Studies indicate that about 80% of patients consult a chiropractor for the assessment and treatment of neck pain, thoracic back pain, or lower back pain. The primary treatment they receive is spinal adjustment or manipulation. There have been more studies and randomized controlled trials (RCTs) on manipulation for the treatment of back pain than on any other back pain treatment (RAND 1992, Manga 1993). These studies have been conducted by the medical, osteopathic, physiotherapy and chiropractic professions. Many have shortcomings but overall they provide strong evidence that manipulation has a positive and beneficial outcome in the treatment of back-related disorders. Appendix 1 contains references to controlled clinical trials of manipulation and mobilisation in the treatment of low back pain and in the treatment of neck pain.
In virtually all of these studies, manipulation has been shown to be more effective than anything to which it has been compared. A few studies found no difference. In no study has manipulation been shown to be less effective than other treatments or no treatment. It should be noted that the RCTs are not without design problems and they have been subjected to much critical analysis (Deyo 1983).
There are approximately 200 named chiropractic adjustive technique systems. However, there is a great deal of overlap between these, and a number of techniques involve only minor modifications of others. Additionally many named techniques have both analytical and therapeutic components. Only the treatment portions of technique procedures are presented here. All chiropractic techniques that are taught in Council on Chiropractic Education (CCE) accredited colleges are used and recognized in Canada.
A number of approaches to rating the appropriateness of chiropractic manipulative techniques or procedures have been reviewed. Kaminski (1987) proposed an algorithm leading to the classifications of fully accepted, provisionally accepted and unsubstantiated. This algorithm provides general guidelines for the review of procedures based on the reasonableness of the models, utility in practice, and scientific investigation of procedures. This algorithm has been adopted as a guide for rating techniques in this chapter, with some differences in terminology and categorization which incorporated valuable concepts from others (Keating 1991, Coulter 1990 and Vear 1991). Areas of inquiry are:
1. Definition - Modus Operandi/Rationale:
Questions asked are: what are the assumptions, beliefs or principles underlying technique; are these claims consistent with accepted health science principles (e.g. in physiology, biomechanics, psychology). Is the technique largely theory driven or is there a strong empirical base?
2. Effectiveness/Claims:
Effectiveness refers to the ability of a given procedure or group of procedures to produce a desired effect under actual conditions of use. This must be compared with the claims made by those supporting the technique/procedure. The presence and sufficiency of data in support of these claims must be analyzed.
3. Safety/Harmful Effects:
Safety refers to the acceptability of any risk involved arising from application of a specific procedure or group of procedures by an appropriately trained practitioner.
4. Acceptance Within Accredited Chiropractic Colleges:
This is a relevant criterion for assessing a procedure. However, it is only one criterion, and does not mean that new techniques cannot be found acceptable, but it does assume that new techniques are initially considered as either experimental or investigational (Coulter 1990).
A. Manual Articular Manipulative and Adjustive Procedures
1. Specific Contact Thrust Procedures
(i) High-velocity thrust: In the guidelines the term "conditions of altered physiologic function" has been used in the context of somatovisceral effects and the management of conditions that are not musculoskeletal. This term better suits the traditional chiropractic philosophic construct than the terms "organic condition" or "Type O Disorders" which may be construed to include conditions of clearly organic pathology. An important distinction must be made between treating organic disease and treating patients with organic disease. In this context chiropractors have a primary therapeutic goal of correcting spinal subluxations. This in turn normalizes neurologic function and promotes the healing process (Wiles 1990).
(ii) High-velocity thrust with recoil: There is little evidence in the literature specifically evaluating the traditional high-velocity thrust with recoil that was first taught in chiropractic colleges and has been traditional among chiropractors. Although in one sense distinct in application due to the recoil, joint cavitation occurs with this procedure on a similar basis to the dynamic thrust without recoil. Although trials are needed to compare these two types of thrust, it is likely that such trials would show similar clinical outcomes.
(iii) Low-velocity thrust: Low-velocity thrust procedures do not usually result in joint gapping. This type of procedure is typically chosen for patients who have exhibited intolerance to more forceful high-velocity approaches.
