This project aimed to design, develop, and test a prosthetic terminal device that allows children with UL differences to safely use monkey bars.

The device was developed following a user-centred design process, guided by interviews, a Product Specification Document (PSD) and iterative prototyping. A dual-material design incorporating Polyethylene Terephthalate Glycol (PETG) and neoprene was used to ensure strength and secure grip on varying bar diameters. Finite Element Analysis (FEA) and physical tensile testing verified structural integrity under a 1235 N load. A final 130º grip angle was selected based on proxy-user testing.

The device was shown to support forces 34% above the design load with a safety factor greater than 3 and a calculated fatigue resistance for more than 25,000 cycles. It securely gripped bars from 31.75–38 mm in diameter, weighed only 78 g and cost under £3.50 in materials. Proxy user testing confirmed its ergonomic design and ease of attachment/detachment.