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Muscles of the Foot and Ankle

Dorsal Venous arch:
Gives rise to saphenous vein medially and
gives rise to lesser saphenous vein laterally.

The saphenous vein is located in front of the medial malleoli.
Deep Fascia of the dorsum of the Foot

Deep Fascia of the dorsum of the foot is continuous with the fascia cruris via extensor retinacula.
Deep fascia blends in with the plantar fascia medially and laterally.
Deep fascia is the roof of the first fascial space of the dorsum of the foot.
Three layers on dorsum of the foot.

First layer of the dorsum of the foot

First layer lies between the superficial part of the dorsalis pedis.
Contains AT, EHL, EDL and Peroneus tertius.
All these tendons are in synovial sheaths which are three in number.
AT and EHL have seperate tendon sheaths and EDL & Peroneus Tertius have their own.

click above for full image.

click above for full image.

click above for full image.

2nd Layer of the dorsum of the foot

Contains one intrinsic muscle of the foot Extensor digitorum brevis and fascial coverings.
Fascial coverings are the deep layer of the dorsalis pedis fascia.
Extensor digitorum Brevis from the anterior aspect of the dorsum of the calcaneus divides into four tendons and passes into medial 4 toes.
* There is no extensor digitorum brevis on the 5th toe.


Extensor Digitorum Brevis:

Origin: Superior aspect of the calcaneus anterior to the sinus tarsai, partially from the interosseous talocalcaneal ligament.
Insertion: splits into 4 slips, most medial one the EHB inserts on the dorsal aspect of the base of the proximal phalanx of the hallux, other 4 slips on the lateral side of the EDL (extensor digitorum longus) of 2nd, 3rd and 4th toes - contributes to extensor expansion.
Action: Extend phalanges of 2nd/3rd/4th toes, helps with MPJ (metatarsophalangeal joints) extension.
Nerve: Deep peroneal nerve, lateral branch; dorsalis pedis artery via lateral branch.
Layers of the Foot:
 
 
Compartments of the plantar surface of the foot:

Dorsally there are 3 compartments.
Plantarly there are 4 compartments.
The dorsal and plantar compartments are seperated by:
dorsal interossei, aponeurosis and metatarsals.

Medial compartments: abd. hallucis, FHB, FHL (flexor hallucis brevis and flexor hallucis longus)

Central Compartment: Flexor digitorum brevis, flexor accessorius, adductor hallucis.

Lateral compartment: Abductor digiti minimi, flexor digiti minimi brevis.

Interosseus compartment.

First Layer Muscles:
Abductor hallucis, flexor digitorum brevis and abductor digiti minimi.

Abudctor Hallucis:
Origin: medial process of calcaneal tuberosity, flexor retinaculum, medial intermuscular septum.

Insertion: medial plantar aspect of the proximal phalanx of the hallux.

Action: abducts and plantarflexes toes.

Nerve: medial plantar nerve and artery.

Flexor Digitorum Brevis:
Origin: medial process of the calcaneal tuberosity, medial and lateral intermuscular septa.

Insertion: middle phalanges of the toes (except for the hallux)

Action: Flexes toes at PIPJ and MPJ

Nerve: medial plantar artery and nerve.



Abductor digiti minimi:

Origin: Lateral process of calcaneal tuberosity.
Insertion: lateral plantar aspect of the proximal phalange of the 5th toe.
Action: Abduct and flex fifth toe.
Nerve: Lateral plantar nerve and artery.

 

To be continued...

Anatomy of Foot and Ankle

Tibial Tuberosity:
 Important for tendons and a useful surface landmark.


Head of Fibula:
Easily palpated because of the subcutaneous on the posterolateral aspect of the knee.
Division of the common peroneal nerve occurs here.

Lateral Malleolus:
 
Medial Malleolus:
 
Calcaneus:
 
Styloid Process:
can be palpated in the middle of the lateral border of the foot.

Ankle Joint:
Felt between the tendons as a depression at level 1.5cm superior to the tip of the medial malleolus.

Navicular:
Visible/palpable. Anteroinferior to the medial malleolus.

Arterial Supply

Anterior tibial Artery: Supplies the anterior compartment muscles of the leg.
Posterior tibial artery: supplies the posterior compartment muscles of the leg.
Peroneal artery: supplies the lateral compartment muscles of the leg.