The literature on mobilization substantiates the value of low-velocity thrust procedures, which have their effect in the passive range of joint motion. In general this literature seems to favour manipulation over mobilization in the treatment of neuromusculoskeletal conditions.
2. Non-specific Contact Thrust Procedures
Non-specific contact thrust procedures are those that do not involve direct contact between the doctor and the articular segments to be manipulated. Typically these include long-lever contacts. In addition, general mobilization techniques are considered. The ratings of these procedures tend to involve the same issues as for high-velocity and low-velocity thrusts. There is some anecdotal evidence that specific contact procedures have greater effectiveness than general non-specific contacts or general mobilization.
(i) Mobilization:
Thrusts or movements may be high or low-velocity, high or low-amplitude, and short or long-levered. They are all applied in a similar manner to manipulative thrust but typically are slower and of less overall force. Movement remains within the active and passive ranges of motion of the joint. Typically there is no cavitation and, unlike manipulation, the joint is not carried to the paraphysiologic zone.
Mobilization techniques are the mainstay of osteopaths, physical therapists and others who provide manual care. Much of the clinical outcome literature on mobilization is blended with the manipulation literature. A large number of the trials on manipulation do not distinguish between manipulation and mobilization. Variations of mobilization include oscillation and passive stretch procedures.
3. Manual Force, Mechanically Assisted Procedures
(i) Drop Tables and Terminal Point Adjustive Thrust:
This procedure is a dynamic thrust with or without recoil. Proponents of the various manual but mechanically assisted approaches to manipulation view these procedures as similar to traditional spinal manipulative techniques. There appears to be no evidence that these techniques are harmful, and indeed most expert anecdotal evidence is that these techniques are relatively low-force and safe.
(ii) Flexion-Distraction Tables (including all Traction Tables):
These devices allow for manual or mechanical traction to be applied primarily to the lumbar and lower thoracic spine, as other ranges of motion are introduced by manipulation. The literature on this technique is quite abundant and supports conclusions of safety and effectiveness. This procedure can also be considered a form of passive stretch or mobilization, and accordingly the literature for those procedures is of application.
In both the literature and practice there is use of flexion-distraction tables for the treatment of patients with lumbar disc herniations. There is evidence of effectiveness, but not more so than for use of traditional side-posture rotational manipulation.
4. Mechanical Force, Manually Assisted Procedures
(i) Pelvic Blocks:
These are paired wedges that are primarily used for positioning and stressing the lumbosacral and sacroiliac joints. In addition, various manual oscillation and stretching procedures are typically used in conjunction with blocking procedures. The technique that primarily utilizes blocking procedures is known as Sacro-occipital Technique (SOT). These procedures are also utilized in Applied Kinesiology.
These techniques tend to be gentle, and the literature on passive stretch, mobilization, and myofascial soft-tissue work is applicable here.
(ii) Mechanical Adjusting Devices:
There are a number of mechanical devices in use as an aid to manipulation. Proponents consider that there may be a better ability to control amplitude, velocity, patient position and pre-stress with the result that there is a more effective form of manipulation with some patients. Such devices have been suggested for use with patients at risk of vertebral artery syndrome and patients with contraindications for more forceful manipulation (Byfield 1992).
The evidence suggests that these devices produced tissue movement but typically do not result in joint cavitation. There is evidence in the literature that some of these devices are of value in treatment of neuromusculoskeletal conditions (Osterbauer, Deboer, Fuhr 1993, Osterbauer, Derickson et al. 1992, Richards, Thompson et al. 1990), and for alteration of physiologic function (Frach et al. 1992, Phillips 1992, Yates et al. 1988).
An in-depth review of each instrument is beyond the scope of this paper. The device most commonly used is the activator.
