This session was taught by: Mr Desai who is a consultant T&O surgeon with specialist interest in knee and hip.
Session 4: Lower Limb Anatomy
Summary
In this extensive on-demand teaching session, a lower limb and knee specialist discusses the anatomy of the knee, breaking down its components such as bones, ligaments, muscles, and the menisci. This insightful session also covers causes and signs of knee injuries, including tears of the menisci and ruptures of the cruciate ligaments. The specialist also demonstrates how the knee functions and how injuries can be repaired. After moving through understanding the knee, there is a short session on hip anatomy. This detailed session is essential for medical professionals looking to gain in-depth knowledge related to knee and lower limb anatomy and issues.
Description
Learning objectives
- To understand and identify the anatomical structure of the knee joint including the bones, ligaments, muscles, and menisci that comprise it.
- To comprehend the dynamic and static stabilizing forces in the knee joint and explain how they contribute to its function.
- To recognize common injuries and conditions that can affect the knee joint and how they can be diagnosed through clinical presentation and imaging.
- To interpret and discuss potential treatments for knee injuries and conditions including therapeutic exercise, rehabilitation, and surgical options.
- To understand the articulation of the patella, its stabilizers, and common conditions affecting it including patellar dislocation/subluxation and arthritis.
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Computer generated transcript
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The following transcript was generated automatically from the content and has not been checked or corrected manually.
Uh Good evening everybody. Can you all hear me? CJ? I presume they can hear. Yes, we can. OK. Great. And I'm going to share my slides. Uh Please feel free to interrupt at any time. Um And I hope it, it is a useful session for you guys. Can you see my slides? Uh Yes, we can. OK. Uh So good. Uh Good evening. I am a knee uh lower limb specialist and a knee specialist from Kingsville Hospital. So, can I start with the knee, please? Seeing as it's a bit more, it's my prerogative. So there we are. So uh I understand this is for part one. So it is largely anatomy based. Uh And uh what I want to do is uh say uh sort of look at things. Uh let's go through this. That's the knee joint. OK? The bones that make the knee joint are always the femur and the tibia. But the femur also articulates with the patella, which is the constant sesamoid bone. It is the only constant sesamoid bone and it is the largest sesamoid bone in the body. When we say it's a sesamoid bone, it grows uh within the muscle of the bone uh rather than uh within the muscle, rather than a standalone bone there. Uh So the articular surfaces is between the femur, the patella, as well as the tibia. The stabilizing forces around the knee joint are static or dynamic. In terms of static stabilizers, you have the medial collateral ligament over here which has a superficial part and a deeper part underneath. There is a lateral collateral ligament. There is the anterior cruciate ligament so called because it is anterior on the tibia and the posterior cruciate ligament which is from the back of the tibia. The anterior cruciate ligament goes from the front of the tibia to the back of the femur. And the posterior cruciate ligament goes from the back of the tibia to the front of the femur, which means they form a cross in between them as they uh go within the joint. And hence, they are called the cruciate ligaments. The point at which they cross over is the point where the tibia can pivot around the femur so that you get rotational movements around it, you get slight uh rolling movement between the femur and the tibia. But you also get rotational movements around the femur and the tibia. And you can also see that when that rotational movement exceeds or the force of it exceeds the strength of the ligaments, it can cause a rupture of the two ligaments there. Uh other stabilizers and movers of the knee joint are the groups of muscles that we have around it. The biggest group of muscle is the quadricep muscle, which is four different muscles starting on the front of the femur, going onto the knee joint, the one muscle. However, the rectus femoris crosses both the hip joint as well as the knee joint. And hence, it has a function on flexion at the hip as well as extension of the knee joint. The other two muscles are the vastus medialis and the vastus lateralis. And underneath the rectus femoris is the vastus intermedius. The muscles on the inside of the leg which cross the adductor longus stops at the upper end of the femur in the AUC tubercle. But the sartorius muscle is one of the uh gyros tendon which comes from the pelvis onto the tibia. The other muscles which