 I'm Dr. Sanjay Sanyal, Professor and Department Chair of Anatical Sciences and the Gavron persons as Sahiya, Jenny Glover, Zalika Stewart and a few other people, so there are too many of them around. Okay, so our first part of the discussion I'm going to demonstrate the anterior and the lateral compartment of the leg and then I'm going to mention a few other points. So we have reflected the skin from the anterior and the lateral side of the leg and the first thing that we see here is this tough fascia here. This is the trural fascia. We have seated open on one side here and this is the other side of the trural fascia and it's been split open. So let's reflect the trural fascia. As you can see on the medial side of the tibia, the fascia was densely adherent to the skin and to the bone and this portion of the tibia is subcutaneous. I'm showing the same video clip from the opposite side to show you the fact that this portion of the tibia is subcutaneous and because of this reason any tibial fracture tends to get compound either from within or from without. That means it penetrates through the skin and that adds to the complications of tibial fractures apart from the other problems which we have with tibial fractures. We are focusing on the anterior and the lateral compartment. So let's reflect the trural fascia from the anterior compartment of the leg and this is what we have done. And once we do that we see the anterior compartment. So what do we see here? Straight away we see this tendon here, the thick large tendon which is getting inserted onto the torso bone here and this is the tibialis anterior. This is the most powerful dorsiflexor of the foot and paralysis of this muscle of the anterior compartment will lead to foot drop as I mentioned to you earlier. This is the tibialis anterior. The next that you see here is the extensor halosus lumbus tendon and once this group of tendons that we see after that this are the extensor digitorum lumbus tendon and the fibularis tertius is situated in a small tendon on the lateral aspect of that. Having mentioned that I need to point out to you that all of these are running under two retinicula. There is one superior extensor retiniculum which I have removed which is here which is the thickening of the trural fascia and there is a stronger inferior extensor retiniculum where my probe is partially gone through. So all these tendons are running under the inferior extensor retinicula. I will tell you the details of the extensor retiniculum when I come to the ankle joint and the foot. Having mentioned these tendons now let me show you the neurovascular structures. The neurovascular structures are shown here. I have lifted them up here and you can see this is the deep fibular nerve. This is the deep fibular nerve which supplies all the muscles to the anterior compartment and this is the anterior tibial vessel and if you feel it you will feel that it's got a thick wall here and in here it is slightly corrugated. I think it's suffering from arteriosclerosis. What I would like you to notice is that these neurovascular structures are also going deep to the extensor retinicula and it is here that the deep fibular nerve can get entrapped and what we call as the ski boots syndrome, entrapment of the deep fibular nerve here. After the deep fibular nerve has supplied all the muscles to the anterior compartment it goes to the muscle on the dorsum of the foot and here it supplies some superficial muscles on the dorsum of the foot and then it becomes cutaneous and supplies only the first inter-digital cleft which I mentioned in the class. So that's about that. On the other hand the anterior tibial artery it also goes under the extensor reticulum and on the foot it divides into its two terminal branches. One of them is the dorsalis pedis and the other is the lateral tarsal and the dorsalis pedis is the one which we feel clinically just lateral to the tendon of the extensor halosus longus and that is clinically palpable as the dorsalis pedis pulsation. So that is about the muscles and structures of the anterior compartment. I have rifted up the clural fascia and I am showing you this video clip from the opposite side to tell you about a very important condition. These muscles in the anterior compartment they are enclosed in a tight osteofacial compartment composed of the bone, the introsius membrane and the clural fascia. Therefore if there is an excessive usage of the muscles of the anterior compartment especially in the TBRS anterior or if there is a trauma then it leads to swelling of the muscles of the anterior compartment and that condition is known as shin split and if this condition is allowed to progress it can lead to excessive swelling of the muscle and can lead to compromise the neurovascular structures in the anterior compartment and lead to even gagrene. Therefore the treatment for this condition anterior compartment syndrome is to do essentially what we have done in this dissection and that is to split open the deep crural fascia the crural fascia the condition the surgical condition being called fasciotomy and that is this. Now let's do something this is again the crural fascia which I am putting it back the crural fascia was continuing behind and so what I have done is I have slitted open to show you the muscles of the lateral compartment and let's because it's rather deep inside so what I will have to do is I will have to turn the leg so you have to come under this to have a look. This is the lateral compartment and I have slit open the lateral part of the crural fascia to show you the fibularis longus and the fibularis brevis so this tendon and the muscle that you see the muscle fibularis longus is the one which is taking origin from higher up in the fibular and the fibularis brevis is the one which takes origin from the lower part so this is the fibularis longus tendon and this is the fibularis brevis tendon and if you want to trace both of them the fibularis longus and the fibularis brevis tendon both of them are running behind the lateral malleolus. And the fibularis brevis gets inserted onto the tuberosity of the fifth metatarsal where the fibularis longus goes behind that and goes under the foot and it gets inserted onto the medial side of the foot. That's all we can see in the lateral compartment because the superficial fibular nerve as it winds around the head of the fibula which is here, it immediately divides into a deep fibular nerve which runs in the anterior compartment and the superficial fibular nerve which supplies the muscles here and it becomes cutaneous in this region therefore we cannot see the superficial fibular nerve here. So these are the structures which I wanted to show you in the anterior and the lateral compartment. I'm recording the same video of the lateral compartment from another perspective to mention a few extra points about the longus and the brevis, fibularis longus and the brevis. The fibularis longus originating from higher up on the fibula and winding around the lateral malulus gets inserted, it goes deep to the sole of the foot and it gets inserted onto the medial side of the foot onto the first metatarsal and medial cuneiform and here it helps to maintain the transverse arch of the foot. On the other hand the fibularis brevis, it gets inserted onto the tuberosity of the fifth metatarsal and when there is a forcible contraction of this brevis it can lead to aversion fracture of the tuberosity of the fifth metatarsal which is known as the Dancer's Fracture. Thank you very much for watching, have a nice day.