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functional anatomy of the

foot and ankle

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functional anatomy of the

foot and ankle

Edward P. Mulligan, MS, PT, SCS, ATCVP, National Director of Clinical Education – HealthSouth CorporationClinical Instructor – UT Southwestern Physical Therapy DepartmentGrapevine, TX

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The contents of this presentation are copyrighted © 2002 by continuing ED. They may not be utilized, reproduced, stored, or transmitted in any form or by any means, electronic or mechanical, or by any information storage or retrieval system, without permission in writing from Edward P. Mulligan.

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Objectives

Following completion of this study, the participant will be able to:identify the bony anatomy of the leg, foot, and ankleidentify the axis of motion and accessory motions of the joints of the leg, foot, and ankleidentify the ligamentous, vascular, and nervous anatomy of the leg, foot, and ankleidentify the muscular anatomy of the leg, foot, and ankleexplain the muscular function of the leg, foot, and ankle during gaitpalpate the bony and soft tissue structures of the leg, foot, and ankle

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leg anatomy

Tibia– triangular shape with medial, lateral and

posterior surfaces– interosseus membrane connects the tibia

to the fibula– distally, articulates with the talus

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anterior view

This is an anterior view

Distinct medial, lateral, and posterior surfaces with anterior tibial crest representing the apex of the triangle

Strong, tough, interosseus membrane connects the tibia to the fibula

distally, the tibia articulates with the talus

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leg anatomy

Fibula– long, thin bone located posterolateral to

the tibia– little weight bearing function; mainly for

muscle attachment– distally, the medial surface articulates with

the tibia and talus

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posterior view

This is a posterior view:

Fibula is a long, thin bone positioned at about a 45 degree angle posterolateral to the tibia

little weight bearing function; mainly for muscle attachment

distally, the medial surface articulates with the tibia and talus

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foot anatomy

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C

T

NC1

Cu

C

C2 C3

Metatarsals

Phalanges

forefoot

midfootrearfoot

Superior (dorsal)

Antetior(distal)

Posterior (proximal)

Inferior (plantar)

Directional terminology

Superior = dorsal

Inferior = plantar

Posterior = proximal

Anterior = distal

The foot can be divided into three sections

Rearfoot = hindfoot

Midfoot

Forefoot

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foot-ankle articulations

C = Calcaneus C1-2-3 = CuneiformsT = Talus Cu = CuboidN = Navicular Mt = Metatarsal

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C

1

C3-2-1

Cu N

T

54 3 2Talocrural (ankle) joint

Talonavicular (midtarsal) joint

Tarsometatarsal joint

1st Metatarsophalangeal joint

Talocalcaneal (subtalar) joint

T

C

NC1

1st Mt

1st PP

Talocrural (ankle) joint

Talocalcaneal (subtalar) joint

Talonavicular (midtarsal) joint – calcaneocuboid joint not pictured but is on the lateral side of the jont

Tarsometatarsal (LisFranc) joint - Cuneiforms articulate with mets 1-3 and cuboid articulates with mets 4-5

1st metatarsophalangeal joint

Sustaniculum tali on medial calcaneus and is origin of calcaneonavicular (spring ligament)

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Lateral pillar Medial pillar

FF

CC

TT

MtMtCuCu

TBTB

CC

NN

MtMtMCMC

TT

Feiss Line

F – Fibula

T – Talus

Cu – Cuboid

C – Calcaneus

Mt – Metatarsal

TB –Tibia

N – Navicular

MC – Medial Cuneiform

Navicular Tuberosity should lie on the line that connects the medial malleolus and medial 1st metatarsal head in both WBing and NWBing postures. This line is called the Feiss line

Note that the lateral longitudinal arch is lower than the mediallongitudinal arch

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tibiofibular joint

Superior – plane synovial joint– fibular head articulating with posterolateral

aspect of tibial condyle

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Inferior – syndesmosis with fibroadipose tissue

connecting tibia and fibula– reinforced by anterior and posterior

tibiofibular ligaments

While geographically closer to the knee, the tibfib joint is functionally associated with the foot and ankle

Interosseous membrane binds tibia an fibula together and is the origin for many of the muscles that effect the foot and ankle

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tibiofibular accessory motions

Plantarflexion fibula slides caudally and lateral malleolus rotates

medially causing approximation of TCJ

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Dorsiflexion fibula slides cephalically and lateral malleolus rotates

laterally to spread the mortise and accommodate the wider portion of the anterior talus

Accessory motions are defined as involuntary arthrokinematic spin, glide, or roll at the joint surfaces that must accompany full, pain-free osteokinematic motion.

