1. Crutches hit road at an acute angle, so often skids.
2. Cause rapid wear to rubber tips.
3. Severe impacts are transmitted to upper limb joints causing multiple injuries.
4. Standard crutches rapidly suffer structural failure.
Crutches were modified by having tungsten carbide points projected through rubber tips, preventing skidding and accelerated wear. Telescopic gas springs with hydraulic shock absorption were fitted. Memory foam was fitted to hand grips spreading the load over the palm area. All metal joints welded.
The marathon was completed without injury in 8 hours 17 minutes.