Ankle and foot Flashcards
what does the ankle do In terms of movement
- Mainly dorsiflexion and plantarflexion
Describe the talus
- Talas sits onto of the Calcaneus
- Calcaneus is the biggest carpal bone
- Talas articulates with the tibia and fibula
what forms the medial and lateral malleolus
- fibula – forms lateral malleolus and articulates with the talas on the lateral side
- Medial malleolus comes from the tibia and articulates with the talus
what part of the leg causes plantar flexion
posterior compartment of the leg causes plantarflexion
what compartment of the leg causes dorsiflexion
- Dorsiflexion – anterior muscle compartment of the leg
describe how the ankle is stable
- there is a small amount of wobble in the talus this is due to the shape of the talus
- the talus is more stable in dorsiflexion as the medial and lateral malleous is articulating with the thickest part of the talus whereas in plantar flexion it is at the thinnest part
is the ankle more stable in dorsiflexion or plantar flexion
dorisflexion
are you more stable in eversion or inversion
- Medial malleolus – shorter than lateral therefore you are more stable in eversion than inversion
describe what happens in extreme plantar flexion
calf muscles contract, pull the calcaneus of the ground they give the propulsion and momentum to move the heavy limb against gravity and the weight of it
what movements does the subtler joint do
inversion and eversion
where is the medial ligament
- from the medial malleolus of the tibia to the calcareous and navicular
what does the medial ligament prevent
– Very strong, stabilise ankle joint during eversion and prevent subluxation
– Prevent the talus from slipping out from under the medial
what it it called when the talus slips out from under the
called subluxation hen the talus slips out from under the medial malleolus
what is the lateral ligament made out of
- Anterior talofibular
- Posterior talofibular
- Calcaneofibular
what do you get when you damage the lateral ligaments
- get a sprained angle
what kind of injury is a sprained ankle
inversion injury
what is the most common damaged ligaments in a sprained ankle
- 15% of all athletic injuries
- Most common in Anterior talofibular and Calcaneofibular
describe what muscles and nerves cause dorsiflexion and extension
- Innervated by deep branch of common peroneal nerve
- Tibialis anterior, E.digitorum longus and E. hallucis longus (extensor for the big toe)
describe what muscles and nerves cause eversion
- Innervated by superficial branch of common peroneal
- Lateral compartment
- Fibularis longus and fibularis brevis
describe how the muscles in the leg get into the foot
- The muscles have long tendons that run into the foot across the ankle joint and these are held in place via the superifior extenson and inferior extensor retinaculum
describe where the dorsiflexors insert onto the foot
- Tibilaris anterior inserts on the median side of the foot
- Extensor hallicus longus goes down the the big toe
- Extensor digitorum longus geos to toes
what compartment does plantar flexion
posterior compartment
what can the muscles that do plantarflexion divide into
- Can be divided into Superficial and deep flexors
what are the superficial muscles
- Superficial 3 muscles attach via calcaneal tendon - gastrocnemius, soleus and plantaris – these do plantarflexion
what are the deep muscles of the posterior compartment
- attach to bones of foot
- tibialis posterior (behind the tibia)
- F. digitorum longus
F. hallucis longus – these go onto the sole of the foot and into the toe, these are the toe flexors
what are the toe flexors
- tibialis posterior (behind the tibia)
- F. digitorum longus
F. hallucis longus
what does the tibias posterior do
toe flexor
inverts the foot
what innervates the deep and superficial posterior compartment of the leg
- Tibia nerve innervates all of these muscles, runs between the deep and superficial compartment
what causes inversion of the foot
- Mixture of tibialis anterior going to the medial side of the foot – lifts the big toe side of the foot into inversion and tibialis posterior – comes to the medial side of the foot therefore when it contracts it also inverts
what does flexor digioturm longus do
Flexor digitorum longus – goes across the sole of the foot and to the toes, act as toe flexros and support the sole of the foot when we are standing up
what muscles join into the achilles tendon
Soleus and gastrocnemius goes onto Achilles tendon
how long is the ahcielles tendon
15cm
what happens to the achilles tendon
it can tear or rupture
- To repair it – complete rupture – needs to be sutured back into place, if it is a partial tear – can do physiotherapy to get it back
what happens if you damage the achilles tendon
- Unable to plantarflex and shape of the ankle disappears
what does the achilles tendon do
- Under tension – saves energy so when the muscles contract you don’t need much energy to release it
what are the retinaculum in the foot
• Extensor and flexor retinaculam
what do the externsor and flexor retinauculum do
– Hold tendons in place as they enter foot
– Tibial nerve and posterior tibial artery pass under flexor retinacula
