Associate Professor Norman A. Broadhurst
Senior Lecturer Musculoskeletal Medicine Flinders University of South Australia
Manipulation is defined as a form of manual therapy, which involves movement of a joint passed its usual end range of motion, but not passed its anatomic range of motion. This can be applied to any joint. What generally happens, is that the stretching of the capsule causes a negative pressure which provides a rapid release of gas into the space which produces the audible sound.
Spinal manipulation is usually considered as that of long lever, low velocity, non specific type manipulation as opposed to short lever, high velocity, specific adjustment.
There is no definitive concept of what actually happens to the joint which produces the pain for which manipulation is indicated.
Many hypotheses have been put forward and these are as follows:
- Release for the entrapped synovial folds.
- Relaxation of hypertonic muscle.
- Disruption of articular or periarticular adhesions.
- Unbuckling of motion segments that have undergone disproportionate displacement.
- Other suggested mechanisms for the relief of pain are the reduction of disc bulge, repositioning of miniscule structures within the articular surface and mechanical stimulation of nociceptive joint fibres.
While there is plenty of anecdotal suggestions as to who, when, where and why a manipulation should occur, most literature surveys would suggest that spinal manipulation should only be done for acute pain. The majority of studies have concentrated on patients after the epiphyseal fusion and prior to the onset of degenerative changes.
The outcome of the Quebec Task Force for Whiplash Associated Disorders (WAD) concluded that manipulation was not substantiated by any research which established either the short or long term benefits of a complete course of manipulation therapy. The immediate effect on pain and range of movements of a single manipulation is similar to that of a single mobilisation in neck pain of varying duration's. There is insufficient evidence for assessing the independent contribution of this technique. Their recommendation was that if manipulation were to be used, it is of short term duration and only to be applied by qualified personnel.
A Task Force on Low Back Pain established by the Royal College of General Practitioners came to a conclusion after looking at 36 randomised control trials of manipulation for low back pain found that many of these had very low methodological scores. However, 19 of these trials reported positive results for those people suffering acute back pain with no referred pain pattern.
The conclusions were:
Within the first six weeks of onset of acute and recurrent low back pain, manipulation provides better short term improvement in pain and activity levels and higher patient satisfaction than the treatments to which it has been compared. However, there is no firm evidence that it is possible to select which patients will respond or what kind of manipulation is most effective.
The evidence is inconclusive as to whether manipulation for low back pain of more than six months duration provides clinically significant improvement in outcomes compared with other treatments and there is conflicting evidence from randomised control trials and systematic reviews on the effectiveness of manipulation in chronic low back pain.
Risks of manipulation for low back pain are very low provided patients are selected and assessed properly and it is carried out by a trained therapist or practitioner. Manipulation should not be used in patients with severe or progressive neurological deficit in view of the rare but serious risk of neurological complication.
hen considering complications from manipulative procedures a review of the literature would indicate that there is very little in the way of complications which arise from lumbar or thoracic manipulation. However, this is not so for cervical manipulations. Winer reviewed the literature up until 1985 and he found that until 1980 there were 58 reported tragedies from cervical manipulation most of these were strokes of one degree or another and only one death. Since 1980, there have been a variety of reports in the literature with several deaths occurring in Australia with the major cause being neurological deficit mainly involving brain stem infarction. Koes et al listed several criteria which need to be taken into consideration for a trial to be considered worthwhile. The conclusion from this study indicated that the efficacy of manipulation had not been convincingly shown and that further research needs to pay strict attention to the methodological quality of the study design. This is a frequent conclusion of many of the review studies.
Good trials of comparing experts with experts have not been carried out and many of the tragedies have occurred in young people with no vascular pathology. This means that testing for vascular insufficiency will not prevent the rare but unwanted complication. The paper by Twomey and Taylor suggested that manipulation was efficacious in the treatment of acute mechanical low back disorders and emphasised the importance of stretching exercise as an integral part of the treatment for people with low back pain advocating its use in conjunction with both manipulation and mobilisation. Assendelft et al reviewed the recent literature on spinal manipulation and found 295 complications and that 60% were due to some sort of vascular complication with 22% involving disc herniation or progression to cauda equinae syndrome. They estimate a complication rate of less than 1 per 1 million cervical manipulations and conclude that complications are probably under-reported in the literature.
If the literature is so clear on the fact that spinal manipulation is only to be considered in acute injuries and certainly within the first six weeks of such an injury, even then the efficacy is not particularly substantial. One therefore needs to ask the question as to why there is so much manipulation being performed in the community when there is no good scientific data to support such an activity.
Could it be that there is a particular cohort of patients, for whatever reason, require manipulation from time to time? One can assume that most people are reasonably intelligent and do not seek any kind of therapy just for the sake of having it done. They do derive either pleasure or benefit or both from the particular manipulative procedure. A more cynical thought is that some people are brainwashed into thinking that their regular manipulation is similar to the soma of "Brave New World".
If spinal manipulation is to have an high degree of efficacy, then there needs to be some mechanism for the selection of patients who will strongly benefit from manipulation as opposed to those who might benefit from some other established procedure. While some of us might think that we are particularly good at doing our task and have a multitude of thankful patients who testify to our skill, there is no strong scientific basis for our practice. We can be greatly comforted by anecdotes but if we are to practice evidence based medicine, then one would have to conclude, along with the majority of review studies, that more needs to be done in order for us to be practitioners of the best practice.
Manipulation should not be considered as the only treatment for musculoskeletal problems. To be good at musculoskeletal management, a multitude of skills need to be learnt and used.
Further musculoskeletal skills can be achieved by attending Post Graduate programs such as that offered at the Flinders Medical Centre where both the skills of the procedure are learnt as well as the assessment of the efficacy from the literature.
Acute Low back pain 1996 RCGP http:s//www.rcgp.org.uk/back pain/rcbp 0007 htm
Winer C. Catastrophies following forceful cervical manipulation AAMM Bulletin June 1986 28-30
Pope MH, Phillips RB et al A prospective randomised three week trial of spinal manipulation, TENS, Massage & Corset for Subacute LBP. Spine 1994 19: 2571-2577
Shekelle PG. Spine update-Spinal manipulation Spine 1994 19: 858-861
Ottenbacher K. Difabio RP. Efficacy of spinal manipulation/mobilisation therapy - a meta-analysis. Spine 1985 10: 833-837.
Koes BW, Assendelft WJJ. Spinal manipulation and mobilisation for back and neck pain: a blended review. BMJ 1991 303: 1298-1303.
Twomey L, Taylor J. Spine update - Exercise and spinal manipulation in the treatment of low back pain. Spine 1995 20: 615-619.
Shekelle PG, Adams AH et al Spinal manipulation for LBP Ann. Int. Med. 1992 117: 590-598.
Assendelft WJ, Koes BW et al. The relationship between methodological quality and conclusions in reviews of spinal manipulation. JAMA 1995 274 : 1942-1948.
Assendelft WJ, Bouter SM, Knipschild PG. Complications of spinal manipulation: a comprehensive review of the literature. J. Fam. Pract. 1996 42: 475-480.