Transcript for:
Lecture on the Fibula

we looked at the tibia you know while ago right I'm gonna feel really guilty if we don't also talk about the fibula there is a little bit less to the fibula so maybe brevity is the order of the day to day but fibular it is fibula little diddy slender long bone that sits alongside the tibia in the leg this is a left one so I should stick to left things today so we'll look at the bony bits will talk about the joints that it's involved with we'll talk about the muscles attached to it but not in my detail and go try and talk about the groups of muscles so you can work it out so they've had to remember a list of names see it right I want its function in the name of it right so the fibula is the name of the bone and the word fibula yeah all these words come on neo Latin things right but fibula was a brooch you know like I'm a brooch with a pin that you'd put on your clothing so the fibula represents the pin of the brooch when put with the tibula tibia that's why I guess called the fibula in Greek pepperoni Peron is the Greek word for brooch or a clasp the same idea which is why the muscles of the fibula and the nerves of the fibula get called fibula or peroneal one is from the Latin derivation one is from the Greek by the way with peroneal though you know that's gotten over here don't mix up peroneal with perineal which is different right perineal will be up in there well perianal which is similar again that's also up in there so be careful small Spelling's important if I want to talk about fibula fib you a is the name of the bone something that the something that belongs to the fibula so the possessive version of the fibula is fib ula are so we stick an hour on the end of it same with the ulna see students doing funny things in exams in the right thing so fibula bone Phoebe you'll our nerve belongs to the fibula all right so you look at when you write things down so if this is less glutes look at the left leg of this skeleton function of the fibula bone it's not weight-bearing the tibia is the weight-bearing bone of the leg and I think the fibula is so non-weight-bearing you can actually take a chunk out of the middle or take big chunks out of it and use it for bone reconstruction elsewhere in the body so its main functions are its forming the ankle joint here this shape of the ankle joint we've looked at before that's a function of the fibula and it's a site of muscle attached as we've got lots of muscles many of these muscles are attached to the fibula and the tibia and the interosseous membrane so muscle attachments forming the ankle joint that's why it's important now bony bits this is the head of the fibula and it has a neck leading to the head of the fibula and the fibula has a pointy bit at the top and the pointy bit gets called the apex off the head of the fibula now the head of the fibula is a good bony landmark you can palpate this yourself alright it's a very prominent bony love here and one of the reasons that landmark is interesting is you see here so here's the head of the fibula here this is the common fibular nerve ending its way around here so if you can palpate the head of the fibula you have an idea of where the common people the nerve is all right and then it has a shaft and then the lateral malleolus down here and the lateral malleolus which we'll also palpate here so the lateral part and malleolus that is fibula medial malleolus that is tibia so the lateral malleolus is the sticky-outy sticky dangly bit of the fibula thus forming this hinge joint for the ankle [Music] [Music] all right it's it's we're gonna make that shape and the bone down here that is then articulating with is the tailless so the tailless is gonna fit in this we need the tibia and the fibula to work together to form that joint and this means that injuries to the ankle and causes is lateral so injuries the lateral ankle can also involve the fibula and cause a fracture of the fibula fracture of the lateral malleolus and that sort of thing so when somebody has a bad ankle injury consider the slender little fibula because you know it's at risk somewhat now the shaft has got a cool shape it's kind of it's it's like triangular like the tibia is but it kind of twists as you go so on the left side still so that's proximal that's distal so this is the head of the fibula here and you see that that shape there it's got flat surfaces and it kind of twists as we go so if we need to talk about the surfaces of the fibula we talked about anterior posterior and interosseous surfaces so remember that between the tibia and the fibula runs an interosseous membrane literally you know into a bone in between the bones there's a membrane here which is helping tie these two bones together so there is is little or no movement between the tibia and the people are not likely on there in the radius we have loads of lovely movement supination pronation these two guys are fixed together tibia is taking the load the tibia the fibula and the interosseous membrane then become attachment sites for the muscle of anterior leg in the posterior leg the car all right and we might talk about medial posterior and lateral borders but you know joint then so the head of the fibula articulates with the fibula facet of the lateral condyle of the tibia at the proximal tibia fibula joint it is a synovial joint are planes and over your joints we've got a couple of fairly flat surfaces that could allow sliding over one another but in practice that joint is tightly bound with tough ligaments covering the synovial capsule whose job it is to limit to impair any movement there hold these two bones together securely the the distal tibiofibular joint is a singer as Moses a fibrous joint you know a bit like the the fibrous joints in the skull the sutures there so we have a whole bunch of fibers tying the the distal fibula to the distal tibia and tying those two bones together again limiting or preventing any movement between the tibia and the fibula so proximal tibia fibula joint distal tibiofibular joint you have that interosseous membrane which could be considered another joint between the two bones and then we have the ankle joint down here so we have the tailless articulating with the tibia and the fibula that are forming the shape of the of that joint and that is of course a synovial joint and there are lots of ligaments and lots of things supporting the ankle which I'm not going to go into here because that's a whole ankle thing isn't it all right muscles okay they're in the bound right so if you look posteriorly there's a groove around here which is a groove for the tendon of some of these muscles looping around here to get to the foot from the posterior compartment just like we saw the tibia doing anyway muscles wise what you want to do is you want to think well there are three fibularis muscles they're attached to the fibula their lateral fibularis longus fibularis brevis that's a common pairing isn't it then we have fibularis tercius so that's that's these guys over here so the fibula muscles are lateral and then if we look at the anterior compartment now we've got a muscle going over here I'm not going to mention but auntie really the anterior compartment we've got muscles that extend the toes or dorsi flex the toes and then we including the big toe so we've got a muscle for all the toes and then we've got a muscle for the big toe so we've got extensor hallucis longus we've got extensor digitorum longus those are attaching to the fibula bone and the interosseous membrane and the tibia and if we turn around postie really get after me meais that's more superficial that's this belly up here but in here we've got so Laius that's got some attachments to the fibula and then we've got tibialis posterior that's got some attachment to the the fibula and we've got again think about the toes on the opposite side we've got flex right because flexor hallucis longus and flexor digitorum longus so those muscles of the deep posterior leg and the anterior leg have some attachment to the fibula and other bits in there and the other one which I think most people forget is that so if the the head of the fibula is here oh look at this guy's a big guy it's coming down to eat he's attaching to the head of the fibula as well from the top this is biceps femoris of your hamstrings this is your lateral hamstrings the biceps femoris also has an insertion into the head of the fibula amongst other things alright so those are your muscles so you see how the fibula and then that interosseous membrane between the fibula and the tibia are actually really useful for all these muscles to attach them we need all these muscles so that we can we can control the ankle and the foot for our bipedal locomotion to be rather take for granted is that it that's it the fibula where it is it's functions bony bits joints and the muscles that attach to it all right until you've been done as you've done and done see you guys next week [Music]