Beneficial effects of manually assisted chiropractic adjusting instrument in a rabbit model of osteoarthritis.

Osteoarthritis (OA) is a degenerative disease characterized by injury of all joint tissues. Our previous study showed that in experimental osteoporosis, chiropractic manipulation (CM) exerts protective effects on bone. We here assessed whether CM might ameliorate OA by improving subchondral bone sclerosis, cartilage integrity and synovitis. Male New-Zealand rabbits underwent knee surgery to induce OA by anterior cruciate ligament injury. CM was performed using the chiropractic instrument ActivatorV 3 times/week for 8 weeks as follows: force 2 setting was applied to the tibial tubercle of the rabbit right hind limb (TM-OA), whereas the corresponding left hind limb received a false manipulation (FM-OA) consisting of ActivatorV firing in the air and slightly touching the tibial tubercle. After sacrifice, subchondral bone integrity was assessed in the tibiae by microCT and histology. Cartilage damage and synovitis were estimated by Mankin's and Krenn's scores, respectively, and histological techniques. Bone mineral density and content in both cortical and trabecular compartments of subchondral bone decreased in OA rabbits compared to controls, but partially reversed in the TM-OA group. Trabecular bone parameters in the latter group also showed a significant improvement compared to FM-OA group. Moreover RANKL, OPG, ALP and TRAP protein expression in subchondral bone significantly decreased in TM-OA rabbits with respect to FM-OA group. CM was associated with lower Mankin's and Krenn's scores and macrophage infiltrate together with a decreased protein expression of pro-inflammatory, fibrotic and angiogenic factors, in TM-OA rabbits with respect to FM-OA. Our results suggest that CM may mitigate OA progression by improving subchondral bone as well as cartilage and synovial membrane status.

Low back pain: a major global problem for which the chiropractic profession needs to take more care.

An important series of papers have been published in the Lancet. These papers provide a comprehensive update for the major global problem of low back pain, and the challenges that low back pain presents to healthcare practitioners and policy makers. Chiropractors are well placed to reduce the burden of low back pain, but not all that chiropractors do is supported by robust, contemporary evidence. This commentary summarises the Lancet articles. We also make suggestions for how the chiropractic profession should most effectively help people with low back pain by implementing practices supported by high quality evidence.

Testing a strength and conditioning program to prevent common manipulative technique training injuries in chiropractic students: a study protocol for a randomised controlled trial.

Background: Spinal manipulation is the primary therapy utilised by chiropractors in the management of their patients. The skills required may feel foreign to chiropractic students as they need strength and endurance in movement patterns they may not have otherwise been exposed to. This may lead to injury while learning manipulative techniques. It is plausible to suggest that the implementation of a strength and conditioning program early in a practitioner's career could reduce the incidence and progression of injuries. The study aims to test the effectiveness of a strength and conditioning program in reducing the risk of chiropractic students' acquiring injuries while learning the skill of spinal manipulation. Methods: This study will involve a prospective cohort of chiropractic students who are currently learning manual therapy at an undergraduate level. Participants will be eligible for inclusion if they are enrolled in 3rd or 4th-year chiropractic manual therapy units at Murdoch University chiropractic course. The intervention group will follow a 12-week strength and conditioning program comprised of preventative exercises that address each body region previously identified as being prone to injury. The control group will complete a 12-week walking program. The primary outcome is injury rate, measured via a short questionnaire. The secondary outcome will be strength, measured via submaximal strength tests. Discussion: The prescribed exercises are aimed at improving the strength and endurance of those muscle groups involved in commonly taught manual therapy tasks. The resistance bands have been chosen as they are inexpensive, simple to implement for the purposes of the study, and acceptably safe. A video format was selected to allow ease of access for participants, provide a detailed description and a visual representation of the exercises to be performed. A questionnaire was designed as a means to assess the influence of the strength and conditioning program on injury rate and the impact this may have on the students' ability to continue practicing. The International Physical Activity Questionnaire has been chosen to measure the participants level of activity before beginning the exercise program. Conclusion: This research protocol will be the first large-scale study to investigate the effectiveness of a strength and conditioning program to reduce injuries within chiropractic students learning manual therapy. Trial registration: Australia New Zealand Clinical Trials Registry (ACTRN12617001638325p).