are part of the gyros tendon which stabilize the pelvis around the femur, uh around the tibia is also the Semitendinosis muscle, which is this one over here as well as the gracilis muscle. And each of these muscles comes from the three different bones. So the sartorius comes from the uh from the uh ilium, the gracilis comes from the pubis and the semitendinosus comes from the ischium, the three bones of the pelvis, all of which are attached onto the anteromedial side of the knee joint and the place where they are attached, they are in the shape of a goose's foot. And that is Why? And a bursa over there is called the pes anserine bursa, which sometimes gets swollen and can give rise to bursitis over time. Uh the muscles at the back end of the thigh, which stabilize the knee thigh and the leg which stabilize the knee joint are the medial hamstrings, namely the gracilis, the semitendinosis and the semimembranosus, the lateral hamstring, which is the biceps muscle, the muscles of the leg or the calf, which is mainly the medial and the lateral head of the gastrocnemius. And you can see that if the quadriceps are weaker, then the gastrocnemius can also bring about an extension of the knee joint. The quads cause an extension are responsible for extension at the knee joint. The uh gastro gastrocnemius muscle is responsible for the extension of the knee joint. Whereas the uh hamstring muscles are responsible for the flexion of the knee joint. The plantaris muscle, as you can see over here comes from the lateral side of the femoral condyle and is attached to the back of the tibia. And that is responsible for rotation of the tibia or the screw home mechanism or the locking or the unlocking of the knee joint. When you are standing perfectly with your knee, fully extended, the knee is locked because the tibia externally rotates on the femur. And in this way, all your muscles can relax and otherwise they are constantly firing and can lead to fatigue in the long run when the knee starts flexing the tibia internally rotates, unlocks the knee joint and then the muscles take over that rotation is the one that happens between the cruciate ligaments and in deceleration forces. So when you are running and you suddenly stop or when you're jumping and you land and the body twists with the foot firmly planted is what causes a rupture of your cruciate ligaments. In addition to the ligaments and the muscles, the knee joint also has the menisci which are the cshaped me, uh uh cartilage surface, uh substances inside the knee joint which act as shock absorbers between the femur and the tibia. And they help take off the pressure or increase the surface area over which the pressure is transmitted naturally. When the femur and the tibia twist and rotate. It also puts the meniscus along with the cruciate ligament at a risk of injury. And you can get bucket handle, tears of the menisci in the elderly, the fabric of the meniscus degenerates and similar sort of movements may give rise to degenerate test rather than bucket handle tests. And on an MRI scan, you can just about see that white line which is there within the posterior horn of the medial meniscus and it exits at the under surface of the joint and the point of tenderness where people feel it is on the poster medial aspect of the knee joint. This is what a bucket handle tear looks like. And if it is reducible, then we would like to repair it. Now, the thing about repairing a meniscus is that the blood supply is only in the outer third of the meniscus and the inner two thirds does not have any blood supply or lymphatic supply. So, unless the tear is in the red and the red zone or the red and white zone, it will not heal up. But taking a meniscus out predisposes patients to arthritis because it increases the force on the articular cartilage and then predisposes it to degenerative changes. That is what a degenerate meniscal looks like and often is a flap. And these meniscus give rise to mechanical problems such as locking inside the knee joint. There is how you can see that the ACL ruptures with the foot, firmly planted, the body externally rotates, puts the ACL at risk, the commonest uh mechanism that it would happen. It is uh on a football field or uh on a netball field. OK. And the test we would do is the anti drawers test. And when the hamstrings are relaxed, the tibia will move forward whereas the ACL should stop it from moving forward. Uh So when we are performing an ac uh anti test, I have to make sure the hamstrings are relaxed. What it also tells us is that when the ACL is injured as part of the rehabilitation for an ACL injury and or after surgery, the rehabilitation of the hamstring or strengthening of the hamstrings is of crucial importance because it brings the tibia backwards and stops it from rotating, uh sliding forward, which is what gives rise to the subjective feeling of instability in patients. When we treat them, we would often treat them with