The foot and ankle Flashcards
What is another name for the ankle?
talocrural
What is the articualtions that form the ankle joint?
Formed by distal ends of tibia and fibula (malleolar mortise) and trochlea of talus
What type of joint is the ankle joint and what movement does it permit?
Synovial hinge joint permitting two movements – dorsiflexion and plantar flexion
What surrounds the ankle joint?q
Surrounded by articular capsule that is weaker anteriorly and posteriorly
Is the ankle joint prone to dislocation?
No
What stabalises the ankle joint?
Good congruity between malleolar mortice and trochlea – the malleoli ‘grip’ the talus
What reinforced the ankle joint?
Reinforced by strong ligamentous ties between the bones of the ankle joint including:
distal part of the interosseous membrane
anterior and posterior tibiofibular ligaments
Why is dorsiflexion the most stable position of the anle joint?
The trochlea of the talus is wider anteriorly than posteriorly
During dorsiflexion, the anterior part of the trochlea moves between the malleoli
This spreads the tibia and fibula slightly, increasing their grip on the talus
What are the 3 seperate parts of the lateral ligament that reinforces the ankle joint?
Anterior talofibular ligament (weakest)
Posterior talofibular ligament
Calcaneofibular ligament
What is the attachments of the medial (delta) ligament?
The medial ligament of the ankle is attached to the medial malleolous and fans out to attach to the talus, naviular and calceneus via 4 insertions
What is another name for the medial ligament?
Deltoid ligament
What are the different movements of the ankle?
Dorsiflexion, plantarflexion, invesrion and eversion
What muscels allow dorsiflexion of the ankle?
Dorsiflexion is produced by muscles of the anterior compartment of the leg Tibialis anterior Extensor hallucis longus Extensor digitorum longus Fibularis tertius
What nerve and artery supplies the anterior muscle compartment of the leg that allow dorsiflexion of the ankle?
Supplied by the deep fibular nerve and anterior tibial artery
What muscles produces plantarflexion of the ankle?
Plantarflexion is produced by muscles in the posterior compartment of the leg (except popliteus)
What nerve and artery supplies the posterior muscles of the leg?
All supplied by the tibial nerve and posterior tibial artery
What is the role of the foot?
Support and transmit body weight
Acts as a lever to propel body forward during motion
Acts as a resilient spring to absorb shock
What is the advantage of the foot being made up of small bones?
If the foot was RIGID each impact with the ground would generate large forces
Instead foot is a series of small bones and ligaments that can deform to absorb shock and adapt to uneven surfaces
What bones makes the big toe?
Proximal and distal phalanx
What is another name for the big toe?
Hallux
What is the name of the joint between the tarsals and the metatarsals?
Tarsometatarsal joints
What type of joint is the Naviculocuneiform joints?
The naviculocuneiform joint is a joint between the navicular bone and the cuneiform bones
What articulations are invovled in Talonavicular joint?
The articulation of the talus with the navicular
What articulations are invovled in Calcaneocuboid joint?
The articulation of the calcaneus with the cuboid
What two joints make the transverse tarsal joint?
Calcaneocuboid joint
Talonavicular joint
What joints allow flexion and extension of the foot?
Flexion and extension occur at the metatarsophalangeal joints and proximal and distal interphalangeal joints
Can you abduct and adduct the foot?
Limited abduction and adduction occurs at the metatarsophalangeal joints
At what joints does inversion and eversion occur?
Inversion and eversion primarily occur are at the subtalar joint with some movement in the transverse tarsal joint
Subtalar joint is articulation between what two bones?
The subtalar joint between the talus and underlying calcaneus
Which muscles of the leg are invertors?
Tibialis anterior and tibialis posterior
What muscles of the leg are evertors?
Peroneus longus and peroneus brevis
What joint does Gout usually affect and what is ita reflection on?
Gout typically effects the first metacarpophalangeal joint
Gout Is reflection on diet and some medication
What type of inury is ankle sprains?
Most ankle sprains are inversion injuries with twisting of a plantar-flexed foot
What are the different calssifications of ankle sprains?
A first degree sprain is damage to only a few ligament fibres
A second degree sprain is damage to a more extensive number of ligament fibres, but the ligament remains intact.