Chiropractic treatment including instrument-assisted manipulation for non-specific dizziness and neck pain in community-dwelling older people: a feasibility randomised sham-controlled trial.

Background: Dizziness in older people is a risk factor for falls. Neck pain is associated with dizziness and responds favourably to neck manipulation. However, it is unknown if chiropractic intervention including instrument-assisted manipulation of the neck in older people with neck pain can also improve dizziness. Methods: This parallel two-arm pilot trial was conducted in Melbourne, Australia over nine months (October 2015 to June 2016). Participants aged 65-85 years, with self-reported chronic neck pain and dizziness, were recruited from the general public through advertisements in local community newspapers and via Facebook. Participants were randomised using a permuted block method to one of two groups: 1) Activator II™-instrument-assisted cervical and thoracic spine manipulation plus a combination of: light massage; mobilisation; range of motion exercises; and home advice about the application of heat, or 2) Sham-Activator II™-instrument-assisted manipulation (set to zero impulse) plus gentle touch of cervical and thoracic spinal regions. Participants were blinded to group allocation. The interventions were delivered weekly for four weeks. Assessments were conducted one week pre- and post-intervention. Clinical outcomes were assessed blindly and included: dizziness (dizziness handicap inventory [DHI]); neck pain (neck disability index [NDI]); self-reported concerns of falling; mood; physical function; and treatment satisfaction. Feasibility outcomes included recruitment rates, compliance with intervention and outcome assessment, study location, success of blinding, costs and harms. Results: Out of 162 enquiries, 24 participants were screened as eligible and randomised to either the chiropractic (n = 13) or sham (n = 11) intervention group. Compliance was satisfactory with only two participants lost to follow up; thus, post-intervention data for 12 chiropractic intervention and 10 sham intervention participants were analysed. Blinding was similar between groups. Mild harms of increased spinal pain or headaches were reported by 6 participants. Costs amounted to AUD$2635 per participant. The data showed a trend favouring the chiropractic group in terms of clinically-significant improvements in both NDI and DHI scores. Sample sizes of n = 150 or n = 222 for dizziness or neck pain disability as the primary outcome measure, respectively, would be needed for a fully powered trial. Conclusions: Recruitment of participants in this setting was difficult and expensive. However, a larger trial may be feasible at a specialised dizziness clinic within a rehabilitation setting. Compliance was acceptable and the outcome measures used were well accepted and responsive. Trial registration: Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12613000653763. Registered 13 June 2013.Trial funding: Foundation for Chiropractic Research and Postgraduate Education (Denmark).

Evidence on the Ability of a Pneumatic Decompression Belt to Restore Spinal Height Following an Acute Bout of Exercise.

OBJECTIVE: The purpose of this study was to evaluate the ability of a pneumatic decompression belt to restore spinal height lost following an acute bout of exercise that induced compression. METHODS: This study implemented a test-retest repeated measures design in which twelve participants (male = 10, female = 2) age, 21.5 ± 1.0 years; height, 179.0 ± 7.70 cm; weight, 84.0 ±11.5 kg; were recruited from a university population and acted as their own control. All participants were healthy with no previous history of disabling back pain, and were frequent weight trainers. A stadiometer was used to measure spinal height at baseline, then following an acute bout of exercise and then again following the intervention (use of a pneumatic decompression belt for 20 minutes) or control (lying supine for 20 minutes). A 2-way repeated measures ANOVA was performed on the change in spinal height in order to evaluate differences between measurement phases and intervention conditions. RESULTS: The use of the decompression belt increased spinal height gain (4.3 ± 3.0 mm) significantly more than the control condition (1.8 ± 1.2 mm) following an acute bout of weightlifting exercises known to elicit high compressive loads on the lumbar spine. CONCLUSION: The pneumatic decompression belt restored spinal height faster than a non-belt wearing condition in young healthy asymptomatic participants.