Clinically, lack of dorsiflexion range may be partially associated with tibiofibular hypomobility

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tibiofibular accessory motions

Supination

fibula slides distally and posteriorly

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Pronation

fibula slides proximally and anteriorly

Distal tibfib accessory motions

Supination – fibula slides distally and posteriorly with external rotation of the lower leg

Pronation – fibula slides proximally and anteriorly with internal rotation of the lower leg

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Part 2 – Talocrural Joint

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talocrural joint

• synovial mortise joint

• concave tibial plafond and convex talar dome

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• supported by:

• Anterior talofibular ligaments• Posterior talofibular ligaments • Calcaneofibular ligament • Deltoid ligament

Referred to as a mortise joint because of its resemblance to a wood joint used by carpenters

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talocrural joint ligamentslateral view

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anterior tibiofibular

anterior talofibularcalcaneofibular

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1 - Ant TibFib ligament injured in “high” ankle sprain. The mechanism of injury is typically a rotational injury when tibia IR and foot abducts. Evaluated by Kleiger test

2 - ATFL lies in the hollow depression just superior to EHB (called the sinus tarsi) and resists anterior anterior talar translation when plantarflexed; resists calcaneal inversion when ankle is plantarflexed

2 - ATF is most commonly injured ankle ligament and evaluated by the anterior drawer test

3 - CFL is typically about 100 degrees inferior and resists calcaneal inversion with the ankle dorsiflexed

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talocrural joint ligamentsposterior view

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posterior talofibular

posterior tibiofibular

Posterolateral lignaments are rarely injured

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talocrural joint ligamentsmedial view

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Fan shaped medial “deltoid” ligament

Anterior tibiotalar

Tibionavicular Tibiocalcaneal

Posterior tibiotalar

Delotid resists ankle eversion and is typically injured with a hyperpronation mechanism (calcaneal eversion)

Medial sprains are unusual because the lateral malleolous provides a bony block to extreme eversion and the strength of the deltoid ligament

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talocrural joint axis

posterolateral inferior to anteromedial superior

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approximately 10-15° off the frontal and transverse plane

TRIPLANAR MOTION

PF – Add – Inv

DF – Abd - Ever

Posterior View: axis is lateral and inferior to medial superior

Dorsal view: axis is posteior to anterior

Motion always occurs perfectly perpendicular to the axis

Sagittal plane plantar-dorsiflexion are primary motions because the axis is nearly parallel to both the frontal and transverse planes

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©©

Inversion-eversion

Abduction - Adduction

PLANTAR-DORSIFLEXION Texas

NJ

talocrural joint motion analogy

Arkansas

Sagittal plane plantar-dorsiflexion are primary motions because the axis is nearly parallel to both the frontal and transverse planes

A lot (Texas size) of PF-DF motion

Some (Arkansas size) Ab-Add motion

A little (New Jersey size) Inv-Eversion motion

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fluoroscopic talocruralsagittal plane motion

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Fluoroscopic motion movie clip of the talocrural joint available for download

Sagittal plane plantar-dorsiflexion on talocrural joint axis

PLANTAR-DORSIFLEXIONAbduction-Adduction

Inversion-Eversion

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talocrural joint range of motion

20-0-50° sagittal plane plantar-dorsiflexion

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AAOS standard – 20-0-50 degrees

20 degrees dorsiflexion is with knee flexed to put gastroc on slack

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talocrural joint

Resting Positionslight plantarflexion

10-15°

Closed Pack Positionmaximal dorsiflexion

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Resting position – ligaments on slack; maximal joint space; treatment position

Closed Pack Position – ligaments taught; talus engaged in mortise; dynamically stable; testing position

Talus wider anteriorly than posteriorly and fully engages the mortise in extreme dorsiflexion

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talocrural accessory motion

anterior talar glide with plantarflexion

dorsiflexion

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plantarflexion

posterior talar glide with dorsiflexion

Talus moves in NWB – convex talus glides and rolls in opposite directions

ConcaveTibia moves in WB - anterior with dorsiflexion

- posterior with dorsiflexion

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Part 3 – Subtalar Joint

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subtalar joint

• talocalcaneal synovial articulation with uniaxial oblique hinge

• couples function of foot with rest of kinetic chain

• talus has no muscular attachments

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ER-supination

IR-pronation

Talus articulates with three facets on the calcaneus

Smaller, relatively flat anterior and middle facets and the larger, concave talar posterior facet

Stand up and rotate – feel the subtalar motion that accompanies lower extremity rotation

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subtalar joint ligaments

Interosseus talocalcaneal ligament

Posterior talocalcaneal ligament

Lateral talocalcaneal ligament

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Exploded View

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subtalar joint axis orientation

16° off the sagittal plane42°off the frontal plane

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42º

16º

To understand subtalar joint motion you must define the axis about which motion will take place

Average of 16 degrees medial to sagittal plane and up 42 degrees from the frontal plane

Frontal plane orientation varies from 20-60 degrees

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subtalar joint axis of motion

Axis runs from

dorsal-medial-distalto

plantar-lateral-proximal

©PLP

DMD

Same orientation as TCJ – anteromedial superior to posterolateralinferior; only in different proportions

Dorsal (superior) – Medial – Distal (anterior)

Plantar (inferior – Lateral – Proximal (posterior)

