»: The double crush hypothesis originally proposed that compression of a peripheral nerve at a proximal site increases its susceptibility to additional distal lesions. »: The etiology of double crush syndrome is likely multifactorial as mechanical, systemic, pharmacologic, or environmental factors may increase a patient's susceptibility to this syndrome. »: To date, there remains no standardized definition of double crush syndrome, and there is no consensus on its exact pathophysiology or diagnostic criteria. »: Patients with double crush syndrome should be counseled that surgical repair may produce inferior outcomes compared with those who are treated for isolated entrapment neuropathies.