Hello and welcome back to the ThreeSpires Physiotherapy blog, apologies for the delay in this blog post but we have been incredibly busy recently (which is fantastic) and so it has been very difficult to find the time to sit down and complete a blog. As a physiotherapist I am constantly trying to improve my understanding and knowledge base and as such I generally attend several courses per year covering a wide range of topics. For this blog I thought that it might be interesting to discuss the subject of a physiotherapy course that I recently attended - Thoracic Outlet Syndrome. This is an unusual condition affecting the upper limbs that is often misdiagnosed or missed in assessments and affects a surprisingly large number of patients.

 The thoracic outlet is an area of the body between the neck and the upper arm (sorry but it will be necessary to do some anatomy!) through which all of the nerves, veins and arteries that supply the arms run. In the unhealthy looking model to the right the thoracic outlet is in the triangle between the neck and collar bone (clavicle).  Sometimes something in this area will squash one of the nerves, veins or arteries and give the patient problems in the arm and hand. In the majority of patients with thoracic outlet syndrome (possibly as high as 95%) it will be the nerve that is compressed and they will often experience pins and needles, weakness or pain in the arm and hand. To understand more fully what might happen and how these structures might be compressed we need to have a look at the area in more detail.

Firstly, as the spinal cord comes down the neck it sends nerve roots out that send impulses to various parts of the body - this can be seen by looking at the picture to the right in which the yellow bits pointing out to the sides represent the nerve rots leaving the spinal cord. The nerve roots between C5 (cervical vertebrae 5) and T1 are responsible for the sensation and musculature control of all the arm, forearm and hand. As they leave the spine and move towards the shoulder they intermingle and join each other to form the brachial plexus - this is just around the area by the collarbone. Each individual nerve root joins and crosses over with the others several times to eventually form the major nerves of the upper limb - the ulnar nerve, radial nerve and median nerve (there are others including the musculocutaneous nerve but for the purposes of this blog they will be enough!). One nerve in particular is well known and everyone who is reading this blog will have experienced irritating it at some point: the ulnar nerve runs down the arm crosses the back of the elbow (in fact you can feel it at this point and will have irritated it before as it is the funny bone!) it then runs down the forearm and supplies sensation and strength to the little finger and part of the ring finger.

This brachial plexus and the major artery and vein of the arm run through an incredibly tight space between the scalene muscles of the neck, underneath the clavicle (collar bone), beneath pectoralis minor (one of the chest muscles) and the shoulder and then finally they enter the arm. At several points in this journey they can easily be compressed by the scalene muscles, the clavicle and first rib (the most common site of compression) and finally between pec minor and the shoulder. As mentioned before it is the nerves that are most commonly compressed and in the majority of thoracic outlet cases it will be the nerve roots of C7-T1 that will be compressed, this often gives patients pain and pins and needles down the back of the arm and into the little and ring finger of the hand. This will often be mistaken as ulnar nerve compression and needs a thorough assessment to make a clear diagnosis.

Perplexingly and possibly the reason that thoracic outlet syndrome is so poorly recognised is that the patient's symptoms will often be very intermittent and be position specific. For example they may only have problems when they lift their arms above their shoulder height as at this point the nerve will become compressed and they will lose power or experience pain etc.. Often these patients will have had nerve conduction assessments that have shown normal nerve function due to the fact that the nerve conduction test took place with their arm at their side.

In a minority of patients with thoracic outlet syndrome they will have arterial or venous compression that affects the circulation of the arm. These patients can sometimes have swelling of the upper limb, it may become pale or even slightly blue and frustratingly they may also experience pins and needles which may lead the clinician to suspect nerve compression. Only a thorough clinical assessment including blood pressure assessment of each arm can determine if their symptoms are coming from the thoracic outlet.

So, I guess a reasonable question from most physiotherapy patients would be what is causing this and what can I do about it? Well firstly it is likely that there is large postural component to the reasons that the nerves or circulation are being compressed. Having a poor neck and shoulder posture (slouching, with rounded shoulders and a chin pointing out) will reduce the space available in the thoracic outlet region. People who spend large parts of their day hunched over a PC will be at increased risk of thoracic outlet syndrome and the picture to the right shows a good example of a terrible posture at the computer. Sometimes a previous traumatic incident can be responsible - for example a fracture of the clavicle can cause an enlargement of one part which may compress either the nerves or circulation. In general patients respond with thoracic outlet syndrome will respond well to physiotherapy including some manual therapy, myofascial release, stretching of tight musculature and postural improvement.

If you suspect that you or someone you know might have thoracic outlet syndrome then I would advise that you contact us for a thorough assessment and treatment of your condition. For anyone reading this blog that does not know, we provide a home visit physiotherapy within 25 minutes of Lichfield in Staffordshire and can be contacted on 0788 428 1623 or via enquiries@threespiresphysiotherapy.co.uk