Primary motion is frontal plane inversion-eversion

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©

INVERSION-EVERSION

Abduction-Adduction

plantar-dorsiflexion

Texas

Arkansas

NJ

subtalar joint motion analogy

A lot of (Texas size) Inverison-Eversion

Some (Arkansas size) Ab-Adduction

Little (New Jersey size) pf-df because axis is so close to sagittal plane

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subtalar joint motion

approximate one to one relationship with calcanealinversion/eversion and tibial internal-external rotation

With low level of inclinationincreased calcaneal mobility

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With high level of inclinationdecreased calcaneal mobility

Clinical Consideration:

If the STJ axis is at the typical 40-45° pitch then there is appoximatleya one-to-one relationship between calcaneal inversion-eversion and tibial internal-external rotation

Meaning that for every degree of IR there is one degree of calcanealeversion as a component of STJ pronation

As the axis moves toward the transverse plane – Lower Level

greater risk for hypermobility, overuse injures – tendinitis, fasciitis; pf syndrom

As the axis moves more parallel to the long axis of the tibia - High level – greater risk for hypombobility injuries – poor shock absorption and prxomail injuries – stress fractures; LBP

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STJ range of motion

20° – 0 – 10°

at least 8-12° of supination and 4-6°of pronation required for normal gait

©

20ºinv

10ºever

Inversion Eversion

20-0-10 degree is normal STJ motion

at least 8-12° of supination and 4-6° of pronation required for normal gait

Rule of 1/3rds

Podiatrists use this mathematical model to determine STJN position.

1. Determine the total STJ ROM and divide by 3

2. Move this amount from end range eversion to locate the STJ neutral position

3. Example: 6° eversion + 30° = 36° of total motion/3 = 12°

4. 6° eversion - 12° = 6° inverted as STJ neutral

Works well as an average of the entire population but lacks individual validity. Subsequently, recommend palpaltion method for determining individual STJ neutral position.

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subtalar joint

Closed Pack Position

full supination

Open Pack Position

subtalar joint neutral

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Full supination offers maximaly stability as during propulsion

STJ neutral provides maximal mobility as at heel strike into forefootlloading where terrain adaptation must occur

STJ neutral - 1/3 of the distance from full eversion of total STJ range

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subtalar joint accessory motions

convex portion of calcaneus slides laterally with

inversion

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INV EVER

convex portion of calcaneus slides medially with

eversion

Convex posterior facet on calcaneus is up to 70% of the surface area of the STJ) articulation

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Part 4 – Midtarsal Joints

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midtarsal joint(transverse tarsal joint)

two joints functioning together (talonavicular and calcaneocuboid articulations) about two common axes of motion (longitudinal and oblique)

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ligamentous support from calcaneo-navicular (spring), deltoid, dorsal talonavicular, and calcaneocuboid ligaments (long and short plantar) ligaments

Also called Chopart’s (sho-par) Joint after the French surgeon who first described an amputation at this level of the foot

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calcaneonavicular ligament

Spring Ligament

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Spring ligament runs from the sustanaculum tali to the naviculartuberosity and supports medial longitudinal arch by cradling or supporting the talus and navicular

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dorsal-plantar ligamentous support

Long and short plantar ligamentsDorsal talonavicular

ligament

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Superior View Inferior View

Long – calcanenus to base of lateral metatarsals

Short - calcaneocuobid

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plantar fascia

• Dense multilayered fibrous connective tissue

• Originates at the medial calcaneal tuberosity

• Inserts into the plantar plates of the MTP joints and bases of the proximal phalanges

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Dense multilayered fibrous connective tissue

Originates at the medial calcaneal tuberosity

Inserts into the plantar plates of the MTP joints and bases of the proximal phalanges

Provides truss support and assists with propulsion through windlass mechanism in the late stance phase of gait.

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midtarsal joint oblique axis of motion

Equally angulated from transverse and sagittal planes allowing coupled motions of plantarflexion-adduction and dorsiflexion-abduction

52° off transverse plane and 57° off sagittal plane

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52º

57º

Ab-Adduction of foot occurs on the 52 degree axis

Plantar-dorsiflexion of mid-foot occurs on the 57 degree axis

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midtarsal joint longitudinal axis of motion

15° off transverse plane and 9° off sagittal plane

Parallel to the transverse and sagittal planes allowing only frontal plane motion of inversion and eversion

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15º

9º

Inversion-Eversion motion of mid-foot occurs on the longitudinal axis

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midtarsal joint motion vs. position

No clinically reliable method of quantifying the amount ofmidtarsal ROM. Midtarsal joint motion is dictated by the

position of the subtalar joint.

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The position of the midtarsal joint is dictated by ground reaction forces andmuscular forces, motion of the joint isdetermined by the position of the subtalar joint.

