OrthoTx: Ankle

Myology Review

• Anterior compartment muscles are supplied by the deep fibular nerve
• Tibialis Anterior causes dorsiflexion and inversion
• Extensor Hallucis Longus causes dorsiflexion, inversion, and extension of the hallux
• Extensor Digitorum Longus causes dorsiflexion, eversion, and extension of digits 2-5
• Fibularis Tertius causes dorsiflexion and eversion
• Lateral compartment muscles are supplied by the superficial fibular nerve
• Fibularis longus causes plantar flexion and eversion
• Fibularis brevis causes plantar flexion and eversion
• Superficial posterior compartment muscles are supplied by the tibial nerve
• Gastrocnemius causes plantar flexion and knee flexion
• Soleus causes plantar flexion
• Plantaris causes plantar flexion and knee flexion
• Deep posterior compartment muscles are supplied by the tibial nerve
• Popliteus causes knee flexion and internal rotation of the tibia in an open chain, or external rotation of the femur in a closed chain
• Tibialis Posterior causes plantar flexion and inversion
• Flexor Digitorum Longus causes plantar flexion, inversion, and flexion of digits 2-5
• Flexor Hallucis Longus causes plantar flexion, inversion, and flexion of the hallux
• The tarsal tunnel contains the Tibialis Posterior, Flexor Digitorum Longus, Flexor Hallucis Longus, tibial artery/vein/nerve

Arthrology Review

• The foot and ankle are subdivided into the hindfoot, midfoot, and forefoot

Hindfoot Joints

• Includes the inferior tibiofibular, talocrural, and subtalar joints

Midfoot

• Contains articulations between the navicular, talus, cuboid, and calcaneus
• Specific details regarding talocalcaneonavicular, calcaneocuboid, cuboideonavicular, cuneonavicular, intercuneiform, and cuneocuboid joints are not required knowledge for the course

Forefoot

• It consists of the tarsometatarsal joints (Lisfranc's), functioning similarly to fingers
• Details about the intermetatarsal, metatarsophalangeal, and interphalangeal joints are not required for this course

Hindfoot Focus

• Has an emphasis on the closed pack position of each joint

Talocrural Joint

• Osteokinematics: Allows for 1 degree of freedom with plantar flexion and dorsiflexion
• Arthrokinematics: Convex talus articulates with concave tibia/fibula
• Resting Position: 10 degrees of plantar flexion between inversion and eversion
• Closed Packed Position: Extreme dorsiflexion
• Capsular Pattern of Restriction: Plantar flexion is more limited than dorsiflexion
• ROM & End Feel: Flexion/Extension is 0-135 degrees, with a firm end feel for all movements
• Commonly sprained ligaments: plantar flexion/dorsiflexion

Subtalar Joint

• Osteokinematics: Has 3 degrees of freedom with gliding (anterior-posterior) and rotation
• Arthrokinematics: Concave (superior/inferior) and convex (medial/lateral) articulations
• Resting Position: Midway between extreme ROM
• Closed Packed Position: Supination
• Capsular Pattern of Restriction: Varus is more limited than valgus
• ROM & End Feel: Flexion/Extension is 0-135 degrees
• Eversion and inversion occur here

Inferior Tibiofibular Joint

• Osteokinematics: Has 2 degrees of freedom including cranial/caudal and ventral/dorsal glide
• Arthrokinematics: Tibia is concave, while fibula is convex
• Resting Position: Plantar flexion
• Closed Packed Position: Extreme dorsiflexion
• Capsular Pattern of Restriction: Posterior to Anterior (P w/stress)
• ROM & End Feel: N/A, slight spreading (1-2mm) during plantar/dorsi flexion, Slt sup/inf glide of fib- axial load with dorsiflexion
• High ankle sprain/syndesmosis sprain occurs

Accessory Structures

• Review of ligaments, plantar fascia, and bursae

Lateral Collateral Ligament (LCL)

• Function: Prevents excess inversion
• MOI: Excess inversion, commonly on a plantar flexed ankle
• Supporting Muscle: Lateral compartment
• Anterior talofibular ligament (ATFL) is the most commonly sprained ligament that also prevents excess plantar flexion

Deltoid Ligament

• Function: Prevents excess eversion
• MOI: Excess eversion, could be on a dorsiflexed or plantar flexed ankle
• Supporting Muscles: Tibialis posterior and tibialis anterior

