Chiropractors are often asked, “Why does Carpal Tunnel Syndrome (CTS) bother me so much during the night?” Let’s take a look!
The carpal tunnel is made up of eight small carpal bones that bridge the forearm to the hand. Without these eight little bones, the motion at the wrist would be very restricted and limited to bending a little bit up and a little bit down. Think of all the things you are able to do with a large range of motion at the wrist like tightening a small screw by hand, pulling on a wrench, using a hammer, working under the dash or inside the engine compartment of a car, threading a needle, sewing, knitting, crocheting, and even washing dishes. As you can see, we put our wrists in some pretty strange positions!
Look at the palm-side of your wrist and wiggle your fingers. Do you see all that activity going on? Now, move your eyes slowly towards the elbow as you keep moving your fingers. It is pretty amazing how much movement occurs near the elbow just by moving the fingers! There are actually nine tendons that travel through the carpal tunnel, and these tendons connect your forearm muscles to the fingers. That’s why there is so much movement in the upper half of the forearm when moving your fingers, and in people with CTS, these muscles are usually overworked and super tight. This is why chiropractors work hard to loosen those muscles during treatment! These nine tendons are covered by a sheath, and friction between the tendon and the sheath is reduced by an oily substance called synovial fluid. When we repetitively and rapidly move our fingers, the friction that builds up produces heat, and if the oily synovial fluid can’t keep up, swelling occurs.
Any situation where there is increased swelling in the body can also promote CTS. For example, during pregnancy, hormonal shifts can result in a generalized swelling similar to taking BCP’s (birth control pills). Hypothyroid results in edema or swelling referred to as “myxedema” that can cause or make CTS worse. Some of the inflammatory arthritis conditions such as rheumatoid, lupus, scleroderma, and more can also predispose one to developing CTS. Obesity by itself is a risk factor for similar reasons.
So, why are we so susceptible to CTS symptoms at night? The main reason is that we RARELY sleep with our wrist in a straight or neutral position. We like to curl up in a fetal position and tuck our hands under our chin, bending the wrist to the full extent (90°). By doing so, the pressure inside the wrist “normally” doubles, but in the CTS patient, the pressure can increase by six times! This pinches the median nerve against the ligament that makes up the floor of the tunnel as it travels through the carpal tunnel, which then wakes us up and we find ourselves shaking and flicking our fingers to stop the numb, tingling, burning, pain that commonly occurs with CTS! This is why we prescribe a wrist brace for nighttime use and it REALLY helps! DON’T JUMP TO SURGERY FIRST – TRY CHIROPRACTIC FIRST!