Rhetorical question – “How do you measure midtarsal joint motion?” –obviously we can’t

We tend to subjectively qualify mobility instead of trying to quantify the amount of angular motion at the midtarsal joints

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midtarsal joint axes relationship

When the STJ is pronated the two axes of the MTJ diverge (become more parallel and allow motion)

When the axes converge during supination, the MTJ locks, allowing little motion

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Root’s and Weed’s classic explanation of how midtarsal joint axe’s relationship can be both a flexible adaptor to terrain and a rigid lever for propulsion

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midtarsal joint “locking”

Root and Weeds contention of converging axis may be challenged by the fact that:

talonavicular joint is a ball and socket joint with an infinite number of axes

consequently, at any one time an axis is both parallel and askew to the calcaneocuboid joint

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If both parallel and askwed simultaneously, the axes can never converge or diverge

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midtarsal joint “locking”

Anterior facet of the talus articulates with the cuboid in supination

talus acts as a bony block to cuboid motion

Glasser, 1999

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Anterior facet of the talus articulates with the cuboid in supination as evidenced by presence of hyaline cartilage at the talocuboid interface

talus acts as a bony block to cuboid motion when the STJ is supinated

Clinically, it is simply important to assess if midtarsal mobility is increased with pronation and decreased (stiffened) with supination

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midtarsal joint

Closed Pack Position

Subtalar joint supination

Resting Position

Subtalar joint neutral

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Rember that motion availability is dependent upon the position of the STJ

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midtarsal joint accessory motion

SUPINATIONdorsal glide of the navicular on the talus

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PRONATIONplantar glide of the navicular on the talus

supination

pronation

Functionally, supination is assisted by posterior tib pulling the navicular up and by the peroneals pulling the navicular down with the eversion component of STJ pronation

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Part 5 – First Ray - 1st MTP Joint

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first ray

functional articulation consisting of the 1st metatarsal, medial cuneiform, and navicular

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axis angulated 45° from the frontal and sagittal planes and parallel to transverse plane

distal-lateral to proximal-medial

DL

PM

Scapulohumeral analogy – like the scapula gliding across the thorax, the first ray is not a typical diarthrodial joint but has important functional contribution

Distal lateral (instead of distal-medial) to Proximal medial(instead of proximal-lateral)

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first ray motion

coupled motion of

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dorsiflexion and inversion

plantarflexion and eversion

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PRONATION– medial longitudinal arch lowers – increased 1st ray mobility – peroneus longus important stabilizer

Subtalar Joint Effect on 1st Ray

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SUPINATION– medial longitudinal arch elevation – increased 1st ray stability

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1st ray accessory motion

1st ray motion of plantar-dorsiflexion is influenced by the subtalar joint’s position

1st ray motion is increased with pronation and decreased with supination

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Normal mobility is .5 to 1 cm (thumb's width) in plantar and dorsal directions

Method by which to determine mobility of first ray (hypo or hyper)

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1st metatarsophalangeal joint

articulation between 1st metatarsal and the

1st proximal phalanx

sesamoids articulate with plantar metatarsal head

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1st MTP joint axis of motion

horizontal axis allowing sagittal plane motion of plantar-dorsiflexionvertical axis allowing abduction-adduction

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20-30° with 1st ray stabilized60-70° when 1st ray allowed to plantarflex

horizontal (medial to lateral) axis allowing the sagittal plane motion of plantar-dorsiflexion

vertical (superior to inferior) axis allowing abduction-adduction

20-30° with 1st ray stabilized60-70° when 1st ray allowed to plantarflex

Common to have less 1st MTP dorsiflexion range – implications to many pathologies.

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1st MTP joint

Closed Pack Position

full dorsiflexion

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Resting Position

slight plantarflexion

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1st MTP joint accessory motion

PLANTARFLEXION

Plantar glide of proximal phalanx

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DORSIFLEXION (extension)

Dorsal glide of proximal phalanx

PF – plantar glide of proximal phalanx or dorsal glide of metatarsal

DF – dorsal glide of proximal phalanx or plantar glide of metatarsal

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Bony palpation landmarks

1st Met Head1st Metatarsal1st Cunieform 2nd Cuneiform3rd CuneiformNavicular TuberosityTalar HeadMedial MalleolusSustentaculum TaliCalcaneus

5th MetatarsalStyloid ProcessCuboidSinus TarsiTalar Dome CalcaneusLat. MalleolusMedial Calcaneal Tuberosity

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1st Met Head – bunions, gout, sesamoidsFirst MetatarsalMedial Cunieform – articulates with 1st met2nd Cuneiform – articulates with 2nd met3rd Cuneiform – articulates with 3rd metNavicular Tuberosity – landmark of feiss lineTalar Head – palpated for STJ neutral (no muscle attachments) – more prominent with pronationSustentaculum Tali – large medial extension of calcaneus; fingers width below medial malleolus; origin of spring ligamentMedial Malleolus -Calcaenus5th MetatarsalStyloid Process at Base of 5th – insertion of peroneus brevisCuboid – notch for peroneus longusSinus Tarsi – EHB origin; area of ATF ligamentCalcaneusLateral MalleolusTibiofibular SynostosisTalar Dome – can palpate anterior talus in the sinus tarsi with plantarflexion/inversionMedial Calcaneal Tuberosity – origin of plantar fasciaMet Heads