surgery. And uh we would use one of the hamstrings, usually the semitendinosis, which is uh technically, we can get rid of it because it contributes only 5% of the strength of the knee flexion. Uh And, but it gives us about three times the strength of the normal ACL. So we can use that for ACL reconstruction uh going to the patella and the patella anatomy. You can see that the patella articulates with the femoral trochlea uh which is uh and the shape of the femoral trochlea is in the shape of AJ starting laterally going down immediately. The patella is usually central over the femoral condyle and it also has dyn uh static and dynamic stabilizers. The static stabilizer is the medial patellofemoral ligament and the lateral and the medial retinaculum. And the, the dynamic stabilizers are these quadriceps muscles which pull medially as well as laterally. And you can see that the medial one is flesher and the lateral one has more tendon over there. So if you get pain inside a joint, then the muscles that move the joint will start weakening and the fleshy muscle weakens more than the uh muscular tendinous, uh part of it, which means the patella wants to move more laterally. So it then causes dislocations and subluxations or once it has occurred, then the weakness in the muscle uh predisposes it to keep happening again. So part of the rehab is to strengthen the quadricep muscles over here. But equally, we can reconstruct this MPFL with uh either artificial or another tendon. So that is what it is about when we look at articular surfaces, look at different levels of degeneration, which can give rise to anterior knee pain. Ok. And we don't want to go through there. Part of arthritis, which is a degeneration of the articular surface. You get loss of joint space, you get deformity, you get subchondral sclerosis and you get large osteophyte formation at this stage. The joint is well and truly damaged. And the only thing that will help is a joint replacement where what we are doing is restoring the alignment of the joint from what was a varus alignment? Because the distal part has gone medially uh to restoring it to a straight line with the hip, knee and ankle axis together and replacing the damage and the disease portions with metal and plastic over here. And we can either do total knee replacements or we can do partial knee replacements or we can sometimes do isolated patellofemoral replacements as well. I'm going to move on from the knee and I'm going to go on to the hip before I move on. Are there any questions from here. If there's no questions at present, you can continue. Thank you so much. Fine, going to the hip. This is one of the things that we talk about is let's look at this patients complain of pain around their hip. They will either say it is here or it is here or it is here. And the hip joint pain is most frequently felt in the anterior joint line or in the groin or over the greater tranter pain over the greater tranter or this part of the hip, which is the posterior part of the pelvis is most frequently referred pain from the lumbar spine and pain in the groin is most often hip related pain on occasions, the hip pain is also felt in the knee joint and patients with significant hip problems in terms of arthritis might be really sent by because of the saying that they have knee pain and the reason they get is that the hip and the knee share a common nerve root of innervation, which is the L3 and the L4 nerve root uh nerve roots which start from the lumbar plexus. So frequently, hip pain is referred onto the knees because of the shared nerve root. And that is why we always say whenever you examine uh you examine the joint above and the joint below, and you also examine the neurolog, distal neurological. So, distal neurological because you could get referred pain from the back as well. For any conditions you will see. Ok, let me see what I can do. Not much here, but I'm going to show you something different. Bear with me, please. Nope. Ok, let me go through there. Right? When we are examining a hip and you ask somebody to straight leg raise, they're using the ileo muscle to flex the hip joint. When they have pain on resistance against flexion of the hip joint. It is because the joint reaction forces increases and what is worn out over here, virtually bone on bone, uh will have more pressure put on across it. And uh that is why they feel the pain if the pain is not in the front, but is pain at the back when you are trying to lift it up, that is sciatic pain, stretch of the sciatic nerve, which comes from the lumbar spine, from the lumbar spine. Uh the sciatic nerve starts at L2 L3 L4 L5 and S one. So from the back all the way to the toes, the sciatic nerve is approximately 1 m long. And by doing a straight leg raise, we are increasing the length of the sciatic nerve across from here to here by about 15 to 20% which is why they get a pull if there is a tethering of the sciatic nerve, which is why