– Deep fibular (peroneal) nerve and anterior tibial artery pass under the extensor retinacula
what do tendons run in
• All long tendons run in synovial sheaths
where is superior and inferior extensor retinaculum
- One at the distal end of the leg – superior extensor retinaculum
- One cross shape that goes over the foot – inferior extensor retinaculum
what can cause damage to the tibial nerve
- The tibial nerve and the posterior tibial artery come underneath the flexor retinaculum of the foot
- Can have tibial nerve tunnel and deep peroneal is compressed
- If there is damage to the tendon sheath they can compresse the nerve or artery supply to the sole or dorsal of the foot
what are the movement of the foot
- Dynamic – small micromovements of the foot to readjust the pressure and body weight
- Can flex, extend, adduct and abduct the toes can invert and evert the foot
what do the ligaments do in the foot
give stability between bones
• Ligaments are around the foot and on the sole of the foot that get stretched every time you take a step
• Ligaments stop the foot from spread out and the bones from spreading out
what are the ligaments of the foot
• Medial side
– Spring (plantar calcaneonavicular) ligament continuous with deltoid ligament
• Lateral side
– Long and short plantar ligaments
what is more stretchy ligaments or tendons
ligaments - can give stretch
describe the spring ligament
- This is a planar calcaneovaicular ligament
- On the plantar surface – this is the spring ligament
- This stops the separation of the bones
describe the long and short plantar ligaments
- Go to the base of the meta tarsals
- Help stop the separation of the bones in the foot when standing
what do intrinsic muscles of the foot do
- For precise movements
- Constantly contracting and relaxing responding to dynamic changes in 3-4 layers
- Move the foot a little bit to get better contract
describe the structure of the intrinsic muscles of the foot
- There are in layers
- In the sole of the foot
- Go from the calcaneous forwards to the toes
- They are mainly flexros – muscels that grip on to the surface
- Help to dynamically change the bones positions in the foot to give a better contact in the ground
what are the arches of the foot
- Medial longitudinal
- Lateral longitudinal
- Transverse arch
describe the transverse arch
have to put two feet together to get a full arch
what do the arches of the foot do
- Need to be able to move the foot to act as a shock absorber, to help store energy to propel forward
describe the medial longitudinal arch
- Medial side arch doesn’t make an impression in the sand
- Tall arch
- Resilient due to a large number of bone compartments
describe the lateral longitudinal arch
- Flatter as fewer bones
- Talus transmits the body weight through it
what is newtons third law
- Newton’s 3rd law: Every action has an equal and opposite reaction.
describe the weight distribution
- 50% goes from the talaus to the calcaneus, other 50% goes forward to the rest of the foot
- From the front of the foot we are digstributing 33% to the big 2nd and 3rd toe and 17% goes down the little toe and 4th toe side
what would the body flatten if they were not supported
longitudinal arches
- Have to have something that is counteracting the gravity and weight that is pushing onto the arches
where is the body weight in weight distribution
- In quiet stance body weight transmitted through talus bone,
- passes equally backwards (into the calcaneum) and forwards.
how are the longitudinal arches maintained
- Dynamic and passive support
describe how dynamic support works
- muscles that can contract and some cannot, depends on how much of the muscle contracting gives you a different pull
- Muscle tendons that insert into apex of arches tend to increase their height (e.g. tibialis anterior)
- Muscle tendons that run through the sole of foot. Like ligaments they prevent separation (e.g. fibularis longus and small intrinsic muscles), intrsinc plantar muscles
describe how passive support works
- Shape of the bones allows them to interlock
- Longitudinally arranged ligaments prevent separation (e.g. long and short plantar ligaments and the plantar calcaneonavicular (“spring”) ligament)
- Calssified as part of passive support – ligaments keep the bones locked together and stop them from moving
what is the transverse arch maintained by
- Maintained by same muscles and ligametns as longtiduinal arches
what do the transverse arches do
- These arches deform when walking
- Act as shock absorbers
- Propulsion – spread out – take the weight of and recoils which helps propel you forward
what are arch problems
- Can become hypertonic then they pull too much of the arch and lift it too far you you end up with pes cavus
- If the muscles are too weak or paralysed then you get pes planus – foot and arches would collapse – flat foot
how do bunions form
- 50% of body weight goes forwards and to the ball of the foot
- Movement of the great toe towards the 2nd toe
- 90% inherited during a connective tissue disorder but can result from tight pointy shoes
how do you fix bunions
- Can be surgically corrected it or you can wear a brace to help straighten the toe – causes a problem with weight distribution and pain in the feet
