Abstract: A flexible structural barrier is provided which is capable of yielding upon application of excessive force and immediately recovering to a rigid state with removal of the force, without either sustaining damage or imparting damage to the source of the force. The flexible structural barrier is made of a flexible material arranged to form a generally tubular structure when an appropriate air flow is establish therethrough. The flexible structural barrier is normally in a retracted or collapsed condition and is extended to an extended condition by the appropriate air flow, either automatically or upon demand. The barrier preferably includes an air flow source which is connected in fluid communication with the flexible material and is adapted to establish the appropriate air flow through the flexible material.