Feeling as if your hand is “asleep” is a common symptom in individuals with carpal tunnel syndrome. The primary areas affected include the palmar side of the thumb, index, middle, and partial ring finger. Individuals who are deemed obese (BMI>29) are 250% more likely to develop CTS than those with a BMI<20. Similarly, people who have jobs performing repetitive motions have a higher chance of developing carpal tunnel syndrome. Numbness and tingling may occur when pressure is increased in the carpal tunnel.
Inside the carpal tunnel there are 9 tendons and the median nerve which is all housed in the palm of the hand. During finger flexion, muscles in the hand called the lumbricals cascade into the carpal tunnel. The 4 lumbricals coupled with the 9 tendons can significantly increase pressure within the tunnel thereby exacerbating symptoms. The pressure inside the carpal tunnel also increases with both wrist extension and flexion. Consequently, those who sleep with a flexed wrist posture may cause compression on the nerve.
Ways to treat/prevent carpal tunnel include: activity modification, splinting, stretching, weight loss, and maintaining proper posture during prolonged tasks. Examples of activity modification may include taking breaks throughout the day during repetitive tasks, utilizing an adjustable sit/stand desk, proper hand position during typing activities, and having split keyboard to prevent excessive wrist movements. Splinting may assist in correcting wrist/hand position. If you experience carpal tunnel symptoms follow up with your primary care physician to determine the best course of action.
Evans, R (2011). Rehabilitation of the hand and upper extremity. Therapist’s management of carpal tunnel syndrome. Pp666-671.