now I want to switch a topic to uh how the wrist and hand uh typically work together so um the wrist um mostly will act or function as the St the stabilizer to afford uh finger movement and if you think about this way if if we want to grasp something um the finger flexors are uh the prime mover but the finger flexors are multi- joint that kind AC cross and the wrist and all the um digit joints uh digital joints then it's it's hard to get a full range of motion or um or um to have a good position for the shape to do so a lot of time uh we would need to rely on the wrist muscles so say uh if we want to bend our fingers then the wrist extensor will help to kind of counter so that the wrist don't uh don't go into flexion so that we don't have um sufficient muscle strength which is by the way is the active insufficiency so the wrist uh extensor is working to stabilize or keep um uh or immobilize uh but that's not a good way stabilize the wrist to allow the finger flexes to to to move so that's how um typically the wrist and hand muscles are working together about this so I just I just um talked about the active insufficiency here so imagine if um a a person who um has radial nerve pulsy or injury then the extensors are not working so that means the uh finger flexes has no counter Force when you know this person use the hand that means uh very likely this person will when the when the flexes are initiating um the this person will bend the wrists and then the fingers then and it's hard for this person to get a full range out of from this position right and especially when the wris in flection will um this person don't don't have a good strength for a grasping right so this is uh one example for uh the active insufficiency if we look at the other way so if when we bend the wrist the finger extensor I'm extrinsic finger extens uh extensors are being stretched to the maximum so that means uh it's uh there's tendency to bring the uh fingers into extension that will reduce the grip Force okay so um but uh clinically we often times take advantage of the passive inserv of the of the wrist in hand okay so and it's called U tenodesis so uh this is very uh helpful um grasp for especially for um individuals with spinal injury um especially C6 level so uh when a person who has spin cor injury C6 that they don't have uh finger extensors or intrinsic muscles right but they have R six sensors okay so what that means is they can um extend the wrist and then use that passive in insufficiency that U the finger flexes will be stretched and that will brings uh that will bring the uh fingers into flexion so that this person can you know have some kind of grasp okay and uh when this person need to re release this subject they can just ban the wrist uh the passive insufficiency of um the extensor um tendon will um help release the hand or open up a little bit of the hand so that this person can um release the uh the the object so you may you may think about um it can be really weak yes it can really weak um this T this is grasp and release so um when we work with uh individuals with spinal injury we want to enhance this tenal dises grasp and release because that's the only way that they can grasp and release on their own uh without any uh devices okay so we want to keep the the flexor tendon short because the shorter the finger flexor the greater the grasp um Force this person can can have but um if we intentionally uh short shorten the finger flexors we we want to make sure that the joint is okay so it's kind of hard to do because um you want this much person to move but not but not too much so here is the training uh that we typically do so uh we don't want to stretch the finger flexes because we want the flexes to be shortened right but we don't want the wrist or finger to have contracture or R of motion limitation so to move on the wrist we will bend all the finger uh and thumb and then move the wrist so that um we are moving the wrist without stretching the finger flexors so when we want to straighten out or prevent the stiff of the fingers we can bend the wrist and then kind of straighten out the fingers so that the flexor tendon is not in the um being stretched so in this way we can facilitate this person to use more on the Teno dises and uh when the factors got shorten um the power of the grasp will be greater so um this is um the recent hand function