Simply stated, ‘double crush’ means that if any given nerve is subjected to a proximal compressive neuropathy then it is more prone to the development of a second or ‘double’ distal neuropathy. Double crush syndrome was first described in the medical journal ‘Lancet’ in 1973. The term refers to a diagnosis of a compressed or trapped nerve in one area (e.g. the neck or thoracic outlet), with a second entrapment in another location (e.g. the carpal tunnel or Guyon’s tunnel in the elbow), with both entrapments contributing to symptoms. Some researchers suggest that the presence of an undiagnosed entrapment in another location may explain why some people still experience symptoms after carpal tunnel surgery. This has led manual therapists to question if examination of the hand alone is sufficient when dealing with syndromes such as carpal tunnel. Therapeutic outcomes are more successful when the nerves along the entire length of the arm are examined beginning proximally from the cervicothoracic spine down through the wrist and hand.