Interosseous Membrane

• Function: Prevents excess separation of the tibia and fibula
• MOI: Fixed ankle (footwear, tape) exposed to strong rotation force
• Supporting System: General strength

Anterior/Posterior Inferior Tibiofibular Ligament

• There is a normal spread of 1-2mm between these bones to allow talocrural movements

Plantar Calcaneonavicular Ligament (aka Spring Ligament)

• Function: Supports the medial arch of the foot
• MOI: Laxity leads to overpronated feet; traumatic injuries are not clinically relevant, more gradual
• Supporting Muscle: Intrinsic foot muscles and tibialis posterior

Plantar Fascia

• Dense, multilayered fascia
• Pain is most commonly felt starting at the calcaneus and spreading along the medial arch to the head of the metatarsal
• Pain can also occur on the lateral aspect of the calcaneus
• It is tensioned/lengthened via the windlass mechanism with extension or hyperextension of MTP joints

Bursae of the Foot

• Multiple bursae, but only 2 are clinically significant
• Superficial calcaneal/subcutaneous calcaneal bursa
• Deep/retrocalcaneal bursa

Biomechanics; Supination vs Pronation

Supination

• Components: Plantar flexion, inversion, and adduction

Pronation

• Components: Dorsiflexion, eversion, and abduction

Talocrural Joint During Supination and Pronation

• Supination = Plantar Flexion
• Pronation = Dorsiflexion

Subtalar Joint During Supination and Pronation

• Supination = Inversion
• Pronation = Eversion

Forefoot During Supination and Pronation

• Supination = Adduction
• Pronation = Abduction

Medial Longitudinal Arch During Supination and Pronation

• Supination = Increased arch height
• Pronation = Decreased arch height (flatter)

Functional Characteristics During Supination and Pronation

• Supination = Rigidity & Stability
• Pronation = Flexibility & Adaptability

Reason and Ground Surface During Supination and Pronation

• Supination = Stable base of support
• Pronation = Adapt to different ground surfaces

Gait Cycle Traditional Terminology During Supination and Pronation

• Supination = Heel strike & Toe-off
• Pronation = Foot flat & midstance

Gait Cycle RLA Terminology During Supination and Pronation

• Supination = Initial contact & Pre-swing
• Pronation = Load response & midstance

Gait Cycle

• Heel strike/Initial contact: Supination creates midtarsal rigidity which allows for controlled deceleration
• Midstance: Pronation creates midtarsal flexibility which allows for midtarsal to adapt to ground
• Toe-off/Pre-swing: Supination creates midtarsal rigidity which allows for midtarsal propulsion off the ground

Progressive Stabilisation

Progressive stabilisation is coordinated action at the talocrural, superior tibiofibular, and inferior tibiofibular joints

Initial Contact (Heel Strike)

• Ankle is in dorsiflexion and is very stable

Load Response (Foot Flat)

• Body moves forward, and ankle moves into plantar flexion
• Body continues moving forward with increasing dorsiflexion
• Tibia and fibula move forward
• Talus spreads the inferior tib-fib joint between 1-2mm
• As the fibula moves superiorly, it is checked with resistance by the interosseous membrane, pulling the membrane taut

Midstance

• The leg is stabilized
• Tension in the interosseous membrane stabilizes the lower leg with the superior and inferior tibiofibular joints
• Midstance is the most challenging phase of gait in high ankle sprains or syndesmosis injuries

Interosseous Membrane Function

• The important function is to stabilize the tibiofibular joints to create a stable leg to allow the foot to become flexible and adaptable during midstance

Foot Alignment and Arches

Triangular Stance

• Humans stand on a triangle formed by MT1 to MT5 to Calcaneus
• The arches of the foot are within this triangle

Arches of the Foot

• The foot has three: medial longitudinal, lateral longitudinal, and transverse arches

Medial Longitudinal Arch

• Characteristics: Adjustable and mobile
• Stability (Muscle): Tibialis anterior and tibialis posterior
• Stability (Ligament): Plantar calcaneonavicular ligament (Spring ligament)
• Mobility: Can twist in pronation/supination

Lateral Longitudinal Arch

• Characteristics: More stable than medial and less adjustable
• Stability (Muscle): Primarily by the lateral compartment
• Stability (Ligament): Short and long plantar ligaments
• The Keystone of the arch: Cuboid