Evaluation of peak force of a manually operated chiropractic adjusting instrument with an adapter for use in animals.

OBJECTIVE: This study was designed to assess the peak force of a manually operated chiropractic adjusting instrument, the Activator Adjusting Instrument 4 (AAI 4), with an adapter for use in animals, which has a 3- to 4-fold smaller contact surface area than the original rubber tip. METHODS: Peak force was determined by thrusting the AAI 4 with the adapter or the original rubber tip onto a load cell. First, the AAI 4 was applied perpendicularly by a doctor of chiropractic onto the load cell. Then, the AAI 4 was fixed in a rigid framework and applied to the load cell. This procedure was done to prevent any load on the load cell before the thrust impulse. In 2 situations, trials were performed with the AAI 4 at all force settings (settings I, II, III, and IV, minimum to maximum, respectively). A total of 50000 samples per second over a period of 3 seconds were collected. RESULTS: In 2 experimental protocols, the use of the adapter in the AAI 4 increased the peak force only with setting I. The new value was around 80% of the maximum value found for the AAI 4. Nevertheless, the peak force values of the AAI 4 with the adapter and with the original rubber tip in setting IV were similar. CONCLUSION: The adapter effectively determines the maximum peak force value at force setting I of AAI 4.

Introducing the external link model for studying spine fixation and misalignment: part 2, Biomechanical features.

OBJECTIVES: The purpose of this study was to characterize intervertebral stiffness and alignment changes in the external link model and evaluate it as an experimental mimic for studying the chiropractic subluxation. METHOD: A controlled test-retest design was used to evaluate rats with spine segments linked in 3 alignment configurations and controls that were never linked. Dorsal-to-ventral spine stiffness was measured with a load platform, and flexion/extension misalignment was assessed on lateral radiographs obtained with a spine extension jig. Descriptive statistics were computed for study groups, and multiple linear regression models were used to examine all potential explanatory variables for the response variables "stiffness" and "joint position." RESULTS: Rats tested with links in place had significantly higher dorsal-to-ventral stiffness in the neutral configuration than rats in the flexed configuration. This difference remained after the links were removed. Stiffness after link removal was greater for longer linked periods. Surprisingly, stiffness after link removal was also greater with longer unlinked periods. Longer linked periods also produced greater misalignments during forced spine extension testing. Although link configuration was not a statistically significant predictor of misalignments, longer times after link removal did produce greater misalignments. CONCLUSIONS: This study suggests that the external link model can be a valuable tool for studying the effects of spine fixation and misalignment, 2 cardinal features of what has been historically described as the chiropractic subluxation. Significant residual stiffness and misalignment remained after the links were removed. The progressive course of this lesion is consistent with subluxation theory and clinical chiropractic experience.

Introducing the external link model for studying spine fixation and misalignment: part 1--need, rationale, and applications.

This is the first article in a series introducing a new animal model, the External Link Model that we propose will allow researchers to produce and study spine lesions with the cardinal biomechanical features of the chiropractic subluxation: fixation (hypomobility) and misalignment.

Three-dimensional vertebral motions produced by mechanical force spinal manipulation.

