Example embodiments of the brace assembly utilize an elastic cross strap attached to mounting facilities about a joint to provide progressive resistance to the extension, flexion or other movement of body parts about the joint. In some embodiments for a knee joint, the brace assembly provides a progressive resisting force to resist hyperextension of the knee. Some embodiments of the brace assembly further comprise adjusting facilities to accommodate different joints, different size wearers of the assembly and different tension settings such as for athletes during competition. Some embodiments of the brace assembly may be used bilaterally and can be made without metal bracing to comply with the requirements of some sports.