Transverse Arch

• Runs across the tarsals and metatarsals
• Stabilized by: Plantar fascia, tibialis posterior, and the stirrup

Gait Cycle

Gait Cycle Definition

• The time between two consecutive initial contacts of the same part of the same foot, i.e. right heel strike to right heel strike
• Includes both stance and swing phases
• Equivalent to stride length, the distance covered in one gait cycle

A Step

• It is half of a gait cycle
• From right heel strike to left heel strike

Gait Cycle Phases

• Swing phase = 35-40% of the gait cycle
• Stance phase = 60-65% of the gait cycle

Naming Convention

• There are two sets of nomenclature for gait, it is important to be able to recognize all 8 phases with either
• Traditional and Ranchos Los Amigos terminology

Muscle Stability

• In walking gait, as the foot lands at initial contact, hip extensors undergo eccentric activation to slow down arc through flexion
• Dorsiflexors are active at initial contact, controlling the foot rolling from heel to midfoot
• Lack of dorsiflexion leads to a slapfoot

Load Response

• Dominated by the deep posterior compartment, especially tibialis posterior
• Foot goes from supinated to pronated, flattening the medial arch and adapting the foot to the ground
• Tibialis Posterior controls this
• Knee extensors are active, switching from eccentric to concentric activity

Midstance

• Strong isometric gluteus medius activation stabilizes single leg stance
• Eccentric activity occurs at the ankle of plantar flexors
• Lack of gluteus medius leads to a Trendelenburg gait or a lurch gait

Terminal Stance

• Foot begins to resupinate and plantar flex
• Supination creates a rigid foot to propel the body's weight through plantar flexors

Pre-Swing

• Hip flexors activate concentrically to bring the limb from extension into flexion

Initial Swing

• Hip flexors and ankle dorsiflexors needs activation
• Lack of dorsiflexion leads to a steppage gait

Terminal Swing

• Knee extensors activate to extend the knee
• Hip extensors are active eccentrically to slow the limb and prepare for initial contact

Gait Abnormalities

(1) Weak hip extensors = backward lurch gait (2) Weak dorsiflexors = slapfoot (3) Weak hip abductors = Trendelenburg gait or Abductor Lurch gait (4) Midstance is highly provocative for high ankle sprains because the tibia moves forward over the talus, the inferior tib-fib joint spreads, which is checked by the syndesmotic ligaments that are injured in a high ankle sprain (5) Weak dorsiflexors here = steppage gait

Foot Abnormalities

Hindfoot Varus

• Lateral rotation (inversion) of the calcaneus
• Presents as pes cavus/supinated foot and is rigid/less adaptable
• Results in genu varum, leading to forefoot valgus

Hindfoot Valgus

• Medial rotation (eversion) of the calcaneus
• Presents as pes planus/pronated foot and is mobile/less rigid
• Results in genu valgum, leading to forefoot varus

Forefoot Valgus

• Associated with hindfoot varus
• Leads to pes cavus
• Predisposes to lateral ankle sprains, ITB friction syndrome, and plantar fasciitis

Forefoot Varus

• Associated with hindfoot valgus
• Leads to pes planus
• Predisposes to patellofemoral syndrome, shin splints, and plantar fasciitis

Pes Cavus

• Hollow or rigid foot with increased longitudinal arches
• Less common and often not problematic
• A foot that is less adept at adapting to the ground

Pes Planus

• Flat or mobile feet; common and often not problematic
• It is a decrease in the medial longitudinal arch
• Causes include congenital factors, trauma, muscle weakness, ligament laxity, postural issues, and shortened muscles
• Similar to scoliosis, can be rigid (structural) or flexible (functional)
• Differentiate by observing a flatfoot while standing, asking the patient to stand on tiptoe; and observing the effect on the arch; when the arch appears it is flexible/seldom needs treatment as opposed to remaining flat/rigid

Hallux Valgus

• Common and often leads to a bunion formation
• Bunion is a bony spur or bony exostosis
• Wolff’s law refers to irritation leading to the body laying down more tissue (bunions also occur at the styloid process of the 5th metatarsal; these are called Tailor’s bunions)

Gait Abnormalities

Antalgic Gait

• An altered gait due to pain as the body tries to avoid painful actions
• The affected leg stance phase is shorter and the unaffected leg swing phase is shorter

