Embodiments of the hyperextension brace assembly utilize a cross-strap attached to mounting facilities about a joint to limit the extension of limbs about the joint. The cross-strap assembly is positioned from a cross origin behind the joint to attachment points on upper and lower mounting facilities on the upper and lower limbs and provides an opposing tensile force that limits the extension of mounting facilities and the limbs. In embodiments for a knee joint, the brace assembly provides a resisting force to resist hyperextension of the knee. Embodiments of the assembly are able to accommodate different joints, different size wearer's of the assembly and different tension settings such as for athletes during competition. Embodiments of the brace can be used bilaterally and can be made without metal bracing to comply with the requirements of some sports.