you get a positive sciatic stretch test when we do an internal rotation movement at the hip and an external rotation movement. These are the movements that are brought about by the short, by the long external internal rotator, which is again, the Iliopsoas muscle, which crosses from the pelvi from the spine anteriorly and the pelvis anteriorly and attaches onto the lesser trochanter. Furthermore, the external rotators are the short external rotators which are the two Gelli, the superior and the inferior glime and the pyriformis muscle at the back. In addition to that, the main gluteus muscle, which is the gluteus medius and the gluteus minimus help in external rotation of the hip joint that brings me to the gluteus medius muscle. When we walk and you are standing onto one leg, it is the gluteus medius on that side, which has to actively contract to stop the pelvis from falling down on the other side. So if you have a pathology in the hip joint or, or damage to the gluteus, the superior gluteal nerve, which supplies to the gluteus medias muscle, then that pelvis drops causing a trendelenberg sign. OK. Uh So in effect, the pathology is on this side when the left side sinks. So the sound side sags is that OK. Uh That's how you would remember uh when you're doing a trend burg gait. Uh Similarly, when we do a hip replacement on somebody, the approach to the hip could be an anterolateral approach or a posterior approach. And in the an interlateral approach, the gluteus medius is cut through and there is a risk to the superior gluteal nerve which then causes a paralysis of the anterior part of the gluteus medius muscle and then can cause trend bug gait. Through the posterior approach, the sciatic nerve is at risk which can then give rise to a foot drop for the patient. So there is some application to it in terms of the pelvis, I don't have better diagrams, but this is the ilium, this is the ischium and this is the pubis, the two pubic rami, superior pubic ramus and the inferior pubic ramus meet at the pubic symphysis, which is a fibrous joint uh through the obturator foramen past the obturator muscles which go to the back of the uh hip, as well as the obturator nerves on the ischia is where on the ischial tuberosity is where we sit on. And that is supplied by the L3 nerve uh by the S3 nerve. And where we walk on in the foot, on the heel is the S one nerve. So you walk on your S one and you sit on your S threes uh from the pelvis pubis and the ischium, the three muscles that come and go to the front of the tibia are the phan in muscles. Similarly, you would get the adducted muscles which start on the pubis and attach to the medial side of the femur. The hamstring muscles are from the ischium which is the back end and are attached to the back of the knee joint and back of the femur and the side muscles come from the gluteus site. And it is important to remember that the balance between the medial and the lateral group of muscles as well as the abductor muscles is what helps in the stability of our walking. The iliopsoas muscle is attached to the lesser trochanter and comes from the, the iliacus comes from the uh inside of the ilium. And the psoas comes from the uh transverse processes of the lumbar vertebrae. I'm going to temporarily get off this presentation and go on to another presentation so that I can talk to you more about the anatomy of that. When we have an intracapsular fracture of the neck of the femur, that femoral head is at risk because when you get an intracapsular fracture across here, it damages the medial and the lateral circumflex arteries as well as the retinacular arteries which come on the superior surface of the neck, which then in an elderly puts the head at risk because the contribution of the artery from the ligamentum teres is very minimal in the elderly. And this is why when we get intracapsular fracture, neck femurs, we would tend to do uh replacement. There is a intracapsular fracture, neck femur, we would do a replacement uh because that head is at risk and avascular necrosis can occur between one and two years after this fracture. So, in the elderly, we would do a hemi or a total hip replacement when there are extracapsular fractures, which means that the capsule is attached to the uh between the greater and the lesser uh tranter anteriorly and at the back of the neck, posteriorly, it doesn't damage the blood supply to the head of the femur, which means we can fix them uh clinically on the tip of the greater trochanter is where you get the gluteus muscle attached to the gluteus medius. And the gluteus minimus at the posterior medial side of the greater trochanter is the pyriformis fossa where the pyriformis from the sacrum gets attached, but it is also frequently the entry point for a for an intramedullary nailing of the femur. Uh and on the very occasion, especially if you were in a young child, it could damage blood supply there but rarely at all. So the hip joint