Hemiplegic Gait

• Hemiparetic gait, where the affected leg is swung out in circumduction with the affected upper limb carried across the trunk for balance

Glute Max Gait

• Weakness in the gluteus maximus muscle results in decreased hip extension strength
• To compensate, the torso is thrust posteriorly on initial contact, creating a backwards lurch of the trunk

Trendelenburg Gait

• Gluteus medius weakness causes the unaffected leg (swing leg) to dip towards the affected side (stance leg)

Abductor Lurch Gait

• Glute medius weakness causes the torso to lurch towards the weak side to balance the center of mass

Scissor Gait

• Results from spastic paralysis of hip adductors where feet cross in front of one another like a pair of scissors walking

Steppage Gait

• Weak or paralyzed dorsiflexors resulting in dropfoot (may be due to L2-L4 lesion)
• It is where the person has to elevate the knee and flex the hip to allow the toes to clear the ground at initial swing

Foot Slap

• Due to weak or paralyzed dorsiflexors but occurs at initial contact
• The foot slaps the ground because dorsiflexors cannot control foot motion

Pathologies

Acute Compartment Syndrome

• It is a medical emergency
• Due to massive trauma or serious infection
• Most commonly affects the anterior compartment but can involve all compartments
• Characterized by severe and persistent pain
• Bleeding, swelling, taut/shiny/hot skin
• Paresthesia and motor loss occur
• Requires emergency surgery (fasciotomy)

Overuse Syndromes

The following are overuse syndromes of the leg, ankle, and foot:

• Chronic Compartment Syndrome
• Tibial stress fractures
• Periostitis
• Achilles Tendonitis
• Tib Post tendinitis
• Plantar Fasciitis
• They share a lot in common, which will be discussed now, following, focus on the key info to distinguish one from the other

Causes of Overuse

• Poor training or poor programming (training load)
• New activity or sudden increase in activity
• Footwear and equipment
• Poor recovery habits/overtraining
• Biomechanical or postural abnormalities as well as poor muscle function (tone, TrPs) or poor joint function (mobility) will all predispose one to an overuse condition
• These are particularly prominent in the lower leg that has strong, distinct compartments prone to adhesions

Shin Splints

• Is a catch all phrase for a number of different conditions affecting the lower leg and may involve the tibia and the muscles of the lower leg
• Discussed individually, these conditions are compartment syndrome, tibial stress fractures, periostitis

Chronic Compartment Syndrome

• Pain increases with activity and decreases with rest
• Can occur in any compartment
• Commonly in the deep posterior and anterior compartments
• Paresthesia during exercise

Chronic Compartment Syndrome - Anterior

• Pain presents at the anterior/lateral region of the tibia

Chronic Compartment Syndrome - Posterior

• Pain and discomfort along the post/medial border of the tibia
• Swelling and palpable tenderness along the tendons of TP, FDL, and FHL
• MMT reveals weak plantar flexion and inversion
• Excessive foot pronation, poor control of medial longitudinal arch

Tibial Stress Fractures

• Repeated impact to the tibia or repeated muscle force strain to the tibia
• Gradual onset, then pain progresses
• Pain with initial activity is relieved by rest
• Progresses to long duration of pain (hours) with possible nocturnal pain (indicative of bony involvement)

Periostitis

• MTSS; Medial Tibial Stress Syndrome, Tenoperiostitis, Soleus Syndrome
• Inflammation of the periosteum near the origin of tibialis posterior and soleus on the medial tibial border
• Exercise-induced microtears to periosteum caused by excessive muscle contraction
• May progress to a stress fracture
• Pain exists at the beginning of exercise, decreases after a warm-up, and returns at the end of exercise
• As pain progresses, becomes felt throughout exercise and during ADLs
• Pain during the pre-swing phase of gait

Calcaneal Tendonitis

• Review of what the grades of tendonitis are
• Review of what assessments provoke (give a positive) tendonitis
• Causes can be:
  • forced dorsiflexion (eccentric contraction & excessive pronation), such as landing from jumping
  • Poor flexibility or fatigued muscle transfer load to tendon, which causes overloads

