Symptoms of CTS occur when any condition decreases the size of the carpal canal or increases the volume of the structures within the carpal canal, compressing the median nerve. One cause of the symptoms of CTS is the incursion of the lumbrical muscles of the hand into the carpal canal. Individuals with CTS tend to have tight lumbrical muscles which increase this incursion, thereby increasing CTS symptoms. An intervention designed to reduce the incursion of the lumbrical muscles should have an effect on the symptoms of CTS.

The purpose of this study is to systematically examine the effect of an intensive lumbrical muscle intervention, splinting to prevent lumbrical muscle incursion and lumbrical muscle exercises, on the symptoms of CTS. This project will be a randomized clinical trial to evaluate the effectiveness of a home program targeting the lumbrical muscles. One hundred and twenty subjects will be assigned to one of 4 groups: Group 1 will receive a home program of lumbrical muscle stretches combined with a lumbrical positioning splint; Group 2 will receive a home program of lumbrical muscle stretches combined with a night wrist cock-up splint; Group 3 will receive a home program of general stretches combined with a lumbrical positioning splint; and Group 4 will receive a home program of general stretches combined with a night wrist cock-up splint. After 1 month, 3 months, and 6 months the groups will be compared to determine if there is a significant reduction in symptoms between the groups.

Inclusion Criteria:

• At least 18 yo
• Clinical symptoms of Carpal tunnel syndrome (CTS)
• Positive Tinel's, Phalen's, or Durkin's test
• Absence of thenar atrophy
• 2 pt discrimination of 5mm or less

Exclusion Criteria:

• Persons needing immediate CTS surgery
• Pregnancy
• Compressive neuropathy in the ipsilateral arm
• Diabetes
• prior CTS release
• Non-English speaking