The femoral artery becomes the popliteal artery divides into posterior, anterior tibial and peroneal arteries.

 
Pedal Pulses:
 
Dorsalis Pedis Pulse: 1 finger lateral to the exntesor hallucis longus.
Posterior tibial pulse: between medial malleolus and the cancaneal tendon.

Venous Supply:
Nerve Supply:
Tibial Nerve - supplies posterior compartment muscles.
Deep peroneal Nerve - supplies anterior compartment muscles.
Superficial peroneal Nerve - innervates lateral compartment muscles.
Tibial Nerve bifurcates at the level of the medial malleolus.

MUSCLES:

Anterior Group Muscles:

Actions: Dorsiflexes foot (tibialis anterior also inverts, Peroneus tertius also everts, Extensor digitorum longus & Extensor hallucis longus extends the toes)
Blood Supply: Anterior tibialis Artery
Innervation: Deep peroneal Nerve

Lateral Group:

Actions: Everts foot (weak plantarflexion)
Blood Supply; Peroneal Artery
Nerve Innervation: Superficial peroneal Nerve.

Posterior Group:
Actions: Plantarflex (weak inversion) foot.
Arteries: Post tibial Artery
Nerve: tibial nerve.
The posterios muscles include the achilies (gastric and soleus), superficial (gastric and soleus), deep (flexor hallucis digitorum/tibialis posterior), deltoid ligament (Connects tibia, calcaneus and talus)

Medial Ligaments:
Medial/deltoid ligament is strong, it attaches to the medial malleolus and base to the tarsus. Divided into 4 parts: tibionavicular, tibiocalcaneal, posterior tibiotalar, anterior tibiotalar. 

Lateral Ligaments:
3 Ligaments that attach lateral malleolus to the tarsus:
Anterior talofibular, posterior talofibular and calcaneofibular.



Analysis of Movement

General Systems for observing movement: subjective or objective


Subjective Analysis - Spectator Analysis

Example analysis: good shot, bad pass, stick the landing, you missed etc.
* always have negative comments in between good comments.
* good comments > negative comments.


Subjective Analysis - Pre-Analysis

- Skill level ( different systems/techniques used for different set of groups )
- The person's aspirations (If the player is here for fun or wants to achieve something)


Subjectvie Analysis - System

System: Preparation, observation, evaluation/diagnosis, intervention, observation (cycle starts again).

Mechanical Models

Mechanical Models of a performance is required to decide on:
- Critical Variables in performance (eg. knee flexion in tennis serving)
- Range of acceptability (eg 90 degree knee flexion)
* Critical variables refer to the variables that have a large role in performance.
* Range of acceptability maybe 90 degrees + or - 10 degrees to give an acceptable range of angle.
* Range of acceptability varies with person's age.

Critical Variables in playing baseball
- maximal external rotation of the shoulder.

Mechanical Model Example:

Mechanical Model for High Jump:

 
Height - refers to the measurement you would use for the performance.
Boxes below - factors that would affect the height of the high jump (measurement).

Running Mechanical Model:
Subjective Analysis - Observation:

Phasic Analysis (eg. tennis): Observations of preliminary movements, backswing, forwardswing (impact, release), Follow-through.

Body Area Analysis:
Head & Trunk - Line of sight, shoulder and pelvis alignment/rotations, position of head to COG.

Upper Limb - Position of limbs to the trunk, grip, elbow angle at impact/release, shoulder abduction angle.

Lower Limb - Knee flexion, alignment of feet and hips.

After observing with critical Variables in mind:

- Rank errors (cause and effect), remember the timing of events.


Objective Analysis: Video, Force, EMG

Video; Standard digital and High Speed.
Force: Force platforms to measure pressure on foot etc.
Electromyography: Measures muscle contraction rate and force.

Outcomes:

[SSEH2280] Lecture 2 - Linear Kinematics

Linear Kinematics

Linear Kinematics: description of motion along a line.
- Rectilinear (Pure Straight Line) or Curvilinear (straight lines on a curve)
- Describe and use terms such as "displacement, velocity and acceleration.