OBJECTIVE: The aim of this study was to quantify and compare the 3-dimensional intersegmental motion responses produced by 3 commonly used chiropractic adjusting instruments. METHODS: Six adolescent Merino sheep were examined at the Institute for Medical and Veterinary Science, Adelaide, Australia. In all animals, triaxial accelerometers were attached to intraosseous pins rigidly fixed to the L1 and L2 spinous processes under fluoroscopic guidance. Three handheld mechanical force chiropractic adjusting instruments (Chiropractic Adjusting Tool [CAT], Activator Adjusting Instrument IV [Activator IV], and the Impulse Adjusting Instrument [Impulse]) were used to randomly apply posteroanterior (PA) spinal manipulative thrusts to the spinous process of T12. Three force settings (low, medium, and high) and a fourth setting (Activator IV only) were applied in a randomized repeated measures design. Acceleration responses in adjacent segments (L1 and L2) were recorded at 5 kHz. The multiaxial intersegmental (L1-L2) acceleration and displacement response at each force setting was computed and compared among the 3 devices using a repeated measures analysis of variance (alpha = .05). RESULTS: For all devices, intersegmental motion responses were greatest for axial, followed by PA and medial-lateral (ML) measurement axes for the data examined. Displacements ranged from 0.11 mm (ML axis, Activator IV low setting) to 1.76 mm (PA axis, Impulse high setting). Compared with the mechanical (spring) adjusting instruments (CAT, Activator IV), the electromechanical Impulse produced the most linear increase in both force and intersegmental motion response and resulted in the greatest acceleration and displacement responses (high setting). Significantly larger magnitude intersegmental motion responses were observed for Activator IV vs CAT at the medium and high settings (P < .05). Significantly larger-magnitude PA intersegmental acceleration and displacement responses were consistently observed for Impulse compared with Activator IV and CAT for the high force setting (P < .05). CONCLUSIONS: Larger-magnitude, 3D intersegmental displacement and acceleration responses were observed for spinal manipulative thrusts delivered with Impulse at most force settings and always at the high force setting. Our results indicate that the force-time characteristics of impulsive-type adjusting instruments significantly affects spinal motion and suggests that instruments can and should be tuned to provide optimal force delivery.

Chiropractic: history and overview of theories and methods.

Chiropractic is one of the most controversial and poorly defined healthcare professions with recognition and licensure in the United States. Chiropractic was started by D. D. Palmer, a magnetic healer who formulated the vertebral subluxation theory. The profession was developed by his son, B. J. Palmer. Although the definition of chiropractic as a method of correcting vertebral subluxations to restore and maintain health is questionable, spinal manipulation is of value in the treatment of some types of back pain. The chiropractic profession is still based on the vertebral subluxation theory, and has the confusing image of a back specialty capable of treating a broad scope of health problems. Despite opposition to use of spinal manipulation as a method of treating a broad scope of health problems (as opposed to the generally accepted use of manipulation in the treatment of back pain), chiropractors seek support as primary care providers in alternative medicine. It is essential to understand the theories, philosophies, and methods of chiropractic for an objective evaluation.

Comparison of mechanical force of manually assisted chiropractic adjusting instruments.

OBJECTIVE: To quantify the force-time and force-delivery characteristics of six commonly used handheld chiropractic adjusting devices. METHODS: Four spring-loaded instruments, the Activator Adjusting Instrument; Activator II Adjusting Instrument, Activator III Adjusting Instrument, and Activator IV Adjusting Instrument, and two electromechanical devices, the Harrison Handheld Adjusting Instrument and Neuromechanical Impulse Adjusting Instrument, were applied to a dynamic load cell. A total of 10 force-time histories were obtained at each of three force excursion settings (minimum to maximum) for each of the six adjusting instruments at preload of approximately 20 N. RESULTS: The minimum-to-maximum force excursion settings for the spring-loaded mechanical adjusting instruments produced similar minimum-to-maximum peak forces that were not appreciably different for most excursion settings. The electromechanical adjusting instruments produced short duration ( approximately 2-4 ms), with more linear minimum-to-maximum peak forces. The force-time profile of the electromechanical devices resulted in a more uniform and greater energy dynamic frequency response in comparison to the spring-loaded mechanical adjusting instruments. CONCLUSIONS: The handheld, electromechanical instruments produced substantially larger peak forces and ranges of forces in comparison to the handheld, spring-loaded mechanical devices. The electromechanical instruments produced greater dynamic frequency area ratios than their mechanical counterparts. Knowledge of the force-time history and force-frequency response characteristics of spinal manipulative instruments may provide basic benchmarks and may assist in understanding mechanical responses in the clinical setting.