capsule on the front starts in the uh roof of the acetal attaches to the greater the trich and at the back attaches to the middle of the neck over here. Ok. Uh The muscles that come are from the back of the ilium and as well as the acetabulum, which is where you get the pyriformis muscle, the superior Glaus, the corus femoris and the inferior globuli muscles over here at the front, the hip muscles come and attached to the lesser trochanter. The knee muscles start from below over here and the quadriceps, the rectus femoris starts from the crosses the hip joint over the, the reflected head starts uh uh the acetabulum and the straight head comes from the femur, the two heads become the rectus, femoris, vastus intermedius is from the front, vastus lateral is from the side, vastus medial is from the uh inside. OK. I'm going to temporarily at least skip through this because there is some foot and ankle stuff that I want to talk to you about as well because I understand that the mcs, the foot and ankle stuff is very important. The ankle joint is made between the tibia talus and the lateral malleolus or the fibula. It is mainly called the tibiotalar joint, which is the ankle joint and on dorsiflexion, it will you, you get two ranges of movement just in one plain dorsiflexion and plantar flexion. Whereas inversion and aversion will happen at the subtalar joint which is between the talus and the calcaneus. Yeah, the ankle joint and then the foot, the foot is a combination of 28 bones and 54 joints between the ankle and the foot. It allows the foot to accommodate for all sorts of uh pressures as well as uh instabilities of walking on uneven surfaces and how it takes over uh the shock between the various ligaments and the muscles, the muscles in the front of the leg, which is mainly the tibialis, anterior muscle, which is attached on to the navicular over here. And the tibial is posterior muscle which comes from behind the tibia and goes onto the under surface of the first metatarsal. Over here, the Peroneus muscle that comes lo longus and the brevis, the brevis attaches to the fifth metatarsal base over here, but the longus goes underneath the foot and meets uh underneath the head of the first metatarsal. And between the Peroneus longus and the, and the tibialis anterior muscle which is onto the navicular, it holds the arch of the foot up together. Uh And they are responsible for uh having the medial longitudinal arch. If you lost your medial longitudinal arch, you would get an acquired flat foot, which is often as a consequence of an attritional rupture of the tibialis posterior tendon that we get over here. Tibialis, posterior is attached on the under surface here. And the peroneous longus comes from this side. Muscles at the front are the extensor digitorum which then form tendons and go across the various uh metatarsals as well as the phalanges. These muscles are held down by two different retinaculum. There is the ankle, superior, uh anterior retinaculum and the inferior uh anterior retinaculum which divides into a y shaped form. Uh If you lost these retinaculum or we damaged them during surgery, then they would cause bow stringing of these muscles and they would lose their mechanical advantages. The peroneal are underneath the peroneal retinaculum and come from behind the lateral malleolus. There is a muscle on the dorsum of the foot which is known as the Peroneus tertius, which also acts as a small extensor of the foot region. The biggest muscle is the tendo achilles, which is a combination of the gastrocnemius muscle and uh the soleus muscle. The gastrocnemius, as I said earlier, starts from the back end of the uh medial and the lateral femoral condyles, which means they cross the knee joint as well as the ankle joint. Whereas the soleus only cross comes from the back of the tibia and only crosses the ankle joint. And the commonest place where it is injured is approximately 5 to 7 centimeters above the insertion on the calcaneus because this area becomes relatively avascular. And the commonest age group is in the early forties. When the vascularity, vascular supply goes through a change and temporarily for a year or two, this vascular supply changes the muscle fibers, uh the tendon fibers can degenerate and it's often that midlife period when somebody wants to try getting fitter again. And January, February, after Christmas, everybody goes, joins the gym. They want to start playing squash because they played 20 years ago or they want to start running and they suddenly feel a pop at the back of their calf or their heel as if somebody has hit them and their tendon ruptures. And as part of the examination would be, uh you'd get them to nail, you'd squeeze the calf. And if the foot moves, then uh the tendon is intact. If the foot doesn't move, the tendon is ruptured, this is called a simmons test. Uh Also in terms of examination, especially if you are going to examine somebody younger or somebody