Early Bronze Age stone wrist-guards are found across Europe from around 2400-1900 BC and are closely associated with the Beaker culture and Unetice culture. In the past they have been variously known as stone bracers, stone arm-guards and armlets, although "stone wrist-guard" is currently the favoured terminology.
The wrist-guards are small rectangles of stone (often slate) with a number of perforations, typically between two and six, which might allow attachment to the arm with cord. One, from Hemp Knoll in Wiltshire, had markings which clearly indicate its attachment to the arm by two cords. The shapes of the wrist-guard are stereotyped and common forms exhibit a narrowed 'waist' and curved cross-section (presumably so they fit the arm better). Stone wrist-guards are exclusively found in the graves of males, often lying next to the corpse's wrist. Rare examples - three in Great Britain - use rare imported greenstone and are decorated with gold-capped rivets or foil, clearly representing an elite form. The three British examples are from burials at Driffield, Barnack and Culduthel Mains in Scotland.
A wrist-guard is a device to protect the wrist. Wrist-guards are sold in skateboard, snowboard and sporting goods stores. They are worn also by people using a balance board.
The purpose of a wrist guard is to prevent the wearer from injuring their wrist or arm when falling. When a person falls forward, the typical response is to stretch their hands out in front of them to break the fall. In particularly violent or fast falls that are often associated with extreme sports, the forces associated with the fall can be large enough to cause severe bruising, dislocation or fracture of the wrist and arm bones. Wrist-guards prevent such injury with a plastic splint held on the inside of the wrist. The splint curves inwards towards the palm at the wrist joint, where it is exposed, and is concealed and held in place by padding at the hand and arm. When the wearer falls forward onto their hands, the curved plastic splint prevents the hand from hitting the ground, and the reduced friction of the plastic deflects the hands forward. Because of this reduced friction and forward deflection of the force of the fall, no weight can be put on the arm that is sufficient to cause any injury without the arm simply sliding forward. Although wrist guards can prevent arm injury, they have no effect on injuries to the shoulder, and dislocation or fracture is still possible, if not more likely due to the arm being thrown outwards.