You reach up to hang the washing, paint a ceiling or fix your hair, and within a minute your arm feels heavy and your fingers start to tingle. You wake at night with a numb hand because you have slept with your arm above your head. The wrist has been tested for carpal tunnel and it is fine. The neck scan came back clear. So what is it?
Quite often, the answer is thoracic outlet syndrome: a squeeze on the nerves and, less commonly, the blood vessels where they pass from the neck into the arm, through a narrow gap between the collarbone, the first rib and the neck muscles. Nobody searches for it by name, because nobody knows the name. Here is what it is and what helps.
In this article
What is thoracic outlet syndrome?
The thoracic outlet is the passage at the base of the neck through which the bundle of nerves that supplies the arm (the brachial plexus) and the main artery and vein to the arm all travel. It is bordered by the collarbone above, the first rib below, and the scalene muscles of the neck and the pectoralis minor muscle of the chest along the way. It is a tight space by design, and several things can make it tighter: a forward, dropped shoulder posture, tight or overworked neck and chest muscles, a previous neck or shoulder injury, repetitive overhead work or sport, and in a small number of people an extra rib at the base of the neck.
When the nerves are compressed, the result is neurogenic thoracic outlet syndrome. When the vein or artery is compressed, the result is the vascular form, which is much rarer and behaves differently.
What does it feel like?
The neurogenic type typically produces aching, heaviness, tingling or numbness that runs from the shoulder or collarbone region down the arm and into the hand, often the ring and little finger side. The defining feature is that it is worse with the arms raised or overhead and with sustained carrying, and it can wake you at night if your arm ends up above your head. A dull ache across the top of the shoulder and the shoulder blade is common, and people often describe the hand as clumsy or weak when the symptoms are active.
If that pattern sounds familiar, our physiotherapy in Mount Gravatt team can assess the whole pathway from neck to hand and tell you whether the outlet is the problem.
Who gets it, and how common is the nerve type?
Who it affects
It affects women three to four times more often than men, and symptoms most commonly develop between the ages of 20 and 50. Previous neck or shoulder injury, repetitive overhead work and posture are the usual contributors.
The people we tend to see with it are painters, hairdressers, electricians and others who work with their arms up, swimmers and overhead athletes, musicians, and desk workers whose shoulders have gradually rolled forward. It is often missed for a long time because the wrist and the neck get tested first, and both can look normal.
Arm going numb when you lift it? A physiotherapy assessment at ACE Sports Medicine in Upper Mount Gravatt includes the positional tests that pick this up.
Why is it not carpal tunnel?
Carpal tunnel syndrome compresses the median nerve at the wrist and affects the thumb, index and middle fingers, typically worst at night and with gripping. Cubital tunnel syndrome compresses the ulnar nerve at the elbow and affects the ring and little finger, worst with a bent elbow. Thoracic outlet syndrome sits above both of them, can affect the whole hand or the ring-and-little-finger side, and is triggered by arm position at the shoulder rather than at the wrist or elbow. The arm-overhead trigger and the shoulder and collarbone ache are the clues that point higher up the chain.
A careful assessment works through the neck, the outlet, the elbow and the wrist in turn, because nerve symptoms in the hand can come from any of them, and occasionally from more than one.
What actually helps?
For the neurogenic form, conservative physiotherapy is the accepted first-line treatment, and surgery is reserved for persistent, severe cases. A typical programme has four parts. First, easing the muscles that narrow the outlet, particularly the scalenes at the side of the neck and pectoralis minor at the front of the shoulder, with hands-on treatment and specific stretches. Second, restoring the posture and shoulder-blade control that keeps the outlet open, which usually means strengthening the mid-back and the muscles that hold the shoulder girdle up and back. Third, nerve mobility exercises so the nerves glide rather than snag. Fourth, changing the loads: how you carry bags, set up your desk, sleep, and pace overhead work.
Many people improve well with this approach over a course of weeks to months. Progress is measured by how long you can hold your arms up before symptoms start, and by night-time and work symptoms easing.
When should you seek help?
Occasional tingling from an awkward sleeping position is not a reason to worry. Persistent, position-related arm symptoms are worth assessing, and a few signs need prompt medical attention.
Consider getting assessed if
Arm tingling, numbness or heaviness keeps returning with overhead activity or carrying; it is waking you at night; your hand feels clumsy or you are dropping things; or a wrist or neck assessment has not explained it. Seek same-day medical care if the hand or arm becomes cold, pale or blue, swells suddenly, or you notice visible muscle wasting in the hand, as these can indicate vascular or advanced nerve involvement.
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Helping You Perform at Your Best
Our physiotherapy team at ACE Sports Medicine in Upper Mount Gravatt assesses arm and hand nerve symptoms for people across Brisbane's southside, from the painter whose arms give out on the ladder to the swimmer whose hand goes dead mid-set. Thoracic outlet syndrome is frequently missed, and it often responds well once it is recognised.