The Treatment of Sciatica by Physiotherapists
Sciatica results from a structure impinging on a lumbar nerve root, causing compression and/or inflammation enough to cause neurological changes in the skin, reflexes and muscles served by the affected nerve. Not a common syndrome, it is estimated that 3-5% of the population suffer this kind of problem at some time. It affects men and women equally with men most susceptible in their forties and women in their fifties. Up to a quarter have symptoms which last more than six weeks and referral to physiotherapists for acute management is routine.
Disc prolapse can result in the internal nuclear material being extruded past the outer disc wall, physically compressing the nerve root which runs nearby. The nuclear material is also chemically irritating to the nerve structure and these irritants make the nerve and nearby structures swell, partly blocking the local circulation and the nerve's message transmission. Disc prolapse is typically the cause of proper sciatica but the size of the prolapse is not closely related to the amount of pain the person suffers.
The lumbar discs are more likely to have prolapses due to the high levels of force they have to endure. When we lift things away from the body, bend over at the waist or perform standing activities the back has to cope with the leverage involved. When stresses are loaded onto the discs the hydraulic mechanism magnifies the forces on the outer walls by three to five times that which the skeleton has to cope with. With time these stresses cause failure of the outer disc material and allow prolapses to occur.
The onset of lumbosacral radiculopathy is often sudden with low back pain and any back pain may disappear at the start of the leg pain. Worsening factors are sneezing, coughing and sitting with lying down or standing up common easing factors. Sciatic pain typically occurs in the buttock, back or side of the leg and calf and into the foot. If the disc prolapse is higher up (prolapses at disc levels L1 to L3 are 5% of the total) the pain may be in the front of the thigh no further than the knee. A patient may have an isolated area of pain and still have a prolapse.
Red flags are potential warning signs that the patient's back pain could be caused by a medical illness and they need referral to a medical advisor for an opinion. The physio will ask about any weight reduction, difficulty passing water or stools, feeling unwell or having a fever, night pain, poor appetite, a serious past medical history and note whether the patient is younger or older than typical back pain onset age. The physiotherapist will also record the areas of pain, the types of pain reported and the response of pain to postures and activities.
A patient with lumbar radiculopathy may exhibit abnormal posture, sometimes bent forward and unable to bend backwards, with a one-sided trunk shift. Physiotherapists check the ability to perform spinal movements, any pattern of limitation or tendency for the pain to centralise on repeated movements. Physios will test the reflexes, sensibility and muscle power to perform the neurological examination. This and the straight leg raising test allow the physio to check which of the spinal nerves is likely to be the culprit.
The McKenzie technique works on pain centralisation, the tendency for pain to move towards the back from the legs, suggesting a disc problem, and many physios use this technique. Pain in the front of the thigh and over the knee can be referred from the hip joint, so the physiotherapist will assess the lower limb joints to check the diagnosis. A thorough examination informs the physiotherapist of the likely diagnosis and how they might treat the syndrome, or that the patient needs to be referred to a medical practitioner for a consultation and investigation.
Physiotherapists use a variety of therapies to treat sciatica, with McKenzie technique being a mainstream technique for discogenic pains. Mobilisation and manipulation techniques, core stability work, myofascial release, specific exercises, manual techniques, soft tissue work and massage, analgesia, patient education, rest, the best position to relieve extreme sciatica pain and advice are all used as treatments. Most sufferers settle without investigation or surgery and a long term exercise programme is useful once the problem has settled.
by Jonathan Blood Smyth