This case report presents the most common type of traumatic thumb injury: a fall onto an outstretched hand causing hyperextension and hyperabduction of the 1st metacarpophalangeal joint (MCP). This paper will discuss the various approaches for conservative management of this disorder and take the reader through the ten-month progression of evaluation and treatment that the patient received following such an injury. Treatment included immobilization/splinting, exercise, phonophoresis, injection, surgery, and the Mulligan approach to mobilization with movement. This report also illustrates the difficulties and crucial need for careful and thorough differential diagnosis. It also demon- strates the need to address the arthrokinematics of the joint in this type of injury and illustrates the benefit of the mobilization with movement approach.