This is a photo of Chuck's first knee joint made by "Otto Bock". It is attached to the adjustable Velcro socket suspension system below. Very simple but it gets the job done.
Chuck's first socket (decals extra) adjusted for stump size by means of velcro straps. Nice but you have to wear a belt to hold it on. There is always a certain amount of "pistoning", meaning that the leg starts to come off slightly when you take a step.