Clinical Anatomy, Kinesiology, and Evaluation of the Ankle and Foot

Course Overview: Ankle and Foot Module

• Lecture 1: Self-review of anatomy and kinesiology, introduction to evaluation, and special testing.

• Lab 1: Joint evaluation.

• Lecture 2: Common pathologies (practice patterns).

• Lab 2: Manual interventions.

• Lecture 3: Common pathologies (practice patterns).

• Lab 3: Therapeutic exercise and treatment interventions.

• Lecture 4: Common pathologies (practice patterns).

• Lecture 5: Case study discussions.

Essential Professional Knowledge for Physical Therapists

• Foundational Knowledge: A successful PT must possess deep knowledge in Anatomy and Physiology.

• Communication Skills: Effective use of "Mouth & Ears" (listening to and talking with the patient).

• Clinical Considerations:

  • Tissue Identification: Knowledge of the specific tissue(s) type injured or affected.

  • Injury Timing: Understanding when the injury occurred (acute, sub-acute, chronic).

  • Injury Mechanism: Understanding how the injury happened.

  • Tissue Stress: Knowledge of the current "physical stress" state of the tissue.

• Patient Context (Social Determinants of Health):

  • Current health status.

  • Co-morbidities.

  • Psycho-social status.

  • Environmental influencers.

• Technical Proficiency:

  • Knowledge of all evaluation components.

  • Skill in interpreting evaluation findings to determine intervention options.

Purpose and Function of the Ankle and Foot

• Weight Support and Distribution: Supporting body weight, shock absorption, and adapting to various ground structures and forces.

• Stability: Providing a base of support and functioning as a rigid lever for propulsion.

• Mobility: Enabling locomotion and facilitating torque conversion during the gait cycle.

Anatomical Anatomy of the Leg and Ankle

• Bony Presentation:

  • Tibial Torsion: The natural rotation of the tibia.

  • Fibula: The lateral malleolus is seated distal and posterior relative to the tibia.

  • The Mortise: Formed by the medial malleolus of the tibia and the lateral malleolus of the fibula, which accepts the talus.

Musculature and Innervation

Posterior Compartment

• Gastrocnemius:

  • Heads: Medial and Lateral.

  • Innervation: Tibial Nerve ($L5$, $S1$, $S2$).

• Soleus:

  • Innervation: Tibial Nerve ($S1$, $S2$).

• Deep Posterior Muscles (Tibial Nerve):

  • Tibialis Posterior: Innervation ($L4$, $L5$, $S1$).

  • Flexor Digitorum Longus: Innervation ($L5$, $S1$, $S2$).

  • Flexor Hallucis Longus: Innervation ($S2$, $S3$).

Lateral Compartment

• Fibularis (Peroneus) Longus and Brevis:

  • Innervation: Superficial Fibular Nerve ($L5-S1$).

  • Insertion Notes: Fibularis longus passes under the foot to the medial cuneiform and metatarsal I; Fibularis brevis inserts on the base of the $5^{th}$ metatarsal.

Anterior Compartment

• Muscles (Deep Fibular Nerve):

  • Tibialis Anterior: Innervation ($L4-L5$).

  • Extensor Digitorum Longus: Innervation ($L5$, $S1$).

  • Extensor Hallucis Longus: Innervation ($L5$, $S1$).

  • Peroneus (Fibularis) Tertius.

Plantar Foot Musculature (Superficial to Deep)

• Layer 1:

  • Abductor Hallucis.

  • Flexor Digitorum Brevis.

  • Abductor Digiti Minimi.

• Layer 2:

  • Quadratus Plantae (Flexor Digitorum Accessorius).

  • Lumbricals $2-5$ ($x4$).

• Layer 3:

  • Flexor Hallucis Brevis.

  • Adductor Hallucis.

  • Flexor Digiti Minimi Brevis.

  • (Opponens Digiti Minimi).

• Layer 4:

  • Dorsal Interossei ($x4$).

  • Plantar Interossei ($x3$).

Joint Classifications and Structures

• The Foot: Comprised of 26 bones (excluding tibia/fibula) consisting of 7 tarsals, 5 metatarsals (MT), and phalanges, totaling 25 joint components.

• Key Joints:

  • Distal Tibio-Fibular Joint: A fibrous joint (syndesmosis). It features a large lateral talar facet allowing translation.

  • Ankle (Talocrural) Joint: A hinge joint. The articular surface is wide anteriorly and narrow posteriorly.

  • Subtalar (Talocalcaneal) Joint: A modified multi-axial joint.

  • Transverse Tarsal (Mid-Tarsal) Joint: Functional unit composed of the Talocalcanealnavicular, Calcanealcuboid, and Talonavicular articulations.

  • Metatarsal Phalangeal (MTP): Synovial/condyloid (ellipsoid) joints.

  • Interphalangeal (IP) Joints.