Status of activator methods chiropractic technique, theory, and practice.

OBJECTIVE: To provide an historical overview, description, synthesis, and critique of the Activator Adjusting Instrument (AAI) and Activator Methods Chiropractic Technique of clinical assessment. METHODS: Online resources were searched including Index to Chiropractic Literature, EBSCO Online, MANTIS, CHIROLARS, CINAHL, eJournals, Ovid, MDConsult, Lane Catalog, SU Catalog, and Pubmed. Relevant peer-reviewed studies, commentaries, and reviews were selected. Studies fell into 2 major content areas: instrument adjusting and the analysis system for therapy application. Studies were categorized by research content type: biomechanical, neurophysiological, and clinical. Each study was reviewed in terms of contribution to knowledge and critiqued with regard to quality. DISCUSSION: More than 100 studies related to the AAI and the technique were found, including studies on the instrument's mechanical effects, and a few studies on clinical efficacy. With regard to the analysis, there is evidence for good reliability on prone leg-length assessment, but to date, there is only 1 study evaluating the Activator Methods Chiropractic Technique analysis. CONCLUSION: A body of basic science and clinical research has been generated on the AAI since its first peer-reviewed publication in 1986. The Activator analysis may be a clinically useful tool, but its ultimate scientific validation requires testing using sophisticated research models in the areas of neurophysiology, biomechanics, and statistical analysis.

Treatment of a case of subacute lumbar compartment syndrome using the Graston technique.

OBJECTIVE: To discuss subacute lumbar compartment syndrome and its treatment using a soft tissue mobilization technique. CLINICAL FEATURES: A patient presented with low back pain related to exercise combined with prolonged flexion posture. The symptoms were relieved with rest and lumbar extension. The patient had restrictive lumbar fascia in flexion and rotation and no neurological deficits. INTERVENTION AND OUTCOME: The restrictive lumbar posterior fascial layers and adjoining restrictive fascia (thoracic, gluteal, hamstring) were treated with a form of instrument-assisted soft tissue mobilization called the Graston technique. Restoration of fascial extensibility and resolution of the complaint occurred after 6 treatment visits. CONCLUSIONS: The posterior spinal fascial compartments may be responsible for intermittent lower back pain. Functional clinical tests can be employed to determine whether the involved fascia is abnormally restrictive. Treatment directed at the restrictive fascia using this soft tissue technique may result in improved fascial functional testing and reduction of symptoms.

Manual discrimination capability when only viscosity is varied in viscoelastic stiffness stimuli.

BACKGROUND: Training manual therapists in the judgment of spinal stiffness traditionally requires the spines of human volunteers. Presenting the range of stiffness values representative of spines requires both time and resources. When investigating the ability of therapists to judge spinal stiffness, several studies have therefore utilized spine analogues, nonbiological devices designed to present either purely elastic stimuli or viscoelastic stimuli with unknown relative contributions of elastic and viscous components. Previous research has suggested that the viscous component of stiffness is more difficult to judge. OBJECTIVE: This study determined for each subject the just-noticeable difference, or discrimination threshold, for manual judgment of viscous stiffness against a constant elastic and friction background. DESIGN: This psychophysical study utilized the Weber fraction as a measure of the ability of subjects to discriminate between viscoelastic stiffness stimuli. METHODS: Twenty-five subjects with both physiotherapy and lay backgrounds volunteered to participate in the study. Stiffness stimuli were generated by a device incorporating a fluid-filled plunger and a spring, with only the amount of viscous stiffness being manipulated by the experimenter. The method of constant stimuli was used to estimate the just-discriminable change in viscous stiffness, and results were expressed as a percentage of the base stiffness or Weber fraction. RESULTS: The mean Weber fraction for manual judgments of viscous stiffness was 14.7%. For 13 of the subjects who had previously participated in elastic stiffness discrimination studies, the Weber fraction for viscous stimuli was significantly greater than that for elastic stimuli. CONCLUSION: The significantly higher Weber fraction for viscous stiffness perception compared with that for pure elastic stiffness suggests that the poor reliability of manual judgments of spinal stiffness may be due to the difficulty in judging the viscous stiffness component.

