After a good night’s sleep, you wake up with a stiff neck and slightly “rusty” hands and wrists… This may be due to your sleeping position taken during the night. Especially if you adopt the so-called T Rex position, with your arms folded towards your chest.
A comfortable position, but with deceptively gentle effects
The “T. rex position”, whose name was popularized on social networks, refers to this way of falling asleep or waking up with your arms folded against your chest, as if you were trying to protect yourself or curl up in an invisible cocoon. At first glance, this posture seems completely natural. It reassures, envelops, and brings a feeling of immediate comfort. However, it is precisely this apparent innocence that makes her treacherous.
Dr. Gérald Kierzek, emergency physician, recalls that this repeated flexion of the arm for several hours exerts significant pressure on the nerves and vessels of the brachial plexus. “Keeping your arms bent night after night can cause prolonged nerve compression which can lead to damage, joint laxity and sometimes even lasting neuropathy.. This constant tension extends to the trapezius, shoulders and neck, disrupting all postural mechanics and limiting blood circulation.
Sleep specialists confirm this risk: when the arms remain stuck in this position for several hours, the nerve fibers can be irritated or compressed, producing this morning numbness that we too often brush aside with a simple “I slept badly”.
Why this position can actually damage your nerves
If this posture is problematic, it is firstly because it keeps the arms in an extreme flexion which reduces the space in which the nerves and arteries of the arm circulate. The ulnar nerve, for example, passes in a very narrow corridor at the elbow. Prolonged flexion increases the pressure on this already cramped passage, which can explain the tingling in the little and ring fingers. The radial nerve and the median nerve are also likely to be compressed when the arm is folded too close to the body or the neck.
Added to this is continuous muscular tension: the arm flexor muscles, the trapezius and the cervical muscles remain contracted throughout the duration of sleep. This muscular work, even if involuntary, tires the tissues, causes morning stiffness and can lead to migraines or persistent neck pain.
“This way of curling up promotes a general misalignment of the spine and upper body”
underlines our expert. “The neck may turn slightly, the pelvis pivot, the shoulders roll more. This repeated imbalance night after night accentuates the pressure exerted on the cervical or lumbar nerves, which contributes to reinforcing the feeling of discomfort or pain when waking up.”
The warning signs your body wants to show you
Doctors insist: certain symptoms must absolutely be taken seriously. Here are the main ones:
- Tingling, tingling or numbness in the arms or hands when you wake up;
- Pain in the shoulders, neck, back or onset of headaches;
- A feeling of weakness in the arms or loss of strength in the hands;
- Hands that “fall asleep” too often or for too long;
- Stiffness that persists several hours after waking up;
- Difficulty grasping objects or reduced sensitivity.
“If these manifestations last more than a few days, it is necessary to consult. They often reflect an irritated nerve, or even already partially damaged. The body does not “pretend”: it warns that the compression is no longer harmless.” insists Dr. Kierzek.
How to relearn how to sleep differently
It may seem strange to choose a position that ends up hurting. Yet cowering is deeply instinctive. This fetal posture provides a feeling of security, as if we were closing in on ourselves to protect ourselves from the cold, stress or tension accumulated during the day.
The solution therefore is not to force yourself to change your position, but to create an environment that naturally prevents the arms from folding. “Side sleepers can, for example, hug a body pillow against them, which provides comfortable support and prevents the arms from riding up. A small pillow placed between the chest and arms can also be enough to maintain a more neutral posture.”
For those who sleep on their back, the idea is to leave the arms alongside the body, sometimes placed on a pillow placed near the hips to prevent them from unconsciously rising. Just avoiding sliding your hands under the pillow or under your head already changes the pressure on the nerves enormously.
As summarized by Dr. Gérald Kierzek, adopting a more neutral posture, arms relaxed and open, improves circulation, reduces nerve compression and promotes complete muscle recovery.