Discus-thrower Derek Derenalagi competes using a custom frame that's specially designed to meet strict rules for Paralympic athletics, which state that any equipment can be used so long as he can get set up and ready to compete within 60 seconds.
"Derek wanted to use his prosthetic legs while competing but didn't know how or where to place them with his previous equipment" says Roger Thorn, an engineer and volunteer for charity Remap that makes custom-built equipment for people with disabilities.
After a consultation with Derenalagi and his coach at their training centre, Thorn developed the discus-throwing frame to suit the athlete's exact requirements.
Replacing a heavy steel stool that restricted movement and provided little comfort, the new frame allows Derenalagi to make adjustments in height, seat pitch and shoe positioning to find the most comfortable and effective throwing position.
The new frame is made from lightweight box aluminium designed to withstand the force created during the throw and is lightweight so it can be transported to competition venues. It is secured to the ground with four adjustable straps and Derenalagi is strapped to it with two seat belts.
Derenalagi threw 39.37 metres to come 11th in the final of the F57/58 discus event, held at the Olympic Stadium on 31 August.
See custom equipment for "blade runner" Oscar Pistorius we've featured here and all our stories about design for Paralympic athletes here.