Abstract: A chin strap assembly incorporating a semi-rigid, flexible support member formed of plastic or other resilient material and having upwardly extending end portions which bear upwardly against first and second sides of the wearer's jawbone, and a downwardly arched center portion which relieves the soft-tissue, hypoglossal area of the throat from upward pressure generated by tension on the helmet strap thereby rendering it easier for the wearer to breath under exertion. A fabric wrap fits over the strap and support members to hold the latter in place at the desired location, and the wrap also provides cushioning for the wearer's jaw.