Gross Lecture 7 Flashcards
Does the fibula participate in weight bearing? What is its role in the formation of the knee joint? The ankle joint?
- Yes, but minimally
- not a part of the knee joint
- medial aspect of the fibula forms part of the ankle joint, together with the lateral malleolus of the tibia and trochlea of the talus
Describe the clinical consequences of damage to the common fibular nerve. How is this nerve typically damaged?
Foot drop and loss of sensation to the dorsum of food; individuals with damage to the common fibular n. walk with noticeable slapping of the foot on the ground and have difficulty walking on heels. Nerve is typically damaged from trauma to neck of the fibula, as it winds around it
List the bones that participate in the formation of the ankle joint
tibia (medial malleolus), fibula (lateral malleolus) and trochlea of talus
What ligaments stabilize the ankle joint? In what position is this joint most stable?
Lateral and medial (deltoid) ligaments; anterior and posterior inferior tibiofibular ligaments. joint is most stable in the dorsiflexed position
Describe the difference between dorsiflexion and plantar flexion, list the muscles responsible for producing each movement and their innervation
Dorsiflexion = approximate dorsum of foot to anterior leg; anterior crural compartment muscles; innervated by deep branch of common fibular n.
plantar flexion = approximate plantar surface of foot to posterior leg; superficial posterior crural compartment muscles (gastrocneumius and soleus mm.; also known as triceps surae mm); innervated by tibial n.
“Drop foot” is caused by a lesion to which nerve/nerve root?
common fibular nerve damage/L5 root
A lesion of which nerve/nerve root will make it difficult to “heel walk” and to “toe walk”
heel walk: (impaired dorsiflexion) caused by damage to common fibular nerve or L5 foot toe walk (impaired plantar flexion) damage to tibial nerve or S1 root
Describe the difference between pronation/eversion and supination/inversion, list the muscles responsible for producing each movement and their innervation. Where do these movements occur? Which ligaments are responsible for restraining each movement?
Pronation = sole of foot turned outward, with weight primarily on first metatarsal; fibularis longus and brevis mm., in lateral crural compartment; innervated by the superficial br. of common fibular n. the medial (deltoid) ligament is responsible for restraining excessive pronation of foot Supination = sole of foot turned inward, with weight primarily on 5th metatarsal; tibialis anterior m. innervated by deep branch of common fibular n. and tibialis posterior muscle innervated by tibial nerve; the lateral ligament is responsible for restraining this movement
Which is more common and why: pronation/eversion or supination/inversion injuries?
inversion (supination) injuries because lateral ligament of the ankle is not as strong as the deltoid ligament
How can a traumatic eversion injury result in fracture dislocatin of the lateral malleolus?
Also called a Potts fracture-dislocation; the medially directed force of the trauma tears the deltoid ligament causing a fracture of the medial malleolus; subsequent lateral movement of the talus and tibia can result in fracture of the lateral malleolus or, more commonly, the fibula
Damage to which ligament results in “flat feet”
spring ligament
Describe the clinical symptoms that accompany a lesion of the tibial nerve. Can an individual with such a lesion walk? If so, how is locomotion different?
If tibial nerve is damaged, individual has difficulty plantar flexing the ankle and toe walking. Walking with a tibial nerve injury may be difficult to near impossible, depending on severity, since plantar flexion of ankle is required for pushing off during locomotion.