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Lower Leg Muscles

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muscular anatomy

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anterior compartment

Muscles– TA, EHL, ED, PT

General Function– Ankle df; toe extension

Innervation– Deep peroneal nerve– L4,5 S1

Blood Supply– Anterior Tibial Artery

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PTATEHLEDL

anterior compartment muscle function

EverLatDorsiflexPTLat

Med

STJ Axis

EverExtendED

ExtendEHL

InvDorsiflex

Anterior

AT

TCJ Axis

Mm STJ Axis

TCJ Axis

©x-section of left lower leg

medial

lateral

anterior

posterior

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Anterior Tibialis

Origin – lateral tibial condyle; proximal 2/3 of anterolateral

surface of tibia; interosseous membrane

Insertion– medial & plantar surface of base of 1st metatarsal – medial & plantar surface of the cuneiform

Action– strongest dorsiflexor; inverts & adducts the foot

©

Origin is on the laterallateral tibial condyle; upper 2/3 of anterolateralsurface of tibia; interosseous membrane

Anterior tib wraps around the foot to insert on the medial & plantar surface of base of 1st metatarsal and medial cuneiform

Anterior tibi is the strongest dorsiflexor; inverts & adducts the foot

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Extensor Hallicus Longus

Origin – middle half of anterior shaft of fibula;

interosseous membraneInsertion

– dorsal surface of base of proximal and distal phalanx of hallux

Action – extends distal phalanx of big toe; weak

dorsiflexor; weak inversion & adduction

©

Lateral to the Anterior tib

Questionable inversion/eversion effect as tendon is on the STJ axis

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Extensor Digitorum

Origin– lateral condyle of the tibia; upper ant.

surface of fibula; interosseous membraneInsertion

– dorsal surface of the bases of the middle & distal phalanxes of the 2nd-5th rays

– via 4 tendons creating a fibrous expansionAction

– extends the lateral 4 toes; weak dorsiflexor & evertor of foot

©

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Peroneus Tertius

Origin– distal 1/3 of anterior fibula; distal &

lateral aspect of extensor digitorum

Insertion– dorsal surface of base of 5th metatarsal

Action– extends the 5th toe; weak dorsiflexor &

evertor of foot

©

Origin is on lower 1/3 of anterior fibula; distal & lateral aspect of extensor digitorum and inserts on top of the dorsal surface of base of 5th metatarsal

Action - extends the 5th toe; weak dorsiflexor & evertor of foot

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lateral compartment

©

Muscles– Peroneus Longus and Brevis

General Function– Ankle pf; STJ eversion; plantarflexion

of 1st rayInnervation– Superficial peroneal nerve– L4,5 S1

Blood Supply– Peroneal branch from posterior tib

artery

no arteries in lateral compartment apart from a muscular branch to the peroneal muscles from the peroneal artery, a branch of the posterior tibial artery

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lateral compartment muscular function

©

EverLatPlantarflexPosteriorPBPL

STJ Axis

TCJ Axis

Mm

TCJ Axis

STJ Axis

Posterolateral quadrant

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Peroneus Longus

Origin – head of the fibula; proximal 2/3 of lateral

fibula

Insertion – plantar surface of cuboid; base of 1st &

2nd metatarsal; plantar surface of medial cuneiform

Action – eversion & abduction of the foot;

plantarflexion of the 1st ray

©

Originates from the head head and the upper 2/3 of lateral fibula

Passes through the cuboid notch or pulley on its way to it’s insertion at the base of 1st & 2nd metatarsal; plantar surface of medial cuneiform

Action - eversion & abduction of the foot; plantarflexion of the 1st ray

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Peroneus Brevis

Origin – distal 2/3 of lateral fibula

Insertion– styloid process at base of 5th

metatarsal Action

– eversion & abduction of the foot; weak plantarflexion of foot

©

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superficial posterior compartment

©

Muscles– Gastroc, soleus, and plantaris

General Function– Ankle pf; STJ supination

Innervation– Tibial nerve which is derived from

L5-S1 nerve roots

Blood Supply– Posterior Tibial Artery

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superficial posterior compartment muscular function

©

SoleusInvMedPlantarflexPosterior

Gastroc

STJ Axis

TCJ Axis

Mm

TCJ Axis

STJ Axis

Posteromedialquadrant

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Gastrocnemius

Origin– medial head: just above medial condyle

of femur – lateral head: just above lateral condyle of

femurInsertion

– calcaneus via achilles tendonAction

– plantarflex the ankle – knee flexion (when not weight bearing)

©

Gastroc is a phasic (fast twitch) muscle that is better recruited with high intensity activity

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Soleus

Origin– upper fibula – soleal line of tibia (upper 1/3 of

posterior tibia

Insertion– calcaneus via achilles tendon

Action– plantarflex the ankle

©

Soleus is a tonic or slow twitch predominant muscle

Soleal line located on upper 1/3 of posterior tibia

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deep posterior compartment

©

Muscles– PT, FDL, FHL

General Function– Ankle pf; STJ inversion; toe flexion

Innervation– Tibial nerve– L5-S1

Blood Supply– Posterior Tibial Artery

FHL

FDLPT

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deep posterior compartment muscular function

