Design and manufacturing of shin pads with multi-material additive manufactured features for football players: A comparison with commercial shin pads

Shin pads are part of the mandatory equipment footballers must wear so as to prevent lesions. Most players wear commercially available shin pads made from a variety of common materials (polypropylene or polyethylene) and high-resistance materials (glass fibre, carbon fibre or Kevlar) using traditional manufacturing techniques. Additive manufacturing was used years ago to deliver customised rigid shin pads, but they did not offer any significant advantage in terms of materials or design compared to traditional shin pads. This project analyses a novel approach to the design and manufacture of shin pads for football players that combines existing digitisation tools, lattice structures and a multi-material additive manufacturing device. A total of 24 different additive manufacturing geometries were evaluated using a customised rig where a 1-kg impactor was released from several heights (100–400 mm). The impact acceleration, the transmitted force to the leg and penetration were calculated. Results were compared against two commercially available shin pads. Results show that two of the additive manufacturing specimens tested at the highest drop height had lower impact accelerations than commercial shin pads. They had an acceleration reduction between 42% and 68% with respect to the commercial shin pads. Regarding the penetration, the improvement achieved with additive manufacturing specimens ranged from 13% to 32%, while the attenuation and the contact times were similar.