who walks on tiptoes, uh, when you dorsiflex their ankles and the ankle doesn't come back to neutral position or what we call as a plantigrade position, you bend, you flex the knees. And if the ankle still remains there, that suggests a tightness in the gastrocnemius as well as the soleus. But with the flexion of the knee, the gastrocnemius tends to get uh relaxed. And if it is still tight, it would suggest an isolated soleus tightness. And then in patients who have cerebral palsy or who have different other muscular conditions, spasm conditions, we can treat them by either lengthening them or injecting them with Botox injections. In terms of the, between your tibialis posterior here and the extensor digitorum at the base of the first metatarsal is often where you would feel your dorsalis pedis artery. And when you see your patient and you feel for the dorsal liped artery on the odd occasions, 5% of our patients or 5 to 10% of the patients do not have a dorsalis pus artery. And the first thing you do is you palpate on the other side because if they don't have it on one side, they're unlikely to have it on the other side. But if you can find it on the other side but not on the injured side. Then you do a Doppler scan to assess whether it is damaged or not. Uh So, dorsalis pedis artery is palpable here, posterior tibial artery is palpable halfway between the medial malleolus. That's the lateral malleolus. This is the medial malleolus, halfway between the medial malleolus and the calcaneus. Under the medial retinaculum is where your neurovascular bundle would pass between the tibial is between the flexor hallucis longus and the achilles tendon. At the back end over there in the foot, there are several muscles, the long muscles from the extensor digitorum and the flexor digitorum and the flexor helosis come as tendons and there are short intrinsic muscles inside the foot. Uh And there are several of these uh including the abductors and the abductors of the big toe, the short abductor, the long abductor, short flexes, the long flexes and they are responsible for the biomechanics of the foot. In orthopedics examination, we tend to look for alignment, orthos and pus stands for straight feet, which is how we got our name as orthopedic surgeons because once upon a time, we would work on straightening uh deformed child, uh deformed feet in Children or club feet. So we became orthopedic surgeons. Straight alignment of the foot is is uh important because it helps transmission of pressure from the different bones and joints up onto through the ankle joint through the various muscles all the way up towards the pelvis. What you can also see that when feet are put into shoes, the muscles don't always function. You get tight shoes and you get deformities such as hallux valgus, then the sesamoid bone under the head of the metatarsals will displace on the sesamoid bones are attached to lung flexes and the short abductors and once they are displaced, they become tighter and they set up a vicious cycle so that the deformity gets progressively worse. Similarly, you will see patients will sometimes present to ed with a fracture at the base of the fifth metatarsal, which is an avulsion fracture, which comes from the peroneous brevis muscle, which is attached to the base of the fifth metatarsal. Over here. When you look at these patients, they might have swelling and bruising because of the damage to the muscle or the injury. And when you assess them, you're going to assess for the achilles tendon. You are going to assess the lateral malleolus, medial malleolus and the navicular and the calcaneus because any one of these could be injured. If you look at the foot joints between the head of the talus and the navicular and between the Calcaneus and the cuboid, the telo navicular joint and the calcaneocuboid joint, which are part of the big tarsal joints are a straight line and these lines are known as the chopin's line or the chopin's joints. Chopin used to be a surgeon in the French Napoleonic Army and he would take people's feet off across here when one fell swoop. And that's how functionally the talar navicular calcaneocuboid and the subtalar joint make a reverse ball and socket joint where the head of the talus is the ball and the ca navicular cuboid and the Calcaneus make a socket around it and they tend to move there. Uh some patients who I in vascular conditions, the chopin's joints are important also in injuries. The tarsal metatarsal joints are important because as you can see over here, second metatarsal is the longest and goes furtherest behind forms the keystone uh between the medial intermediate and the lateral CIF fromm bones. And that holds up your medial longitudinal arch together. And in Lis Frank's fracture dislocations, you would get Tarso metatarsal joint injuries. Uh And the list Fran ligament is between the medial CIF and the base of the second metatarsal between the calcaneus and the navicular