besides getting his kids dressed and dropping them off at school, jason coburn must get himself ready. that means making important decisions about what he is going to be wearing today. >> being a bilateral amputee, you have to use prosthetics. if you are a single-arm amp tea, you have the ability to use a real hand to help, you know, it's kind of like a tool for them. >> near san diego, california, katie walker is putting her newest tool. this para olympic hopeful is trying out prosthetics field. >> the difference is the little wrist unit. it actually pops off. >> all right. >> and actually, the handle goes right inside of here. so, it's supposed to, after i swing, after i follow through, you just pop it right off. >> then run? >> then start running. >> and rotate around. cool. >> for upper-limb amputease, gone are the days of hook and cable arms. in labs like this one at advanced arm dynamics outside dallas, texas. technicians work alongside therapists to custom design dreams. >> really cool to have an opportunity to see a patient, see what they need and actually do what they need, n