Tibialis Posterior Tendonitis

• Plays an important postural function in load response and midstance
• Predisposed by change to running terrain, poor flexibility, poor footwear, and alignment abnormalities
• Pain is along the medial border of the tibia, middle/distal 1/3, especially apparent with loading response in gait
• Exhibits weak and painful plantar flexion and inversion
• Pain is worse with load response in gait
• May predispose to tarsal tunnel syndrome

Plantar Fasciitis

• Common, may lead to deposition of bone and bone spur on medial calcaneus
• Hypertonic gastrocs/soleus
• Weak intrinsic foot muscles may predispose
• Improper footwear
• Weight gain or pregnancy
• Foot abnormalities predispose
• Pain worsens with activity, especially pre-swing/toe-off, possible at night
• Hallmark = first few steps after non-weight bearing

Inversion Sprain

• MOI involves plantar flexion and inversion
• Commonly affects the Anterior Talofibular Ligament
• Ligaments that are affected include the calcaneofibular and calcaneocuboid ligaments
• Stimulation of the peroneals following an inversion sprain is imperative because it can cause overstretch and inhibition to the lateral compartment

Eversion Sprain

• MOI has excess eversion and can be with plantar or dorsiflexion
• It is a rarer injury
• It can affect the deltoid ligament (Ant and Post Tibiotalar)
• Stimulate the tibialis posterior following the injury because it can cause causes overstretch and inhibition to the deep posterior compartment

High Ankle Sprain

• Also called a Syndesmosis Sprain
• Affects the Anterior and Posterior tibiofibular ligaments
• May affect the interosseous membrane
• Occurs above the talocrural joint at the distal/inferior tibiofibular joint
• MOI involved foot rotation aganist a fixed lower leg
• It is a common basketball or hockey injury due to footwear locking the talocrural and subtalar joints to have rotational forces on the distal tib fib joint
• It presents as dull or sharp pain in the anterior/lateral region of the lower leg, proximal to the ankle, and worsens with twisting/midstance
• High ankle sprains are identified only following unsucessful inversion/eversion treatment

Pes Planus Foot Abnormality

• It is due to weakness of intrinsic foot muscles or tibialis posterior
• Occurs with laxity in plantar calcaneonavicular lig (Spring lig)
• Associate with hypertoned triceps surae, decreased dorsiflexion

Pes Cavus Foot Abnormality

• Indicated approach to keep the tissue as healthy as possible with lower leg and foot treatment

Peripheral Nervous System

• Conditions such as Morton’s neuroma and tarsal tunnel syndrome exist
• Requires referral to PNS Tx class

Home Care: Principles

• Programs must not exacerbate pain/inflammation
• Exercise should be gradual and progressive
• Commencement of exercise should occur as early as possible, provided there is no inflammation

Considerations for Choosing Exercises

• Loaded exercises should be performed in mid-range
• Range should be increased in unweighted settings
• It is recommended not to load at the end range
• Exercises should progress as isometric before eccentric before concentric before plyometric
• Gravity should be removed first (e.g. theraband clamshells) before adding it (e.g. squat)
• Progression is best with bilateral exercise first, then unilateral next

Program Challenge

• Post-exercise discomfort should not last longer than 2 hours in the acute/subacute stage
• Post-exercise discomfort should not last longer than 4 hours in the chronic stage
• There should be no need for pain medication to control discomfort after activity or exercise
• Do not continue if there is pain @ rest, extreme fatigue, and rebound muscle spasm (not DOMS)

Specific Ideas

• Stretches: Teach a hold-relax with agonist contract to triceps surae
• Standing lunge to increase dorsiflexion
• Self-Massage: Ice bottle for plantar fasciitis and lacrosse ball for plantar fascia to address posterior superficial line tightness
• Strengthening: Single-leg calf raises, intrinsic foot muscles with towel, tibialis posterior activation with towel, lateral compartment activation, Hallux curls, Theraband toe control exercises (hallux only; digits 2-5 only)
• Postural and Orthotics: Only recommend a referral if you can provide a personal reference and give toe spacers to the affected foot
• Hydro: Conduct contrast foot baths - or you can progress straight to cold water walking if tolerated
• Balance: Maintain single leg stance on a firm surface, and gradually progress the exercise til eyes are closed; a perturbed surface (such as that used in surfing) should only be used if that surface it routinely used
• Rigid Taping: Great way to used for ankle support and stability; common application in sports and requires use of old-school rigid tape rather than K-tape or kinesio tapes