To determine the effectiveness of nocturnal splinting, Werner and his colleagues studied 112 active workers at a Midwestern automotive assembly plant with symptoms consistent of carpal tunnel but who had not sought medical treatment.
Subjects were selected if they experienced numbness, tingling, burning or pain in the median nerve of the hand for more than a week or for more than three times in the past six months. Werner notes that automotive assembly workers are five to ten times more likely to develop carpal tunnel than people than the general population and people who type for a living. Workers in the group too, miss, on average, a month of work, especially those who seek surgical intervention for advanced symptoms of carpal tunnel.
As part of the randomized controlled study, 63 study participants were fitted with a custom wrist-hand splint that maintained the wrist in a neutral posture overnight and were instructed to wear the splint at night for a period of six weeks. This group, along with the remaining 49 participants, also viewed a 20-minute video on carpal tunnel syndrome and how to reduce ergonomic stressors at work and home.
After the six week trial, about half of the splinted group reported significant improvement in their symptoms, with one participant reporting complete relief of symptoms. Compared to the group assigned to just watch the video, the splinted group had significantly decreased hand, wrist, elbow and forearm discomfort after three months.
After 12 months, the improvement seen in each group was greatly dependent on the individual's level of hand/wrist nerve damage. Of those in the non-splinted group, participants with healthy nerves noted reduced hand/wrist discomfort, whil