©

Inv

Med

Plantarflex

Posterior

PTInvPlantarflexFHLInvPlantarflexFDL

STJ Axis

TCJ Axis

Mm

TCJ Axis

STJ Axis

FHL

FDLPT

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Posterior Tibialis

Origin – Postermedial portion of the proximal tibia;

interosseous membrane; medial surface of fibula

Insertion (broad expansive insertional area)– navicular tuberosity (principle); all three

cuneiforms (plantar surface); bases of 2nd-4th metatarsals; cuboid; sustentaculum tali of calcaneus

Action – stabilizes ankle; inverts and adducts the foot;

weak ankle plantarflexor; control and reverse pronation ©

Posterior tib origin palpable a hand’s width superior to medial malleolus; tendon palpable just posterior to medial malleolus with resistance plantarflexion and inversion

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Flexor Digitorum Longus

Origin: – posterior surface of tibia and crural fascia

Insertion– plantar surface of bases of the 2-5th

distal phalanges Action:

– primarily flexes 2nd - 5th toes – weak ankle plantarflexor and inversion &

adduction of foot

©

Crural fascia also known as interosseous membrane

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Flexor Hallicus Longus

Origin: – posterior, inferior 2/3 of fibula; interosseous

membrane; – crural fascia & posterior intermuscular septum

Insertion– plantar surface of distal phalanx of hallux

Action: – flexes big toe (hallux); weak plantarflexion of the

foot; weak inversion & adduction of foot

©

Origin is from posterior, lower 2/3 of fibula; interosseous membrane; crural fascia & posterior intermuscular septum

Inserts onto the plantar surface of the big toe

Action: flexes big toe (hallux); weak plantarflexion of the foot; weak inversion & adduction of foot

Trivia Question: What kind of athlete is susceptible to FHL tendinitis?

Commonly injured in ballet dancers

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Foot Intrinsic Muscles

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Intrinsic Muscles of the Foot

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Superficial First Layer

ADMADMFDBFDB

AHAH

•Muscles that originate and insert within the foot

•foot muscles have gross rather than precise functions compared to the hand

•many muscles in the foot have names that imply a function they rarely perform, or, for some individuals, are unable to perform

•however, and somewhat ironically, loss of function or surgical alteration of these muscles can result in the development of a foot deformity

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Abductor Hallicus

Origin – medial process of calcaneal tuberosity;

Insertion – medial aspect of base of proximal

phalanx of hallux Action

– flexes the big toe (primary action); may assist in abduction of big toe

Blood Supply – medial plantar artery

Innervation – medial plantar nerve, L5,S1

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•Muscles which produce transverse plane motion (ab/adduction) in the foot are named relative to the midline of THE FOOT, not the midline of the body

•The ‘midline’ of the foot is a line passing through the heel and the 2nd toe

•Abduction of the big toe is a medial motion while abduction of the little toe is a lateral motion

•Weakness of AH may contribute to hallux valgus

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Flexor Digitorum Brevis

Origin – medial and lateral process of calcaneal

tuberosity; plantar aponeurosisInsertion

– both sides of the bases of the middle phalanx of rays 2-5 with each of the 4 tendons splitting to form tunnel for FDL

Action– flexes toes 2-5

Blood Supply – medial plantar artery

Innervation– medial plantar nerve, L5,S1

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Originates from the medial and lateral process of calcaneal tuberosityand plantar fascia

Insertion is from both sides of the bases of the middle phalanx of rays 2-5 with each of the 4 tendons splitting to form tunnel for FDL

Action – flexes the less four toes

Blood Supply is from medial plantar artery

Innervated by the medial plantar nerve, L5,S1

Origin is the site of calcaneal spurs typically associated with plantar fascitis

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Abductor Digiti Minimi

Origin – lateral & medial processes of the

calcaneal tuberosity and plantar aponeurosis

Insertion– lateral aspect of base of proximal

phalanx of 5th ray Action

– abducts and assist in flexing the 5th toe Blood Supply

– lateral plantar artery Innervation

– lateral plantar nerve, S1,2

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Most lateral of the three muscles in the superficial layer

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Intrinsics Muscles of the Foot

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Second Layer– FHL– FDL– Quadratus Plantae– Lumbricales

Both intrinisc muscles (quadratus plantae and the lumbricales) are functionally related to the FDL

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FHL - FDL

Flexor Hallicus Longus

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Flexor Digitorum Longus

From posterior deep compartment

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Quadratus Plantae

Origin– medial head: medial calcaneus – lateral head: lateral calcaneus & long plantar

ligamentInsertion

– lateral margin of tendon of FDL and may send slips into the distal tendons

Action– assists FDL in flexing the distal phalanges of toes

2-5; corrects FDL from pulling toes mediallyBlood Supply

– lateral plantar arteryInnervation

– lateral plantar nerve, S1,2

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The action or line of pull corrects the natural medial vector that the FDL would create if acting alone