Basic Revision

Scalars: fully described by a magnitude/numerical value (has no direction)
Vectors: described by both magnitude and direction (has direction)
Eg:
 

What is Displacement?
Difference between distance and displacement.
Distance: Distance refers to how much ground is coered.
Displacement: Displacement refers to how far out of place you are. Final location minus the initial location. (eg. It would be 0 if you ran in a circular path and returned to the same location as you started)

Linear Velocity

Time rate of change of displacement (m/s = m.s.-1)
Speed: How fast and object is moving.
Velocity: The rate at which an object changes position.
Sometimes the term speed and velocity is interchangeable.
Speed is a scalar while velocity is a vector.
V = Change of displacement divided by time.

Instantaneous Velocity
Absolute change of velocity between the smallest time space attainable (i.e. 0.2 secs)
The velocity at any given instant of time (slope) of the velocity curve.


Linear Acceleration

Equations:

a = change in v divided by t
a = V2 - V1 / t
a = Vf - Vi / t

No Change in velocity = no acceleration.

Relationship between Displacement, Velocity and Acceleration.

Displacement determines velocity and velocity in turn determines acceleration.
Maximum velocity means that there is 0 acceleration because it shows that velocity will not increase anymore.
The Acceleration curve above 0 means acceleration is still occurring whilst an acceleration curve below 0 means that deceleration is in place.

Quantifying Linear Motion

3 Equations (Vertical Components):
Vf = Vi + at
V^2 f = Vi^2^ + 2as
s = Vi t + (0.5)at^2

s = vt (Horizontal component)

Where:
Vf = Final Velocity
Vi = initial Velocity
s = Displacement
t = Elapsed time.
a = gravity (-9.8m.s-1) - Newton's law of constant accleration.
* assumes velocity is constant.

Vectors:

Vectors have magnitude, direction and sense.
Always breakup the question into verical and horizontal components. (X and Y components)




Labelling:
Sine, Cosine and Tangent:
Question Solving Guide:

Examples:


Real World Problems:

[SSEH2280] LECTURE 1 - Biomechanics and sports science

Required Reading: Lab manual, Biomechanical basis of human movement (Hamill J and Knutzen K. 2003 )
- 39 lectures & tutorials
- 6 labs
- gait practical (2280)
- Mid Sem (15%), Final exam (70%), Gait practical (15%)


Muscle Names and Actions
  Knee Flexors (hamstrings): semitendinous, semimmbranousus, biceps femoris (2 heads)
Hip Extenders (quadriceps)
Rectus Femoris, vastus lateralis, medialis & intermedialis. 
 
Ankle Dorsiflexion:
Peroneus Tertius, tibialis anterior

Ankle Plantarflexion:
Gastrocnemius, soleus, peroneus longus, peroneus brevis,




  
Abduction: Deltoid, supraspinatus, Adduction: Latissimus dorsi, teres minor, teres major, coracobrachialis, triceps brachii. 

----------------------------------------------------------------------------
 Internal Rotation: Pectoralis Major, latissimus doris, teres major, subscapularis
External Rotation: Infraspinatus, teres minor,


Flexion: Pectoralis Major, Coracobrachialis,
Extension: Latissimus dorsi, teres major,











Scope of Biomechanics
 



- study of human movement using mechanics and applied anatomy.

Sport: technique development, injury reduction.

Clinical: Rehabilitation (checking gait, analyse surgery methods, alignment - technology), disease identification and progression, best surgical outcome consideration, improving movement, reduce loading leading to reduced diseases.

Occupational: Ergonomics. (back injuries in shearers i.e. identifying occupational problems)

- Learning path for Skill

Tactical - Technical - Physical - Mental
SSEH2280 looks at the Technical aspect.

- Deciding What technique to Teach

Use past experiences (i.e. grip)
Current world trends (keep up to date)
look for Flairs of athletes (gift of an athlete)

Link past experiences, current world trends, flairs (above 3) with biomechanics.


Cartesian Coordinate System (has x and y coordinates) describe 2D position/movement.


PLANE OF MOTION



- Sagittal: divides left and right
- Coronal/Frontal: divides front and back.
- Transverse: Divides top and bottom.
* Different angles are used for different measurements.

- Could measure front and back knee angle, forward lean of trunk (Sagittal)

- Trunk angle, shoulder/upper limb abduction/adduction (Frontal)

- Shoulder alignment, hip alignment (shows shoulder and hip rotations) (Transverse)

Outcomes:
 Preparation for Lectures: