Wrist bending (even if at less than 20°) when sleeping amps up pressure on the wrist, aggravating carpal tunnel syndrome. Use a cock-up splint to keep the wrist in a neutral position. While typing in bed allows a more natural elbow position but it increases wrist extension. Using a split keyboard in bed causes lesser wrist deviation, but it's best to sit at a desk and type on a wider keyboard.
For those who have carpal tunnel syndrome (CTS), it’s no surprise that CTS is frequently most expressive during the night, often to the point of interrupting sleep and/or making it difficult to fall back to sleep.
Why is that?
Why Does CTS Flare Up At Night?
The primary reason for nighttime carpal tunnel syndrome (CTS) symptoms has to do with the wrist as it is very difficult to sleep with the wrist held in its “ideal” or least irritating position.
In fact, most people favor “curling” the back of the hand under the chin or bending the hand/wrist backward under the head. When the wrist is bent in either direction, it can increase the pressure inside the wrist, which can generate the various symptoms associated with CTS.
One study evaluated the pressure inside the carpal tunnel while participants slowly moved their wrists. The researchers found that many movements didn’t need to exceed 20 degrees before the pressure increased enough within the carpal tunnel to generate symptoms.
Because it doesn’t take a lot of movement to build up excessive pressure in the wrists of those with CTS, many doctors recommend the use of a “cock-up splint” for the nonsurgical treatment of CTS in order to help keep the wrist in a neutral position.
Wrist Posture Is A Contributing Factor
Wrist posture is also an important factor during the day.
One study looked at typing on a tablet PC, which allowed people to work in nontraditional settings. As the screen size reduced, the posture required to type became more limited and accelerated the usual rate of pain onset in the neck, elbows, and wrists.
This study also looked at three different positions used when working on touchscreen devices: desk, lap, and bed.
The healthy subjects completed six 60-minute typing sessions, using three virtual keyboard designs: standard, wide, and split.
The researchers monitored the position of the wrist, elbow, and neck while the participants typed and followed up each session with questionnaires designed to measure discomfort.
The research team reported that typing in bed required greater wrist extension but resulted in a more natural elbow position than typing at a desk.
The angled split keyboard significantly reduced the wrist deviation compared with the standard or wide keyboard designs.
All three regions — the neck, elbow, and wrist — exhibited more movements (13% to 38%) toward the end of the one-hour sessions, which correlated with a significant increase in pain in every body region investigated.
Overall, using a wider keyboard while sitting at a desk was the most tolerable position among study participants.