Quadriceps femoris muscles 3D anatomy tutorial

in this video clip I will be discussing the quadricep femoris muscle group before we begin please review the osteology of the lower limb and also the movements permitted at the hip and knee joint there are four quadricep muscles which make up the quadricep femoris muscle group we have rectus femoris vastus lateralis vastus medialis and deep to rectus femoris there's another muscle called vastus intermedius these four muscles work together to produce extension of the knee joint here we can see it concentric Li contracting to produce extension and eccentric Li contracting to produce flexion if I move it to a more lateral view we can also see these movements in better detail a few examples of when we would use the quadriceps femoris muscle group would include when we're walking when you're performing a squat or when you're going from sitting to standing and a clinical example would be when we're testing the integrity of the femoral nerve which supplies all four of these muscles in the patellar tendon reflex when the patellar tendon reflex is performed the ligament which I'm pointing to here is tapped upon if the nerve which supplies all four of these muscles is working then the person would produce extension upon tapping upon the patellar ligament we'll take a look at the nerve which supplies all four of these muscles in more detail in a minute in this anterior view we can see the quadricep muscles here we have rectus femoris vastus lateralis vastus medialis and deep to these we have vastus intermedius I'm going to take a second and remove all of the other muscles in the thigh from this view so that we can take a better look in detail where these muscles attach onto the bones I'll begin by discussing rectus femoris here is rectus femoris highlighted it attaches to the anterior inferior iliac spine and goes down to the patellar tendon and attaches into the patella and by the patella down to the tibial tuberosity via the patellar ligament this muscle is sometimes referred to as the kicking muscle because it crosses not only the knee joint but also the hip joint so if you go to perform a kick you will be definitely using this muscle lateral to it we have vastus lateralis which is quite a large muscle fastest means big and lateralis means it's on the lateral side if I turn this and look at a lateral view or posterior view we can see that this particular muscle actually starts on the posterior aspect on the femur on the Linea aspera and also on the greater trochanter we can see the greater trochanter here this muscle also goes down and attaches into the patellar tendon attaches to the patella and then by the patella ligament down to the tibial tuberosity on the medial side of rectus femoris we have vastus medialis again vastus means big and medialis is referring to the fact it's on the medial side so again if I turn this model around we can see that vastus medialis also starts on the posterior aspect of the femur so it attaches onto the medial lip of the Linea aspera and also on to the intertrochanteric line which we can't see unless I take off rectus femoris here let me just take off rectus femoris and now we can see at its proximal end vastus medialis is attaching a little bit to the intertrochanteric line it goes down just like vastus medialis attaches into the patella and then down to the tibial tuberosity via the patellar ligament the last of the four muscles we can see here this is vastus intermedius so vastus intermedius is deep to rectus femoris it attaches to the anterior aspect of the femur it goes down and attaches into the patellar tendon which encompasses the patella and then via the patellar ligament down to the tibial tuberosity from this picture here we can see that these three muscles cross only the knee joint therefore they will only produce movement at the knee joint just like rectus femoris these four muscles produce extension at the knee joint when concentric Li contracting if we refer to the left limb here we can see the femoral nerve and I'm just going to zoom in a little bit so we can see this one in a bit more detail so here we have the femoral nerve it crosses underneath the inguinal ligament and once it reaches the anterior thigh it spreads out and supplies all four of these muscles at the end of this video clip press pause and try answering the following four questions we'll review these four muscles in more detail in class

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