Foot SDL Flashcards
Label the navicular, cuboid, medial, intermediate and lateral cuneiforms
What structures articulate at the subtalar joint? What movements occur here?
- Calcaneum and talus
- Eversion and inversion occurs here
The calcaneum can be fractured, although it is a thick bone and considerable force is required. How are these fractures usually caused?
Calcaneal fractures are usually caused by a person falling from height and landing directly onto their feet (or foot).
Gout and bunsions are 2 conditions that commonly affect which joint in the foot?
The first MTP joint
What is a bunion?
It’s a bony bump that forms on the joint where your big toe meets your foot – called the metatarsophalangeal (MTP) joint.
What is gout?
A type of arthritis - characterised by sudden, severe attacks of pain, swelling, redness and tenderness in the joints, often the joint at the base of the big toe.
How does gout occur?
Urate crystals accumulate in your joint, causing the inflammation and intense pain of a gout attack.
Urate crystals can form when you have high levels of uric acid in your blood.
Your body produces uric acid when it breaks down purines — substances that are found naturally in your body.
Sometimes either your body produces too much uric acid or your kidneys excrete too little uric acid –> urate crystals
How do the tendons of EDL and EHL travel? Where are they visible?
Travel over the dorsum of the foot to their insertions. These tendons, along with that of tibialis anterior, are usually visible under the skin of the foot.
Where do most of the intrinsic muscles of the foot lie?
In the sole of the foot (a much smaller number lie in the dorsum)
How many instrinsic muscles are there in the dorsum of the foot? What are they?
3:
- Extensor digitorum brevis (EDB)
- Extensor hallucis brevis (EHB) – this muscle is part of EDB.
- A group of 4 dorsal interossei (between the metatarsals)
Function of extensor digitorum brevis?
Aids the extensor digitorum longus in extending the medial four toes at the metatarsophalangeal and interphalangeal joints
Function of extensor hallucis brevis?
Aids the extensor hallucis longus in extending the great toe at the metatarsophalangeal joint.
Function of the dorsal interossei?
Abduct digits two to four and flex the metatarsophalangeal joints.
Innervation of the dorsal interossei?
Lateral plantar nerve.
Innervation of extensor digitorum brevis?
Deep fibular nerve
Innervation of extensor hallucis brevis?
Deep fibular nerve
Which artery can be palpated on the dorsum of the foot? Which tendon does it lie lateral to?
Dorsalis pedis artery - travels lateral to the extensor hallucis tendon along its course to the big toe
Dorsalis pedis is a continuation of which artery of the anterior leg?
Anterior tibial artery
In addition to the intrinsic muscles, what muscles are found in the sole of the foot? How do these muscles enter the foot?
- Tendons of the extrinsic flexors of the toes – FDL and FHL
- Tibialis posterior also inserts into the plantar aspect of the foot (but does not act on the toes).
These muscles descend from the posterior leg and travel posterior to the medial malleolus and into the sole of the foot.
The sole of the foot is covered by tough skin. What is deep to this skin?
A sheet of tough fibrous connective tissue called the plantar aponeurosis (or fascia).
Describe the difference in the plantar fascia medially, laterally and centrally?
The plantar fascia is thick and strong centrally but weaker in its medial and lateral parts.
Function of the plantar fascia?
The plantar fascia supports the arches of the foot and protects the deeper structures within the sole.
What projects from the plantar fascia? What does this merge with?
Fibrous bands project from the plantar fascia to merge with the fibrous sheaths that surround the long flexor tendons.
What lies between the skin and the calcaneum?
A fat pad
What intrinsic muscles are found in layer 1 (most superficial) in the sole of the foot? What are their actions?
- Flexor digitorum brevis –> Flexes the lateral four digits at the proximal interphalangeal joint
- Abductor hallucis - Abducts and flexes the great toe
- Abductor digiti minimi - Abducts and flexes the 5th digit
What intrinsic muscles are found in layer 2 of the sole of the foot? What are their functions?
- Lumbricals –> Flexes at the metatarsophalangeal joints, while extending the interphalangeal joints
- Quadratus plantae –> Assists flexor digitorum longus in flexing the lateral four digits.
- (the tendons of FHL ad FDL; extrinsic muscles)
Which tendons do the lumbrical muscles take origin from?
There are four lumbrical muscles in the foot. They are each located medial to their respective tendon of the flexor digitorum longus. Originates from the tendons of flexor digitorum longus.
What intrinsic muscles are found in the 3rd layer of the sole of the foot? What are their functions?
- Flexor hallucis brevis –> Flexes the proximal phalanx of the great toe at the metatarsophalangeal joint
- Flexor digiti minimi –> Flexes the proximal phalanx of the fifth digit
- Adductor hallucis –> Adduct the great toe. Assists in forming the transverse arch of the foot.
What intrinsic muscles are found in the deepest layer of the sole of the foot?
The plantar interossei - there are 3 of these
Where is the dorsalis pedis palpable?
Just lateral to the tendon of extensor hallucis longus
What does the posterior tibial artery descend behind before entering the foot?
Descends behind the medial malleolus
Where is the posterior tibial artery palpable?
Behind the medial malleolus
What does the lateral plantar artery go on to form?
The lateral plantar artery forms the deep plantar arch which then anastamoses with the deep plantar artery
What does the dorsal venous arch drain into medially and laterally?
Medially into the greater saphenous vein and laterally into the small saphenous vein
Which malleolus does the great saphenous vein ascend in front of / behind?
Ascends anterior to the medial malleolus
Which malleolus does the small saphenous vein ascend in front of / behind?
Ascends behind the lateral malleolus
What is the skin of the dorsum of the foot mainly innervated by?
2 branches of the common fibular nerve - the deep and superficial fibular branches
What is the skin of the plantar surface of the foot mainly innervated by?
By the tibial nerve itself or its two terminal branches - the medial and lateral plantar nerves
How is the plantar reflex tested?
To elicit this reflex, an item with a firm, blunt tip (ideally a covered ‘neuro-tip’ or tongue depressor) is used to stroke the sole of the foot in one swift, continuous movement, from the heel, up the lateral side of the sole and then across the ball of the foot towards the big toe, as shown below.
What is a normal response to the plantar reflex?
Plantarflexion (curling) of the toes. This response is conventionally described / documented in clinical practice as ‘normal plantar(s)’, ‘down-going plantar(s)’ or a ‘normal / negative Babinski sign’.
Is extension of the big toe in response to the plantar reflex normal or abnormal? What is the exception to this?
Extension of the big toe in response to this stimulation is abnormal (except in infants) and is described as an ‘up-going plantar(s)’ or a ‘positive Babinski sign’.