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Lumbricales

Origin– from tendons of FDL:

1st: medial aspect of tendon to 2nd ray 2nd-4th: two heads between the tendons in which they lie

Insertion– extensor tendons of EDL on dorsal footAction

– flex proximal phalanges at 2-5 MTP; extend middle & distal 2-5 phalanges at IP

Blood Supply – 1st: medial plantar artery; 2nd-4th: lateral plantar arteryInnervation

– 1st: medial plantar nerve, L5,S1; 2nd-4th: lateral plantar nerve, S1,2

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Lumbricale flex the MTPs and extend the PIP and DIPs

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Intrinsics Muscles of the Foot

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Third LayerFlexor Hallicus BrevisAdductor HallicusFlexor Digiti Minimi Brevis

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Flexor Hallicus Brevis

Origin – plantar aspect of the cuboid and lateral

cuneiformInsertion

– medial and lateral aspect of base of proximal phalanx of hallux

Action– flexes hallux at MTP

Blood Supply– medial plantar artery

Innervation– medial plantar nerve, L5,S1

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Insertion is on both sides of the base of the 1st proximal phalanx

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Adductor Hallicus

Origin– oblique head: base of 2nd-4th metatarsals &

long plantar ligament– transverse head: deep transverse metatarsal

ligament & plantar ligaments at MTP jointsInsertion

– lateral aspect of base of proximal phalanx of hallux

Action – adduction and flexion of hallux at MTP

Blood Supply– lateral plantar artery

Innervation– lateral plantar nerve, S1,2

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Often become contracted with hallux valugus and is released as a part of soft tissue realingment procedures with bunions

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Flexor Digiti Minimi Brevis

Origin– base of 5th metatarsal – digital sheath of peroneus longus

Insertion– lateral aspect of base of 5th proximal

phalanxAction

– flexes the 5th toe at MTP Blood Supply

– lateral plantar artery Innervation

– lateral plantar nerve, S1,2

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Intrinsics Muscles of the Foot

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Deepest Fourth LayerPlantar InterosseiDorsal Interossei

Deepest fourth layer contains the plantar and dorsal interossei

Similar function as in hand except the reference digit is the 2nd digit instead of the 3rd in the hand

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Plantar Interossei – 3 muscles

Origin– medial aspect of 3rd-5th metatarsals (each

muscle has a single head) Insertion

– medial aspect of base of proximal phalanx of the same ray (3rd-5th rays)

Action – adduct toes 3-5 and flex toes 3-5 at MTP

Blood Supply– lateral plantar artery

Innervation– lateral plantar nerve (deep branch), S1,2

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Dorsal Interossei – 4 muscles

Origin– from both metatarsals between which they lie

Insertion– base of proximal phalanx closest to the axis of

the foot (2nd ray) Action

– abduct toes 2-4 – flexes toes 2-4 at MTP

Blood Supply– lateral plantar artery

Innervation– lateral plantar nerve (deep branch), S1,2

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Interossei Function Pneumonic

PAD– Plantar Interossei ADduct

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DAB– Dorsal Interossei ABduct

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Extensor Hallicus Brevis

Origin– upper anterolateral calcaneus and inferior extensor

retinaculumInsertion

– base of proximal phalanx of hallux Action

– extends hallux Blood Supply

– dorsalis pedis artery Innervation

– deep peroneal nerve, L4,5

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Some consider this muscle to anatomically be a part of the Extensor Digitorum brevis

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Extensor Digitorum Brevis

Origin – upper anterolateral calcaneus and inferior extensor

retinaculumInsertion

– middle & distal phalanges of 2nd-4th rays (via EDL) Action

– extends 2nd-4th rays Blood Supply

– dorsalis pedis artery Innervation

– deep peroneal nerve, L4,5

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Same origin as extensor hallicus brevis

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Muscle Action in Gait

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muscular function in gait

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Contrast the open kinetic chain muscular function as dictated by the tendon’s location relative to axes with their functional responsibilities in gait

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Muscular Function in GaitAnterior Group

Tibialis Anterior:– concentric function in swing phase and

eccentric function in stance– assist in ground clearance, controls forefoot

loading and midstance pronation

Long Extensors: – hold the oblique axis of the MTJ in a pronated

position at heel strike and assist controlled deceleration of forefoot loading and midstance pronation

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Long Extensors = EHL and EDL

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Muscular Function in GaitPosterior Deep Group

Posterior Tibialis: – controls STJ pronation at heel strike and reverses it

through midstance– maintains stability of the MTJ in the direction of

supination around the oblique axis during stance phase Flexor Digitorum Longus:

– stabilizes the foot as a weight bearing platform for propulsion.

– Works antagonistically with the intrinsics.– supports the medial archFlexor Hallicus Longus:– functions in concert with the other posterior deep

muscles, specifically stabilizing the 1st ray during propulsion and supporting the medial arch.