• Superior Tibio-Fibular Joint: A planar/synovial joint with a fibrous capsule whose function is closely related to the ankle joint.

• Arches:

  • Medial Longitudinal Arch.

  • Lateral Longitudinal Arch.

  • Transverse Arch.

Ligamentous Support

• Medial (Deltoid Ligament): Extremely strong. Prevents excessive eversion. Includes:

  • Tibionavicular.

  • Tibiocalcaneal.

  • Posterior Tibio-talar.

  • Anterior Tibio-talar.

• Lateral Ligaments: Prevent excessive inversion. Includes:

  • Anterior Talo-Fibular (ATF).

  • Posterior Talo-Fibular (PTF).

  • Calcaneofibular.

• Distal Tib-Fib Ligaments: Anterior and posterior tibiofibular and the interosseous membrane.

• Mid-Tarsal Ligaments:

  • Plantar Calcaneonavicular (Spring ligament).

  • Bifurcate ligament.

  • Long and short plantar ligaments.

Compartments and Retinacula

• Tarsal Tunnel (Medial): Contains Tibialis Posterior tendon, Flexor Digitorum Longus tendon, Posterior Tibial artery (pulse found midway between heel and medial malleolus), Tibial nerve, and Flexor Hallucis Longus tendon. Held by Flexor retinaculum.

• Lateral Compartment: Contains tendons of Fibularis Longus and Brevis. Held by Superior and Inferior fibular retinacula.

• Anterior Compartment: Contains Tibialis Anterior, Extensor Hallucis Longus, Extensor Digitorum Longus, and Fibularis Tertius. Holds the Anterior Tibial artery (becoming Dorsalis Pedis artery) under the Superior and Inferior extensor retinacula.

• Posterior Compartment: Contains Gastrocnemius, Soleus, and Plantaris, leading to the Calcaneal (Achilles) tendon.

Osteokinematics of the Ankle and Foot

• Tri-Planar Motion: While often described as moving in the sagittal plane, ankle motion occurs in three cardinal planes:

  • Sagittal Plane: Dorsiflexion (DF) and Plantarflexion (PF).

  • Frontal Plane: Eversion and Inversion.

  • Transverse Plane: Abduction and Adduction (rotation).

• Normal Range of Motion (ROM):

  • Dorsiflexion: $0-20^{\circ}$.

  • Plantarflexion: $0-50^{\circ}$.

  • Inversion: $0-30^{\circ}$.

  • Eversion: $0-20^{\circ}$.

• Coupled Motions (Talocrural):

  • Dorsiflexion is coupled with Eversion and Abduction.

  • Plantarflexion is coupled with Inversion and Adduction.

• Closed Packed Position: Maximum Dorsiflexion (due to the wider anterior portion of the talus fitting into the mortise).

Arthrokinematics

Tibio-Fibular Joints

• Superior Tibio-fibular:

  • Dorsiflexion: Superior/Posterior glide.

  • Plantarflexion: Inferior/Anterior glide.

• Distal Tibio-fibular:

  • Dorsiflexion: Superior/Anterior glide; the mortise widens (fibular separation) to accommodate the wide anterior talus.

  • Plantarflexion: Inferior/Posterior glide.

Ankle Joint (Talocrural)

• Open Chain (Convex Talus on Concave Tibia): Rule states roll is same direction as motion, glide is opposite.

  • Dorsiflexion: Talus rolls anteriorly, glides posteriorly.

  • Plantarflexion: Talus rolls posteriorly, glides anteriorly.

• Closed Chain (Concave Tibia on Convex Talus): Rule states glide and roll are in the same direction.

  • Dorsiflexion: Tibia rolls and glides anteriorly.

  • Plantarflexion: Tibia rolls and glides posteriorly.

Subtalar and Mid-Tarsal Osteokinematics

• Definitions:

  • Supination: Composite motion of Inversion (frontal), Adduction (transverse), and Plantarflexion (sagittal).

  • Pronation: Composite motion of Eversion (frontal), Abduction (transverse), and Dorsiflexion (sagittal).

• Open Chain (Calcaneus on Talus):

  • Inversion: $0-20^{\circ}$.

  • Eversion: $0-10^{\circ}$.

• Closed Chain (Talus on stable Calcaneus):

  • Supinated (Heel Strike): Calcaneal inversion + Talar abduction and dorsiflexion. Results in lateral tibial rotation and the creation of a "rigid lever" (raising the arch).

  • Pronated (Mid-stance): Calcaneal eversion + Talar adduction and plantarflexion. Results in medial tibial rotation and a "flexible lever" (lowering the arch) for force dissipation.

• Mid-Tarsal Function: Links hindfoot to forefoot; allows forefoot to stay on the ground regardless of hindfoot position.

  • Forefoot Inversion: $0-20^{\circ}$.