A third degree sprain is a complete rupture of the ligament
Why is most ankle sprains inversion injuries?
The lateral ligament of the ankle is weaker than the medial, particularly the anterior talofibular part
How well do ligaments heal from ankle sprain?
Ligaments relatively avascular - heal slowly
If ligament detached from bone, fibres do not grow back into bone cortex as extensively - healed ligament usually weaker
Torn ligaments destabilise joint - predisposed to dislocation
What is the consequence of a eversion injury?
An eversion injury can pull the strong medial ligament, causing avulsion of the medial malleolus
The talus rotates laterally, fracturing the fibula
What is the action of the arches of the foot?
The arches of the foot help to distribute weight acting as shock absorbers and increase the flexibility of the foot
They also act as springboards for propulsion during walking, running and jumping
What are the 3 arches of the foot?
- Medial longitudinal (MLA)
- Lateral longitudinal (LLA)
- Transverse (TA)
What bones are invovled in the medial longitudinal arch?
Calcaneus, talus, navicular, 3 cuneiforms and medial 3 metatarsals
Which arch is more important the medial or lateral longitduinal arch and why?
The medial longitduinal arch as it is higher
How is weight transmitted on the medial longitduinal arch?
Weight is transmitted through the talus to the calcaneus and metatarsal heads
What does the lateral longitduinal arch compromise?
Comprises calcaneus, cuboid and lateral 2 metatarsals
What does the transverse arch compromise?
Comprises cuboid, 3 cunieforms and bases of the 5 metatarsals
Why do the arches need support?
The weight of the body would flatten the arches if they were not supported
What are the two mechanisms that support the arches of the foot?
Passive support includes ligaments and the shape if the bones
Dynamic support includes intrinsic and extrinsic muscles of the foot
What are the passive support of the longitduinal arches?
The plantar aponeurosis and plantar ligaments are the most important factors in maintaining the arches of the foot
What are the dynamic support of the longituindal arches?
Small intrinsic muscles reflexively contract and brace the longitudinal arch
Flexor hallucis longus and flexor digitorum longus (extrinsic muscles) also support longitudinal arches
What is the passive support of the transverse arch?
Passive support is through the shape of the bones, especially the wedge shaped cuneiforms
What is the dynamic support of the transverse arch?
Dynamic support is provided by fibularis longus and tibialis posterior
The tendons of these muscles cross the plantar surface of the foot like a stirrup
When does the medial longitduinal arch become apparent?
Presence of large amount of subcutaneous fat
After 3 years, subcutaneous fat is lost and normal medial longitudinal arch becomes apparent
The medial longitduinal arch is not in contact with the floor
What is the cause of Pes planus?
Can be flexible or rigid (i.e. fusion of tarsal bones)
Flexible more common – arch is present when not bearing weight but absent when standing
Usually caused by loose or degenerating ligaments
How is Pes planus exacerbated?
Can be exacerbated by gaining weight and/or spending a long time standing
What is the treatment for Pes planus?
treated with orthotics (specialised insoles) that support the arches of the foot
What is the consequence of Pes planus?
May be asymptomatic
can result in displacement of the talus infero-medially
this causes misalignment of the ankle and knee causing pain in these areas
can also decrease shock absorption by the foot leading to lower back pain
Name the 7 large tarsals of the foot?
Calcaneus Talus Cuboid Navicular Lateral cuneiform Intermediate cuneiform Medial cuneiform
What metatarsals does cuboid articulate with?
The 5th and 4th metatarsals
What metatarsals does the lateral, intermedaite and medial cuneiforms articulate with?
Lateral is with 3rd
Intermediate is with 2nd metatarsals
Medial is with 1st metatarsals
How many phalanges does the hallux of the toe have?
Only a distal and proximal one
What does a torn ligament in the ankle predispose a person to?
Ankle dislocation
Is a healed ligament as strong as a normal ligament explain why?
No it is weaker because the healed ligament does not grow as extensively into the bone
What are the plantar ligaments that support the longitudinal arch?
Short and long plantar ligaments
Plantar calcaneonavicular ligament
How does our feet look when we are born?
Everyone has flat feet –> filled with subcutaneous fat
