Muscles on plantar aspect of foot

Answer 30

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

Question 31

Arches of the Foot (keystone/pillars/ windlass for each)

Answer 31

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.

Question 32

Medial Longitudial Arch (supported by what active elements? what active elements flatten arch?)

Answer 32

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

Question 33

Stability of longitudinal arch

Answer 33

passive elements: - long and short plantar ligament (calcaneo-cuboid) - spring ligament (plantar calcaneo navicular) - plantar fascia

Question 34

Plantar Aponeurosis

Answer 34

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)

Question 35

Functions of Plantar Fascia during gait

Answer 35

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)

Question 36

Nerve and Arterial Components

Answer 36

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])