The effect of wrist guards on bone strain in the distal forearm

There are increasing epidemiologic and biomechanical data suggesting that w rist guards are effective in preventing wrist injuries in snowboarders and in-line skaters. However, there have been few studies designed to determine how they function. In this study we explored the load-sharing function of wrist guards at subfailure loading levels. To do so, we measured bone strai n in the distal radius, distal ulna, and midshaft of the radius in cadaveri c forearms with and without two types of commercially available wrist guard s. We also measured construct stiffness and energy absorption during testin g. Our most significant findings were that dorsal and volar distal radius b one strain were reduced with both wrist guards, and wrist guards increased energy absorption. We also found a reduction in dorsal distal ulnar bone st rain, but only with the one guard in which the volar plate was elevated off the heel of the hand, In our loading configuration, wrist guards did not i ncrease bone strain at the radial midshaft. These findings provide insight into how wrist guards protect the wrist: during low-energy falls they funct ion partly by load-sharing, as well as by absorbing impact energy.