 In this video I will describe the general structure of the following joints, focusing on the range of movement. The glenohumeral joint, commonly known as the shoulder joint. The humeral ulnar joint, commonly known as the elbow joint. The proximal radio ulnar joint, which is joint located in the antibrakeal region, which enables supination and pronation. The radiocarpal joint, commonly known as the wrist joint. The acetabulofemoral joint, commonly known as the hip joint. The tibiofemoral joint, commonly known as the knee joint. And the talocural joint, commonly known as the ankle joint. Here we see the structure of the glenohumeral joint. See that the head of the humerus articulates with the glenoid cavity in order to form the glenohumeral joint. This joint is a ball and socket joint that enables a wide range of motions, including rotation, you can have medial rotation or lateral rotation of the humerus at the glenohumeral joint. It allows afflection and extension, and also allows abduction and adduction. The glenohumeral joint is a joint that has a wide range of movement and is very flexible. However, in turn for that flexibility, there is a trade-off that the glenohumeral joint is less stable. The glenohumeral cavity is not a very deep socket, it's a relatively shallow socket. And so this enables a large amount of flexibility, but not a large amount of stability in the glenohumeral joint is commonly dislocated. However, there are ligaments and tendons to help stabilize the glenohumeral joint. So we can see here the tendons of some of these muscles. Here the tendon of the supraspinatus is a muscle in the rotator cuff group of muscles. There are four rotator cuff muscles that have their tendons crossing the glenohumeral joint and help to stabilize the glenohumeral joint. Here we see the humeral ulnar joint, commonly known as the elbow joint, where the trochlea of the humerus articulates with the trochlear notch of the ulna. This is a hinge joint, subcategory of synovial joints that enables flexion and extension, but only flexion and extension. And so the trochlear notch fits tightly around the trochlea of the humerus and that very tight bone-to-bone fit restricts motion. So there's only motion of flexion and extension enabled at the humeral ulnar joint, and this joint is then further stabilized by strong ligaments, as well as several muscle tendons that cross the humeral ulnar joint. We can see in this illustration the tendon of the triceps brachii muscle is crossing the humeral ulnar joint from the posterior, and the tendon of the brachialis muscle crosses the humeral ulnar joint on the anterior. So those are muscles that will help to stabilize the humeral ulnar joint. The proximal radial ulnar joint is the articulation between the head of the radius that we can see here, so the head of the radius is stabilized by the annular ligament that helps to hold the head of the radius onto the radial notch of the ulna. And the radius will pivot as it moves, so the proximal radial ulnar joint is an example of a pivot joint that enables the actions of supination and pronation. So supination and pronation are the actions of pivoting the proximal radial ulnar joint. Starting in anatomical position, the proximal radial ulnar joint is in the supinated position. And then a medial rotation is pronation of the proximal radial ulnar joint that would then move the palm to face backwards. The radiocarpal joint is the joint commonly referred to as the wrist joint. The radiocarpal joint is a condyloid joint. A condyloid joint enables motion through two planes, and so the radiocarpal joint enables flexion and extension, and also enables abduction, abduction, and abduction. So when you're moving the radiocarpal joint, when you're moving the wrist, the manual region, the hand is moving relative to the anti-brachial region, forearm, and you can flex the radiocarpal joint to move the palmar region superiorly and anteriorly through the sagittal plane, or you can extend the radiocarpal joint to return to anatomical position, or you can abduct the radiocarpal joint to draw the manual region laterally, or you can adduct to move the manual region back towards anatomical position. So here's another view of the radiocarpal joint where we can see the articulating bones. The radius is articulating with the most proximal row of carpal bones, the scaphoid on the lateral side, and then as we move medially you can see the lunate is the other bone that has the majority of the articulating surface with the radius, and the triquetrum and pisa form are off to the medial side, but they rarely contact the ulna, and so it's primarily the joint between the radius, the scaphoid, and the lunate that forms this radiocarpal joint. And the joint is cushioned with an articular disc, this is a disc of cartilage that's located between the head of the ulna and the triquetrum and pisa form. The acetabular femoral joint is commonly referred to as the hip joint where the head of the femur articulates with the acetabulum of the coxal bone. The acetabulum is a deeper socket than the glenoid cavity and enabling a more stable articulation so that the acetabular femoral joint is much less commonly dislocated than the gleno-humoral joint. But there are also ligaments to help stabilize the acetabular femoral joint including the ligament of the head of the femur that attaches to the fovea on the head of the femur and helps to anchor the head of the femur into the acetabulum, and then there are extra capsular ligaments as well surrounding the acetabular femoral joint. And the acetabular labrum is a lip of cartilage that makes the socket of the acetabulum even a little deeper to fit the head of the femur with more stability. So here we can see the extra capsular ligaments that are strong ligaments which help to stabilize the acetabular femoral joint. So as a ball and socket joint the acetabular femoral joint can perform a wide range of actions including a motion of rotation lateral rotation and medial rotation as well as flexion and extension abduction and abduction when the acetabular femoral joint is in the fully extended position when you're standing up in anatomical position