Cynthia R. Long

A Randomized Controlled Trial Comparing 2 Types of Spinal Manipulation and Minimal Conservative Medical Care for Adults 55 Years and Older With Subacute or Chronic Low Back Pain

OBJECTIVE Chiropractic care is used by many older patients for low back pain (LBP), but there are no published results of randomized trials examining spinal manipulation (SM) for older adults. The purpose of this study was to compare the effects of 2 biomechanically distinct forms of SM and minimal conservative medical care (MCMC) for participants at least 55 years old with subacute or chronic nonradicular LBP. METHODS Randomized controlled trial. The primary outcome variable was low back-related disability assessed with the 24-item Roland Morris Disability questionnaire at 3, 6, 12, and 24 weeks. Participants were randomly allocated to 6 weeks of care including 12 visits of either high-velocity, low-amplitude (HVLA)-SM, low-velocity, variable-amplitude (LVVA)-SM, or 3 visits of MCMC. RESULTS Two hundred forty participants (105 women and 135 men) ages 63.1 +/- 6.7 years without significant comorbidities. Adjusted mean Roland Morris Disability change scores (95% confidence intervals) from baseline to the end of active care were 2.9 (2.2, 3.6) and 2.7 (2.0, 3.3) in the LVVA-SM and HVLA-SM groups, respectively, and 1.6 (0.5, 2.8) in the MCMC group. There were no significant differences between LVVA-SM and HVLA-SM at any of the end points. The LVVA-SM group had significant improvements in mean functional status ranging from 1.3 to 2.2 points over the MCMC group. There were no serious adverse events associated with any of the interventions. CONCLUSIONS Biomechanically distinct forms of SM did not lead to different outcomes in older LBP patients and both SM procedures were associated with small yet clinically important changes in functional status by the end of treatment for this relatively healthy older population. Participants who received either form of SM had improvements on average in functional status ranging from 1 to 2.2 over those who received MCMC. From an evidence-based care perspective, patient preference and clinical experience should drive how clinicians and patients make the SM procedure decision for this patient population.

Patient-centered outcomes of high-velocity, low-amplitude spinal manipulation for low back pain: A systematic review

Low back pain (LBP) is a well-recognized public health problem with no clear gold standard medical approach to treatment. Thus, those with LBP frequently turn to treatments such as spinal manipulation (SM). Many clinical trials have been conducted to evaluate the efficacy or effectiveness of SM for LBP. The primary objective of this paper was to describe the current literature on patient-centered outcomes following a specific type of commonly used SM, high-velocity low-amplitude (HVLA), in patients with LBP. A systematic search strategy was used to capture all LBP clinical trials of HVLA using our predefined patient-centered outcomes: visual analogue scale, numerical pain rating scale, Roland-Morris Disability Questionnaire, and the Oswestry Low Back Pain Disability Index. Of the 1294 articles identified by our search, 38 met our eligibility criteria. Like previous SM for LBP systematic reviews, this review shows a small but consistent treatment effect at least as large as that seen in other conservative methods of care. The heterogeneity and inconsistency in reporting within the studies reviewed makes it difficult to draw definitive conclusions. Future SM studies for LBP would benefit if some of these issues were addressed by the scientific community before further research in this area is conducted.

Adding chiropractic manipulative therapy to standard medical care for patients with acute low back pain: results of a pragmatic randomized comparative effectiveness study.

Study Design. Randomized controlled trial. Objective. To assess changes in pain levels and physical functioning in response to standard medical care (SMC) versus SMC plus chiropractic manipulative therapy (CMT) for the treatment of low back pain (LBP) among 18 to 35-year-old active-duty military personnel. Summary of Background Data. LBP is common, costly, and a significant cause of long-term sick leave and work loss. Many different interventions are available, but there exists no consensus on the best approach. One intervention often used is manipulative therapy. Current evidence from randomized controlled trials demonstrates that manipulative therapy may be as effective as other conservative treatments of LBP, but its appropriate role in the healthcare delivery system has not been established. Methods. Prospective, 2-arm randomized controlled trial pilot study comparing SMC plus CMT with only SMC. The primary outcome measures were changes in back-related pain on the numerical rating scale and physical functioning at 4 weeks on the Roland-Morris Disability Questionnaire and back pain functional scale (BPFS). Results. Mean Roland-Morris Disability Questionnaire scores decreased in both groups during the course of the study, but adjusted mean scores were significantly better in the SMC plus CMT group than in the SMC group at both week 2 (P < 0.001) and week 4 (P = 0.004). Mean numerical rating scale pain scores were also significantly better in the group that received CMT. Adjusted mean back pain functional scale scores were significantly higher (improved) in the SMC plus CMT group than in the SMC group at both week 2 (P < 0.001) and week 4 (P = 0.004). Conclusion. The results of this trial suggest that CMT in conjunction with SMC offers a significant advantage for decreasing pain and improving physical functioning when compared with only standard care, for men and women between 18 and 35 years of age with acute LBP.

