hi everybody dr mark here in this video we're going to go through joint movements now the first thing we need to start off with is that different types of joints in the body have different degrees of freedom when it comes to their joint motion and there's only three axes in which a joint can move in if a joint moves in one axis it's called uniaxial if it's two axes it's called biaxial and if it's three it's multi-axial and the different gross movements that a joint can perform have different names which have written up on the board and we're going to go through them one by one but before we begin you need to understand something called the anatomical position because when we refer to each of these types of joint movements we always have the anatomical position in mind and this is the anatomical position we've got feet shoulder width apart eyes facing forward arms by the side palms facing forward as well like this this is the anatomical position keep that in mind as we go through these particular types of joint movement abduction abduction is the first one what does it mean if somebody has been abducted it means they've been taken away that's all abduction means it means take away from the body or take away from the midline of the body so abduction of the arm abduction of the leg that's abduction you can also have abduction of the fingers again anatomical position abduction of the fingers then when we look at adduction this is bringing back toward the body back toward the midline so you can have adduction of the arm you can have adduction of the leg and you can have adduction of the fingers again when we look at the next point flexion generally speaking when we say flexion we're referring about decreasing or minimizing the joint angle that's what we're usually referring to when it comes to flexion so if we use this definition you can have flexion at the shoulder joint flexion at the elbow joint flexion at the hip joint and flexion at the knee joint now you may ask what about flexion at the ankle this is where it gets a bit iffy because the true biomechanical definition of flexion is the approximation of ventral surfaces across a transverse axis and you may be thinking what does that mean it's a ridiculous definition but what we highlight there is ventral surfaces and when we look at the foot the dorsal aspect of the foot is actually the top of the foot so when you flex that foot to minimize that angle in actual fact you could define that as extension in a strange way if we go by the biomechanical definition so we don't use flexion and extension per se when we look at the foot what we use is dorsiflexion and plantar flexion and so dorsiflexion is where we bring that foot or the toes up towards the top of the body that's dorsiflexion pointing the toes upwards and plantar flexion is pointing the toes down towards the ground the way i remember that is if you're planting something in the ground plantar flexion pointing the toes down towards the ground plantar flexion all right then we can look at extension so again generally extension is increasing or maximizing the angle at the joint so let's go through those joints again we've got shoulder extension we've got elbow extension we've got hip extension and we've got knee extension you can see that i've put the the prefix hyper there so you can have hyper flexion and hyper extension and this is simply highlighting the fact that when you flex beyond that joint angle and when you extend beyond that joint angle that's what referring to is hyperflexion and hyperextension respectively now circumduction this is moving the joint in a circle around its axis so usually what we're talking about here are ball on socket joints right so the hip and shoulder predominantly when we look at the shoulder right circumduction moving around in a circle circumduction for the hip moving around in a circle really important now you may be thinking how is circumduction different to rotation the difference is circumduction is in a circle rotation isn't necessarily in a circle it's just moving within the confines of that axial plane so circumduction if you were to put a pen at the joint and put it on a piece of paper it would draw a circle with rotation if you were to put a pen at the joint it would just draw a dot or a line and so the different types of rotation you can have for example are internal rotation so think about the shoulder you can have internal rotation you can have external rotation you can have internal external rotation at the hip as well so you've got internal rotation external rotation then we've got inversion and eversion so this can sometimes be confused particularly when we're referring to the foot inversion e version pronation supination it's a bit tricky and difficult if we refer to the foot to begin with inversion is where the foot is pointing inward in version so inversion eversion is putting the weight on the outside of the foot so inversion putting the weight on the inside of the foot e version putting the weight on the outside of the foot pronation and supination is where for example you've got the palms or your forearms facing upward that's supination pronation facing downward and you can think about this when we refer to a patient as well if they're laying prone they're going to be on their back if they're laying supine they're going if they're laying prone they're going to be on their front sorry if they're supine they're going to be on their back the way i remember this is supination soup if you wanted some soup you have palms upwards right soup supination pronation so this is a really quick run through of the different types of joint movements