Arm wrestling places significant torque on the humeral shaft. A spiral distal humeral shaft fracture is an unusual but significant injury that can result. Of 93 patients who presented between 2009 and 2017 with closed humeral shaft fractures that were managed nonoperatively, 9 sustained the fractures while arm wrestling. Outcomes were compared with those of all other patients with nonoperatively managed humeral shaft fractures sustained through other mechanisms. The Student's t test was used to compare cohorts.