  • Forefoot Eversion: $0-10^{\circ}$.

Tarsometatarsal (TMT) and MTP Joints

• TMT Joint Stability:

  • $1^{st}$ and $5^{th}$ MT: Most mobile.

  • $2^{nd}$ MT: Most stable (mortised between cuneiforms).

• Supination/Pronation Twists: Compensation mechanisms of the forefoot based on hindfoot position.

  • Supination Twist: $1^{st}/2^{nd}$ rays Dorsiflex; $4^{th}/5^{th}$ rays Plantarflex.

  • Pronation Twist: $1^{st}/2^{nd}$ rays Plantarflex; $4^{th}/5^{th}$ rays Dorsiflex.

• MTP Joints: Function to provide extension mobility for terminal stance and stabilize the foot during push-off.

Functional Support and Passive Insufficiency

• Medial Longitudinal Arch Soft Tissue Support: Plantar fascia, plantar ligaments, spring ligament.

• Windlass Mechanism: Arch is supported/raised with the extension of the digits (primarily the great toe).

• Arch Dynamic Support (Muscle Contribution): Tibialis Posterior and Peroneus Longus have the highest research-indicated contribution.

• Passive Insufficiency: Defined as the inability of a multi-joint muscle (like the gastrocnemius) to lengthen and allow full ROM at all joints it crosses. If the knee is extended, the gastrocnemius is stretched, potentially limiting ankle dorsiflexion.

Ankle Evaluation and Specific Testing

Screening and Observation

• Initial evaluation includes History, Review of Systems, and screening all LE joints (including lumbar spine).

• Physical check of Posture/Appearance (Tibial torsion, foot position), Circulation (pulses), and Sensation (dermatomes/peripheral nerves).

Special Tests: Muscle Length & Structure

• Ottawa Ankle Rules: Used to determine the need for X-rays. Clinical findings: Tenderness at posterior edge/tip ($6\,cm$) of malleoli, tenderness at base of $5^{th}$ MT, tenderness at navicular, or inability to bear weight.

• Gastrocnemius vs. Soleus Length: Assess DF with knee extended (Gastroc) vs knee flexed (Soleus). Normal DF in lunge position is $30-40^{\circ}$.

• Subtalar Neutral: Determines rearfoot/forefoot position (e.g., Varus).

• Feiss Line / Navicular Drop: Measures medial arch height. Positive for flatfoot if drop is > 6-8\,mm from neutral to relaxed stance.

• Relaxed Calcaneal Stance: Measures calcaneal eversion; excess is defined as > 6^{\circ}.

• Thompson Test: Squeeze calf to check for PF response. Absence indicates Achilles rupture (Sens $96\%$, Spec $93\%$).

• Figure 8: Tape measurement to quantify ankle edema.

Special Tests: Mechanical Stress

• Anterior Drawer Test: Diagnose ATFL instability (Sens $86\%$, Spec $74\%$).

• Tilt Test: Diagnose Calcaneofibular (Inversion) or Deltoid (Eversion) instability.

• Kleiger (External Rotation) Test: Diagnose syndesmosis (high ankle) injury or deltoid ligament injury.

• Tap (Percussion) and Squeeze Tests: Used to screen for fractures of the tibia, fibula, or syndesmosis injury.

• Neuroma Test: Squeeze metatarsal heads together to detect interdigital neuroma.

• Windlass Test: Extend $1^{st}$ MTP to detect plantar fascia pain (Spec $100\%$).

Vascular Assessment

• Buerger’s Test: Patient supine, leg raised to $45^{\circ}$ until pale, then sat up. If leg turns blue then red, it indicates hyperactive hyperemia (Sens $100\%$).

• Ankle-Brachial Index (ABI).

Functional Outcome Measures

• Lower Extremity Functional Scale (LEFS): Max score $80$. Minimum detectable change is $9$ points.

• Single Leg Stance / Heel Raise.

• Star Excursion Balance Test / Y-Balance Test.

Ankle Pathologies by Practice Patterns

• 4B (Impaired Posture): Deformities, Tibial Torsion.

• 4D (Connective Tissue Dysfunction): Arthritis (RA, OA, Gout), Ligament sprains/tears, Hallux dysfunction, Os Trigonum, Turf Toe, Cuboid Syndrome.

• 4E (Localized Inflammation): Fasciitis, Tendinopathy, Shin Splints (Medial Stress Syndrome), Bursitis, Metatarsalgia, Sesamoiditis.

• 4G (Fracture): Stress fractures, Pilon, Talar, Malleolar, Lisfranc, and $5^{th}$ MT fractures.

• 4H/4I (Surgical): Joint Arthroplasty, ORIF, Ligament/Tendon repairs, Arthrodesis.

• 5F (Peripheral Nerve): Tarsal Tunnel Syndrome, Neuroma, Peripheral Neuropathy.