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Muscular Function in GaitPosterior Superficial Group

Gastroc-Soleus:active throughout the stance phase of gaitat heel strike, eccentrically decelerate tibial IR & forward progression of the tibia over the foot. Gastroc decelerates femoral IR while the soleus assists in tibial IR deceleration.during midstance and heel off, concentrically supinating the subtalar joint, externally rotating the tibia, and plantarflexing for push off.gastroc contributes to smooth knee extension by maintaining tension on the knee while the knee extends in midstance

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Muscular Function in GaitLateral Group

Peroneus Longus – provides support to the transverse and lateral

longitudinal arches– actively stabilizes the 1st ray– transfers body weight from lateral to medial

during stance

Peroneus Brevis – functions in concert with the peroneus longus– stabilizes the calcaneocuboid joint allowing the

peroneus longus to work efficiently over the cuboid pulley

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Muscular Function in Gait

Intrinsics

EDH/EDL

Posterior Tib

Soleus

Gastroc

FHL

Concentric Eccentric

Peroneals

Loading Phase

FDL

Anterior Tib

SwingPropulsionMidstance

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Anterior to

Deep to

Superficial to

Lateral

Compartment

firing

Left LegAnterior

Superficial

Deep

Lateral

Tibia

Fibula

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Neurovascular Anatomy

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Innervation and Vascular Anatomy of the Leg -Ankle - Foot

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Anatomical Review of Segmental Innervation

Motor control of spinal cord levels

Nerve root from L4 spinal cord level provide SJT inverter motor control

Nerve root from L5 spinal cord level provides TCJ dorsiflexion motor control

Nerve root from S1 spinal cord level provides TCJ plantarflexion or STJ Inversion motor control

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Nerve Anatomy

sciatic– common peroneal– tibial

common peroneal– superficial – deep

tibial– medial and lateral

calcaneal nerves– medial and lateral

plantar nerves

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Superficial Peroneal

branch of common peroneal

passes down anterior compartment of leg, then branches off into:

medial dorsal cutaneous nerve

intermediate dorsal cutaneous nerve

Deep peroneal nerve

Deep in leg, then passes into foot and supplies 1st web space

Common peroneal most commonly injured resulting in paralysis of dorsiflexors and evertors = drop foot

Posterior tibial nerve is affected in tarsal tunnel syndrome (just posteror to anterior compartment

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tibial nerve and its branches

Medial and Lateral CalcanealMedial and Lateral Plantar

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Terminal branches of tibial nerve

medial plantar nervelarger

passes deep to abductor hallucis and runs between AbdH and FDB, lateral to medial plantar artery

supplies medial 3½ digits, and slightly wraps over onto dorsum

lateral plantar nervesmaller

deep to flexor retinaculum and AbdH and runs medial to lateral plantar artery between 1st and 2nd muscle layers

supplies lateral 1½ toes

Compression of this nerve is often mistaken for plantar fascitis

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Cutaneous Nerve Anatomy

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Saphenous

Superficial peroneal

Lateral cutaneous

Sural

saphenous nerveCutaneous branch of femoral nerve

serves posteromedial aspect of the leg

superficial peronealenters foot on dorsomediall aspect, anterior to medial malleolus

supplies skin along medial side of foot, sometimes as distal as the head of the first metatarsal

lateral cutaneous nerve of calfbranch of common peroneal

supplies skin over upper part of posterolateral aspect of the leg

sural nervebranch of tibial nerve

supplies posterolateral aspect of the leg and foot

enters foot posterior to lateral malleolus

supplies lateral border of foot and 5th digit

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cutaneous sensory innervation

Medial plantar

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Sural

Deep Peroneal

Superficial peronealSuperficial peroneal

Lateral PlantarCalcaneal branch of medial plantar

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cutaneous sensory innervation

Medial plantarLateral PlantarCalcaneal branch of medial plantarSuperficial peronealSuperficial peronealDeep peronealSuralSaphenous

©Medial View Lateral View

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Arterial Anatomy

Anterior Tibial Artery

Posterior Tibial ArteryPeroneal Artery

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Arterial Anatomy

Anterior view

Posterior view

posterior tibial artery

peroneal artery

dorsalis pedis artery

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Femoral

Dorsalis Pedis

Anterior Tibial

Post. Tibial

Lateral Plantar

Medial Plantar

Digital

Popliteal

Peroneal

Dorsalis pedis is palpated on the dorsum ot the foot between theEHL and EDL

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references

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references

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Grant’s Anatomy

Mulligan EP. Foot-Ankle Chapter in Physical Rehabilitation of the Injured Athlete. ed – Andrews, Harrelson, Wilk. Saunders, 2003.

Foot-Ankle Special Theme Issue. J OrthopSports Phys Ther 21:6, 1995.

Foot-Ankle Special Theme Issue. Phys Ther 68:12, 1986

Seibel MO. Foot Function: A Programmed Text. Lippincott Williams & Wilkins, 1988

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Thank you

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Reminder: TCJ and STJ flouroscopic and motin-axis video clips will be archived for download along with the recording files from this broadcast.