and the cuboid. You can sometimes in young adults and Children get tarsal coalition and they form as one bone which can give rise to different pathologies, especially flat, uh flat foot, uh which is uh from birth. Whereas the flat foot, this one is an acquired flat foot because of an art rupture of your achilles tendon. When we look at ankle fractures and ankle joints, we are looking at the congruency of the tibia and the talus. And if you see that there is sunlight or the gap on the medial side is more than the gap on the superior side that suggests that either the fibula is fractured, lower down or up and the lateral strut that holds the ankle joint in place is rotated and displaced. So whatever happens to the ankle joint, uh you know, Weber B fracture affects the ankle joint. But also you can get a posterior malleus fracture. And this is associated frequently with uh delayed development of ankle joint, osteoarthritis when we are trying to approach these fractures or when we are trying to approach any bones in the body, uh especially in the lower limbs or anywhere in the body. Surgical approaches and anatomies are usually through the internervous planes. So, anatomy around the hip joint, when you approach for a hip replacement, you go through the internervous plan of superior and inferior gluteal nerves in between the uh gluteus medius muscle and the tensor fascia lata uh anteriorly. Or if you go posteriorly, you're trying to spare the sciatic supply to the posterior rotators in the knee joint. You are going to go through uh the muscle, uh the musculocutaneous junction between the vas the rectus femoris, as well as the vastus medialis to do a knee replacement in the ankle joint. Laterally, you'd have the peroneous muscles at the back and anteriorly, you'd have the tibialis anterior muscle to approach the lateral mallus. When we approach the posterior mallus and you go to the poster lateral part, you go between the peroneous muscle and the achilles tendon moving the neurovascular structure to one side. So all of them are through an internervous plane. So that if by accident, there is an aberrant nerve or an artery and one of them gets damaged, the entire function of the joint is not going to be lost because the other nerve and the other groups of muscles which uh go across the joint will continue with some of the function, albeit in a slightly uh uh weaker function. I don't think I have much more to say to you guys, this is what I have got for the moment and if that's OK, I would like to stop over here. Wonderful. If you press, stop sharing, I've pressed. Thank you so much. That was really great. And it was just good to see you focus on all the different regions in the lower limb and the relevance was really great. Um I'm gonna ask one more time if there's any questions. Um but if not, we will end there. Um Let me just ask the attendees um, if you any questions. Um whilst we just wait, see if there's any questions. Um, do you have any last er, kind of quick fire tips for learning lower anatomy? Um I think low limb anatomy, it is, it is one thing to learn from a book and I think book reading is always necessary, but I think when you read from the book, it is difficult to always grasp and remember Yeah. But when you look at it on a patient, you are more likely to remember. Hm. What tends to happen more frequently than or not is if an orthopedic surgeon is going to teach you, we get too focused on orthopedics rather than the things that you need at this stage. So when you are examining somebody as a junior doctor or when you're practicing for your exams, think about it in a different way when you're examining a joint, try and feel them, feel the groups of muscles try and feel the range of movement and try and see what the nuances are going to be. Most likely you are going to see them in clinical relevance. But I have no other way of saying repetition is the only way to remember anatomy. I remember my days of anatomy before uh many, many moons ago, last century to be more precise is, is when I would learn it, I would have rough paper and I would draw the anatomy and, and that would allow me to remember better because uh uh picture says 1000 words. Yeah. He had a lot more didactic anatomy teaching than the applied anatomy as you guys have because I think this is more relevant. Yeah, definitely. And I get out. So you've put everything together. So we don't have any questions. So we will end there. Uh Thank you for those who have attended. Um I know there are more people hoping to come today. So the recording will be made available afterwards. Um And you'll be able to catch up with all of the previous sessions. So far, we've had abdomen, upper limb, lower limb, and we'll be having some more um head and neck and some other uh focused anatomy sessions as well. So, thank you again, everybody and I will end the live session now. And thank you very much. Thank you very much, Alan. Thank you very.