 So this is going to be demonstration of the quadriceps the muscles the tendon and there's some clinical correlations Let's move this sartorius out of the way to show the quadriceps the quadriceps has got four Components the first muscle of the quadriceps to this one, which we have picked up here This is the rectus femoris as the term implies. It's a straight muscle. That's why it's called rectus It's got two origins. One origin is from the anterior Inferior iliac spine where my hand is disappeared That's a direct head and there's a reflected head deep to that which takes origin from the acetabular margin And this is the main muscle mass which continues down and gets inserted onto the quadriceps tendon Which we can see here. I will describe the quadriceps tendon separately It is a two joint muscle. It's crossing the hip joint and it's crossing the knee joint So therefore a footballer before he launches his kick He first extends his hip and flexes his knee and from that position when he kicks his hip flexes And his knee extends and that action is performed by the quadriceps Therefore quadriceps is considered as the kicking muscle loss of functional the quadriceps is equal into loss of function of the quadriceps As a whole by 17% now my assistant has retracted the rectus femoris out of the way And we are going to demonstrate the other components of the quadriceps the muscle Which we see immediately under the quadriceps this one here and my finger is tracing it here This muscle that we see right in the front of the femur this one This is the vastus intermedius takes origin from the front of the femur and the tendon then gets inserted onto the quadriceps tendon again The next muscle is on the lateral aspect and we can see this muscle here, which I have lifted up This is the largest of the quadriceps and this is the vastus lateralis This takes origin from the lateral lip of the linea aspera where my hand has disappeared because it's in the posterior aspect of the femur and When it is coming forward it is covered by the iliotibial tract on its lateral aspect And it is covered by the posterior intervascular septum on its posterior aspect So this is the vastus lateralis and these fibers then Come immediately and they also get inserted onto the quadriceps tendon That's the third component and the fourth component of the quadriceps is this muscle here This muscle, this is the vastus medialis This takes origin from the medial lip of the linea aspera and the fibers then converge and they get inserted onto the quadriceps tendon So these are the four components of the quadriceps muscle inserting onto the tendon the quadriceps is the most powerful extension of the knee and It is three times as powerful as its antagonist namely the hamstrings, which are flexors of the knee Let's start with the quadriceps tendon. Quadriceps is a very powerful tendon Where all the four muscles get attached inserted and we can see the quadriceps tendon in front of us The quadriceps tendon gets inserted onto the base of the patella, which is on the upper part of the patella And the apex of the patella is down below here Apart from the common Insertion to the quadriceps tendon each muscle has got their own separate attachments to the patella the rectus femoris Vastus medialis Vastus intermedius and Vastus lateralis also gets independent attachments to the patella Yet one more Attachment which is unique only to Vastus medialis is these fibers that we can see if we look at them very carefully We will see that the fibers are running obliquely and parallel and they're very finely hatched These are the medial patella retina gulam which are an aponeurotic expansion given by the Vastus medialis Likewise, if you look from the lateral aspect, we can see these parallel hatched fibers which form an aponeurotic expansion This is coming from the Vastus lateralis So the Vastus lateralis and the Vastus medialis both of them give these aponeurotic expansions which are respectively referred to as the lateral and the medial patella retina gulam These are attached to the sides of the patella and they get inserted onto the margin anterior margin of the tbl Condyle and they reinforce the anterior capsule of the knee joint and they also help to stabilize the patella apart from this insertion yet we can notice that from the quadriceps tendon and thin aponeurotic sheet goes above the patella which we have lifted up and it goes down towards the knee and Thereafter we notice that from the apex of the patella We can see one tough ligamentous structure where my finger is tracing This is the ligamentum patellae or the patella ligament which extends from the apex of the patella All the way down to the tbl tuberosity So this is the final insertion of the quadriceps and therefore we can say that the patella is like a Cessamoid bone within the composite tendon of the quadriceps which extends from above the patella and Down to the tbl tuberosity with the Cessamoid bone of the patella inserted in between The function of the patella is to alter the direction of pull increase the mechanical advantage and therefore give power To the extension of the knee now we are demonstrating the nerve supply of the quadriceps We are picked at the main trunk of femoral nerve The femoral nerve has got a very short trunk as it emerges from under the inguinal ligament And thereafter immediately it divides into multiple branches It divides many into many cutaneous But most of the branches are muscular branches and we can see the muscular branches Supplying each and every component of the quadriceps We can see branches to the rectus femoris. We can see branches coming to the Vastus medialis Vastus intermedius and we can see branches going to the Vastus lateralis I would like you to notice that apart from all these muscular branches to the muscles of the anterior compartment there are two Nerves which are running very close to each other The lateral one this is the muscular branch to the Vastus medialis and we can see that here And this is the one which is the sensory branch This is the largest cutaneous branch of the in the body and it's a branch of the femoral nerve Which goes outside the thigh into the leg This is known as the syphilis nerve And this runs Initially in the erector canal And then it passes out of the erector canal and we have traced it out And then we can see it runs in accompaniment with the long syphilis vein And it matches the course of the long syphilis vein on the medial side of the leg All the way to the medial side of the foot. So this is one of the cutaneous branches of the femoral nerve And while we're on this topic I would also like to add that the femoral nerve also gives Another cutaneous branch and we have picked that up here. This is the anterior femoral cutaneous nerve This pierces the deep fascia and it supplies a large part of the front of the thigh So these are the cutaneous supply of the femoral nerve So this is the nerve supply the femoral nerve, which is l 234 posterior division of the lumbar places So that brings me to a very important series of clinical correlations pertaining to the quadriceps tendon If there's any due to the femoral nerve, then obviously this muscle gets paralyzed Apart from the fact that the person will not be able to extend his knee When the person tries to walk The knee will flex because of the unopposed contraction of the hamstrings And therefore the patient develops a very unique posture when walking with the paralyzed quadriceps He holds his quadriceps muscle Just above his knee the way I am holding And by so doing he helps to keep it honey straight So therefore when you see a person walking Holding just above his knee that means he has about either quadriceps weakness or he's got quadriceps paralysis So that is one important manifestations of quadriceps paralysis The next important point which I want to mention is about the quadriceps reflex So let me show you the peddler tendon This is the peddler tendon Extending from the apex of the peddler to the tibial tuberosity. This is a very useful test which is done in clinical practice We ask the patient to sit comfortably and cross one leg We feel for the apex of the peddler And we feel for the tibial tuberosity and in between the slightly depressed soft portion is the Legamental peddler and we can see it here. And this is exactly where we strike with the knee hammer It's a stretch reflex or a myodontic reflex Where the knee extends and this is a very useful test for demonstrating upper motor neuron lesions in central nervous system So this is another important clinical test That brings me to quadriceps exercises and quadriceps testing The two are slightly different though. They may appear similar quadriceps testing is done By asking the patient to keep the knee semi flexed And then we ask the patient to extend the knee against resistance and we provide resistance on the leg And we feel the contraction of the quadriceps just above the knee That is how we test for the quadriceps In contrast quadriceps exercises is something which is prescribed to people who have chronic knee pains And by strengthening the quadriceps It helps to alleviate the knee problems to a certain extent though not completely Quadriceps exercises is to be done regularly at least twice a day for 10 minutes each The patient is supposed to sit flat on the bed Put one hand under the knee the way I have done And ask the person to Contract the quadriceps and press down on his own hand. This is an isometric exercise. And this is called quadriceps exercises So this is a useful method to keep the problems at bay So these are some important critical correlations pertaining to the quadriceps Thank you very much for watching. If you have any questions or comments, please put them in the comment section below Dr. Sanjay Sanyal signing out. Have a nice day