Next generation sprint spikes developed at Loughborough University could be key to
Design and manufacture of sole units for research
Sole units were designed by first taking 3D digital scans of individuals' feet. The scans were imported into Solid Works CAD software and various designs created including designs to achieve varying bending stiffness. Sole units (aka spike plates) were manufactured at the University using the Selective Laser Sintering (SLS®) process using a Vanguard machine supplied by 3D Systems Inc. SLS® works by taking a 3D CAD model of a product, slicing into 0.1mm slices and manufacturing each slice one, by one using a laser to melt together plastic particles - this effectively "prints" 3D objects allowing low costs for low volumes and one-offs and giving designers freedom beyond that afforded by other manufacturing processes. The material used was Duraform™, a Nylon 12 based thermoplastic also supplied by 3D Systems Inc. Standard sprint shoes uppers supplied by New Balance Athletic Shoes were attached to the Duraform™ sole units at the New Balance Factory in Flimby UK.
Testing of sprint spikes
Sprint spikes with SLS® sole units were benchmarked against a range of spikes purchased by UK Sports and supplied by various manufacturers using a number of existing (e.g. ASTM F911-85) and specially developed mechanical testing methods at Loughborough University and at TNO Industries (Eindhoven). The spikes with SLS® sole units were found to generally have bending stiffness spanning the mid to high range of stiffness from the rage of sprint spikes tested. Some of the spikes with SLS® sole units were found to have higher bending stiffness than any other spikes tested.
- TNO Industries (Netherlands)
Athlete testing in the lab
A variety of lab tests were performed with a number of elite athletes at Loughborough. A number of standard tests (squat jumps and bounce drop jumps) were used and developed to allow repeatable measurement of performance using sole units of different stiffness. During these tests a variety of specialised equipment was used including Vicon 3D motion analysis (recording at 480Hz), and a Kistler force plate (recording at up to 1000Hz).
Athlete testing on the track
The influence of sprint spikes on bending angles in the foot were measured at different stages of a 100m sprint (10m and 50m) using High speed Digital Video (capturing 1000 frames per second). Angles were measured using strategically placed markers on spikes and on bare feet at Loughborough University's High Performance Athletics Centre. The results helped the researchers to quantify the effects of spikes on kinematics in the foot during sprinting.