all right so in this feed we look at the different types of synovial joints there are actually six different types of synovial joints and there are they're categorized based on the shape of the articular surface you know like whether it's a plain surface whether it's condylar or Balan Saket or saddle shaped and as well as the type of movement that joint is capable of so the first one we'll talk about is the plane joint we've discussed this earlier as one of the non axial types of movement because it's more of just a slipping motion across flat articular surfaces like in your carpals met your tarsals as well as the articular surfaces of your vertebrae and so because of the slipping surface we think of this as being a plane where they basically just can slide across each other so these plane joints are really good at sliding movements or gliding movements rather so if you move your wrist back and forth you know the carpals are gonna slide and glide against each other but in a non axial way now the hinge joint is actually shaped like a hinge and it's where you basically have a cylinder within a trough and so this would be the cylinder shape here if the trochlea of your humerus this would be the trough which is the trochlear notch of your ol nough and together they make this elbow joint now if you think about like how the elbow joint can move it can rock back and forth within one plane so we think about this as being uniaxial because it can move along one plane and that plane would basically be the sagittal plane because you can flex and extend along that plane now the interphalangeal joints are between your fingers are also considered a hinge joint because they have this particular hinge like structure now a pivot joint is pretty fascinating one example of this is where you find the ulna and radius articulate at the proximal end where the head of the radius can actually rotate around the ulna and what's pretty cool then is that the have the radius actually encased in this little ligament and what's what's neat then is a sleeve of bone surrounds the radius and basically this axle moves now in this example it's not a bonus is a ligament but an example of where you'd find a bone here would be like the you know the the the Atlas and where they articulated now this rotational movement is going to move in one axis as well and this axis is going to be just along the longitudinal axis of this particular you know bone so we think about this is going to aid in the rotational movements like supination and pronation so as your forearm supination pronate the head of the radius can rotate within a sleeve in order to move your whole forearm now to example of a condor lower joint is going to be like the metacarpal phalangeal joints like where the metacarpals meet the phalanges and it's called a condylar joint because you have an oval articular surface that one's concave and one's convex and they kind of fit into each other now this is considered biaxial because you can move in many different directions here or multiple directions rather and this condyle is going to be fairly stable due to the shape of these bones so other examples of where you find condylar joints would be like your wrist joint or the metacarpal phalangeal or basically these are the knuckle joints now an example of a saddle joint where actually looks like someone sitting in a saddle here is we have convex and concave surfaces that kind of interlock against each other an example of where you'd find this would be the carpeaux metacarpal joint of your thumb and so this allows your thumb to move in a biaxial motion right front back and side to side and so it allows for an abduction in abduction as well as flexion and extension of the thumb at the level of the the carpals here so it's pretty neat now the ball and socket is basically what sounds like you have a ball and it sits in a socket and one example this is going to be the shoulder joint or also the glenohumeral joint as well as your hip joint and in both these cases you have a ball shaped head of either the humerus of the femur that sits in a cup shaped or socket shaped other bone whether it's your scapula or your pelvis now this is gonna allow for the most movement it's actually multiaxial so it's the most movable joint because you can move along all three different planes it can rotate it can AB duct in a duct and flex and extend so this is gonna be capable of things like circumduction which use a mixture of all three of these types of motion now if this is a multiaxial type of joint this also means that this joint is one of the least stable and that RIT that fits our rule in terms of the trade-off between mobility and stability we're highly mobile joints are absolutely stable in fact your shoulder joint is one of the most commonly dislocated joints in the body because of the fact that it's so movable and there's really not a whole lot holding this on other than some muscles and supporting ligaments