the extra capsular ligaments such as the iliofemoral ligament and pubofemoral ligament that we can see here as well as the ischiofemoral ligament around on the posterior side out of a few. These ligaments pull the head of the femur further into the acetabulum when the acetabular femoral joint is extended and so this will help to further reinforce and strengthen the acetabular femoral joint when we're standing up and there's more weight being supported by this joint. The acetabular femoral joint is a joint that is commonly damaged by the wear and tear of motion over time with age and eventually the the articular cartilage can become damaged. This leads to a condition known as osteoarthritis so osteoarthritis will will cause pain in that joint can lead to inflammation and swelling as the immune system responds to the irritation of the tissue as and the exposed bone becomes damaged and can start to to further produce scarring or growths that will lead to restricted motion over time and so the acetabular femoral or hip joint is one of the joints that's more commonly replaced as it as a treatment for osteoarthritis when the the damage to the articular surface becomes severe so a acetabular femoral joint or hip joint replacement can be done by by adding in an artificial femoral head and an acetabulum in order to to replace the articulating surfaces that have been damaged. So here we see the tibiofemoral joint which is another example of a hinge joint. So tibiofemoral joint commonly known as the knee joint is a hinge which enables flexion as well as extension the tibiofemoral joint is a relatively unstable joint as a result of a poor bone-to-bone fit between the condyles of the femur and the condyles of the tibia. However there are lots of muscle tendons and ligaments that can help to reinforce the tibiofemoral joint. Here we see the extracapsular ligaments the lateral collateral ligament and fibular. So lateral collateral is a synonym for fibular collateral ligament. So lateral collateral or fibular collateral ligament and then on the medial side we have the medial collateral or tibial collateral ligament. So the tibio collateral ligament and fibular collateral ligament are extracapsular ligaments located superficial to the joint capsule that help to stabilize the tibiofemoral joint and then we can see there are the tendons of the quadriceps femoris muscle here on the anterior. So the tendon of the quadriceps femoris muscle attaches to the patella and the patella ligament continues from the patella down to the tibial tuberosity in order to provide attachment enabling the quadriceps femoris muscle to have its action as it pulls on the patella the patella ligament will then pull on the tibial tuberosity enabling that action to extend the tibiofemoral joint. And so here we have a deep view of the tibiofemoral joint where we can see the intracapsular ligaments the posterior cruciate ligament as well as the anterior cruciate ligament. These ligaments deep within the joint capsule help to stabilize the tibiofemoral joint and then to further help stabilize the joint there are meniscus meniscus menisci. There's a lateral meniscus that we can see in this illustration so there's the lateral meniscus but there's also a medial meniscus just out of view in this illustration so the lateral meniscus sits superior to the lateral condyle of the tibia and helps contour around the surface of the lateral femoral condyle similarly the the medial meniscus is located on the superior surface of the medial condyle of the tibia and these meniscus have a curved C shape that helps to contour around the curved femoral condyles enabling this hinge joint to be more stable while maintaining its its mobility. And so here we have a superior view of the tibial surface of the tibiofemoral joint where the medial meniscus is located on the medial condyle and the lateral meniscus is located on the lateral condyle and you can see how this C shape creates a contoured surface for the curved femoral condyles to sit in and then the anterior cruciate ligament attaches to the femur from the anterior of the tibia and it crosses horizontally it crosses diagonally where the posterior cruciate ligament is moving up in the opposite direction from the posterior to attach to the femur and so that's why these are called cruciate ligaments cruciate means cross and the anterior cruciate ligament crosses anterior to the posterior cruciate ligament and those ligaments help to stabilize the tibiofemoral joint common injury to the tibiofemoral joint resulting from a a force that hits the lateral aspect of the of the knee of the tibiofemoral joint this could be a common sports injury for example if someone was playing football and got tackled at the knee from the lateral side this could cause this type of injury and the the injury which is commonly just referred to as a blown knee is a triad of three different injuries the anterior cruciate ligament becomes torn similarly the tibial collateral ligament or medial collateral ligament becomes torn and and also the medial meniscus can become can become damaged and so that that is what's classically referred to as the the triad of a of a blown knee however it it is possible to have injury to the lateral collateral ligament or lateral meniscus or posterior cruciate ligament anterior cruciate ligament damages is relatively common and it may be seen with a lateral meniscus or a medial meniscus tear or a a lateral collateral ligament or a medial collateral ligament tear so the last joint that we'll go through is the tallow curl joint so tallow curl joint is commonly known as the ankle joint that this is the joint between the talus the most superior of the tarsal bones and the distal ends of the tibia and fibula so it's it's primarily the tibia that articulates with the talus the tibia is the weight-bearing bone in the curl region and the the fibula on the lateral side helps to stabilize the tallow curl joint the tallow curl joint is a hinge joint so it enables flexion and extension actions and at the tallow curl joint we specifically called these actions dorsiflexion dorsiflexion to draw superiorly and plantar flexion is the opposite