B. Manual Non-articular Procedures
1. Manual Reflex and Muscle Relaxation Procedures
(i) Muscle Energy Techniques:
A variety of procedures fall under this classification, including post-facilitation stretch, proprioceptive neuromuscular facilitation, post-isometric relaxation, and reciprocal inhibition. In addition there are named chiropractic technique systems (e.g. applied kinesiology and sacro-occipital technique) that use these procedures amongst others. Muscle energy techniques are based on the concept of neurologic or physiologic muscle spasm. Treatment is directed at these areas with the patient producing voluntary muscle contractions, typically against manual passive resistance from the practitioner, in order to cause a reflex relaxation of a muscle. These techniques are in widespread use and are subject to much investigation. They are taught in virtually all chiropractic colleges as part of the core curriculum.
There are few if any concerns about safety. However there are relatively few formal studies of effectiveness. The one study which compares the effectiveness of muscle energy techniques and manipulation for the treatment of neck pain indicates that both techniques appear to be effective, but with manipulation producing superior benefit. (Cassidy et al. 1992).
(ii) Neurologic Reflex Techniques:
There are a variety of techniques to stimulate proprioceptive and other sensory nerve endings to cause reflex effects. Experimental evidence suggests that mechanical stimulation may influence muscle relaxation, sudomotor activity, vaso constriction/dilation, and gastric secretions. However, clinical studies exist only for somatic conditions.
Scientifically there are unresolved concerns in this area. No well articulated or substantiated physiologic rationale exists for effectiveness. More detailed investigation is necessary before these techniques can be regarded as having any proven clinical effectiveness.
(iii) Myofascial Ischemic Compression Procedures:
Ischemic compression involves placing a sustained compressive force on a tightly contracted muscle to relax the muscle. Chiropractors have traditionally employed myofascial ischemic compression procedures - the Nimmo technique is perhaps the most well known of these. These procedures are taught as part of the core curriculum in virtually every chiropractic college in North America, but there has not yet been a clear identification of the physiologic nature of the lesions treated and there are no well-designed outcome studies.
(iv) Miscellaneous Soft Tissue Techniques:
There are many different types of soft tissue techniques. They are standard in applying manual pressure to relieve muscle spasm. Some common techniques of muscle work include massage (superficial, effleurage, petrissage, percussion), pressure point work (acupressure and shiatsu), and deep tissue techniques (rolfing, etc.). There is little controversy regarding the clinical utility of such procedures for relaxation and uncomplicated musculoskeletal problems. Support in the scientific literature, however, is sparse.
C. Miscellaneous Procedures
1. Neural Retraining Techniques
A variety of procedures aimed at developing neuromuscular coordination exist within and outside the chiropractic profession. Such procedures make up portions of some popular techniques. These approaches primarily involve repeated activity movements under a variety of mechanical conditions in order to pattern the motor system for particular activities. There is some overlap with other reflex procedures including muscle energy techniques. Examples of these approaches include Feldenkreis, Alexander, Cross-Crawl. There is little to no literature available to provide acceptable scientific evidence of the effectiveness of these techniques.
D. Non-manual Procedures
1. Exercise and Rehabilitation
There is now good evidence, in the general health sciences and sports sciences literature, for the use of exercises in active management of musculoskeletal conditions and in rehabilitation.
2. Back School/Spinal Care Courses
Patient education on spinal care, at the time of treatment of in back schools, has traditionally been an integral part of chiropractic case management for patients with spine-related disorders and is a growing part of medical and multidisciplinary management. Its value is now well supported in the literature.
3. Electrical Modalities
Typical examples of electrical modalities are interferential current, MENS and TENS. The most thorough controlled trial of TENS suggests it may be less effective than exercise for patients with chronic low-back pain (Deyo et al. 1990). Overall evidence and clinical experience suggest these modalities are of value in the treatment of back pain and other musculoskeletal conditions. However the evidence is not nearly so strong as for manipulation and exercise and further research is required.
4. Laser Therapy
Laser therapy, involving stimulation of tissue using a 10 milliwatt or infra-red laser beam, is now in widespread use by chiropractors and other health professionals for treatment of lesions in ligaments, tendons and myofascial tissues. More outcome studies are required (Gam et al. 1993).
Helium neon and infra-red laser energy have been used in the stimulation of acupuncture points. There is conflicting evidence as to effectiveness (Brockhaus 1990, Elger 1990, Devor 1990, Haker and Lundeberg 1990).