Forces applied during manual therapy to patients with low back pain.

BACKGROUND: To date, there is little information available regarding the forces used during mobilization treatment of patients with low back pain (LBP). OBJECTIVE: This study measured such forces and investigated whether the force characteristics could be predicted on the basis of physical therapist and patient characteristics. SUBJECTS: Ten physical therapists applied a central posteroanterior (PA) mobilization treatment to 80 patients with LBP, providing data on treatment of 123 lumbar levels. METHODS: Physical therapists were required to treat their patients while the patients lay on an instrumented couch. This couch has been shown to be highly accurate in its measurement of force in 3 directions (error <2%) and has demonstrated high test-retest reliability (ICC [2, 1], 99% CI = 0.99-1.00). The forces applied by the physical therapists were recorded over a 10-second period. Data on the characteristics of the physical therapists and patients were collected by means of questionnaires. RESULTS: The force used by physical therapists related not only to patient characteristics but also to physical therapist characteristics. Interestingly, current pain intensity and nature of symptoms did not affect the forces used. The overall patterns of the force characteristics were generally consistent with previous studies performed in asymptomatic subjects. However, the magnitude of the force applied and the frequency of each grade used in the present study are relatively higher than in earlier studies. CONCLUSION: These preliminary data provide some useful quantitative information about the forces used during mobilization treatment of patients with LBP. Also, the force characteristics described here may provide useful data for both teaching and research in manual therapy.

Chiropractic treatment of postsurgical neck syndrome with mechanical force, manually assisted short-lever spinal adjustments.

OBJECTIVE: To describe a case of postsurgical neck pain, after multiple spinal surgeries, that was successfully treated by chiropractic intervention with instrumental adjustment of the cervical spine. CLINICAL FEATURES: A 35-year-old woman had chronic neck pain for over 5 years after two separate surgeries of the cervical spine: a diskectomy at C3/4 and a fusion at C5/6. Surgeries were performed 6 months apart in an attempt to resolve persistent neck pain and spasm of the cervical musculature. Neither surgery was effective in relieving the patient's pain. Five years after the second surgery, a third surgery was recommended by the patient's physicians to alleviate the chronic pain. The patient sought chiropractic evaluation of her condition to avoid further surgical intervention. INTERVENTION AND OUTCOME: The patient was treated with conservative instrumental chiropractic manipulation, consisting of mechanical force, manually assisted short-lever spinal adjustments rendered with an Activator Adjusting Instrument (AAI) II. She comfortably tolerated the treatment and responded favorably to this therapy. All chronic symptoms had resolved within 30 days of instituting the chiropractic instrumental adjustments with an AAI. More interestingly, longitudinal examination over the next 2 years showed that the patient experienced no residual effects or further recurrences of her previous chronic problem after her initial course of chiropractic care. CONCLUSION: Chiropractic treatment of postsurgical neck syndrome may be effectively treated, in certain cases, by mechanical force, manually assisted adjusting procedures with an AAI. The use of instrumental adjustment methodology may provide chiropractic physicians with an effective alternative to manual manipulation in those cases in which the patient's surgical history or presenting symptoms make forceful manipulation of the spine, particularly performed at end range, inappropriate. This approach may be contemplated by physicians faced with managing this type of condition. Further study should be made in this regard, in an academic research setting, to determine the safest and most effective approaches to managing postsurgical patients in a chiropractic setting.