Preliminary study of the effects of a placebo chiropractic treatment with sham adjustments

OBJECTIVE To identify aspects of the delivery of placebo chiropractic treatments by using sham adjustments that may cause a treatment effect and that may affect the success of blinding. DESIGN AND SETTING Two-period crossover design in a chiropractic college research clinic. SUBJECTS Eighteen volunteer staff, students, and faculty of the chiropractic college who reported low-back pain within the last 6 months. INTERVENTIONS Flexion-distraction technique was used to perform chiropractic adjustments, and a hand-held instrument (Activator adjusting instrument) with the pressure gauge set on the 0 was used to perform sham adjustments. The treatment period was 2 weeks, with a total of 4 visits. MAIN OUTCOME MEASURES The Visual Analog Scale (VAS) for pain and Global Well-Being Scale (GWBS). RESULTS Although VAS and GWBS scores improved with both treatments, a somewhat greater improvement occurred in most cases with the active treatment. Eight of 14 patients interviewed believed that the placebo had a treatment effect. CONCLUSION This study provided preliminary information that was useful in planning the protocol for a placebo chiropractic treatment in the randomized clinical trial for which it was designed.

Chiropractic Care for Patients Aged 55 Years and Older: Report from a Practice-Based Research Program

OBJECTIVE: To characterize patients aged 55 years and older and features of chiropractic care provided to them.

Vertebral position alters paraspinal muscle spindle responsiveness in the feline spine: effect of positioning duration

Proprioceptive information from paraspinal tissues including muscle contributes to neuromuscular control of the vertebral column. We investigated whether the history of a vertebras position can affect signalling from paraspinal muscle spindles. Single unit recordings were obtained from muscle spindle afferents in the L6 dorsal roots of 30 Nembutal‐anaesthetized cats. Each afferents receptive field was in the intact muscles of the low back. The L6 vertebra was controlled using a displacement‐controlled feedback motor and was held in each of three different conditioning positions for durations of 0, 2, 4, 6 and 8 s. Conditioning positions (1.0–2.2 mm dorsal and ventral relative to an intermediate position) were based upon the displacement that loaded the L6 vertebra to 50–60% of the cats body weight. Following conditioning positions that stretched (hold‐long) and shortened (hold‐short) the spindle, the vertebra was repositioned identically and muscle spindle discharge at rest and to movement was compared with conditioning at the intermediate position. Hold‐short conditioning augmented mean resting spindle discharge by +4.1 to +6.2 impulses s−1; however, the duration of hold‐short did not significantly affect this increase (F4,145= 0.49, P= 0.74). The increase was maintained at the beginning of vertebral movement but quickly returned to baseline. Conversely, hold‐long conditioning significantly diminished mean resting spindle discharge by −2.0 to −16.1 impulses s−1 (F4,145= 11.23, P < 0.001). The relationship between conditioning duration and the diminished resting discharge could be described by a quadratic (F1,145= 9.28, P= 0.003) revealing that the effects of positioning history were fully developed within 2 s of conditioning. In addition, 2 s or greater of hold‐long conditioning significantly diminished spindle discharge to vertebral movement by −5.7 to −10.0 impulses s−1 (F4,145= 11.0, P < 0.001). These effects of vertebral positioning history may be a mechanism whereby spinal biomechanics interacts with the spines proprioceptive system to produce acute effects on neuromuscular control of the vertebral column.

Relationship between Biomechanical Characteristics of Spinal Manipulation and Neural Responses in an Animal Model: Effect of Linear Control of Thrust Displacement versus Force, Thrust Amplitude, Thrust Duration, and Thrust Rate

High velocity low amplitude spinal manipulation (HVLA-SM) is used frequently to treat musculoskeletal complaints. Little is known about the interventions biomechanical characteristics that determine its clinical benefit. Using an animal preparation, we determined how neural activity from lumbar muscle spindles during a lumbar HVLA-SM is affected by the type of thrust control and by the thrusts amplitude, duration, and rate. A mechanical device was used to apply a linear increase in thrust displacement or force and to control thrust duration. Under displacement control, neural responses during the HVLA-SM increased in a fashion graded with thrust amplitude. Under force control neural responses were similar regardless of the thrust amplitude. Decreasing thrust durations at all thrust amplitudes except the smallest thrust displacement had an overall significant effect on increasing muscle spindle activity during the HVLA-SMs. Under force control, spindle responses specifically and significantly increased between thrust durations of 75 and 150 ms suggesting the presence of a threshold value. Thrust velocities greater than 20–30 mm/s and thrust rates greater than 300 N/s tended to maximize the spindle responses. This study provides a basis for considering biomechanical characteristics of an HVLA-SM that should be measured and reported in clinical efficacy studies to help define effective clinical dosages.

Effects of thrust amplitude and duration of high-velocity, low-amplitude spinal manipulation on lumbar muscle spindle responses to vertebral position and movement.

OBJECTIVE Mechanical characteristics of high-velocity, low-amplitude spinal manipulations (HVLA-SMs) can vary. Sustained changes in peripheral neuronal signaling due to altered load transmission to a sensory receptors local mechanical environment are often considered a mechanism contributing to the therapeutic effects of spinal manipulation. The purpose of this study was to determine whether variation in an HVLA-SMs thrust amplitude and duration alters the neural responsiveness of lumbar muscle spindles to either vertebral movement or position. METHODS Anesthetized cats (n = 112) received L6 HVLA-SMs delivered to the spinous process. Cats were divided into 6 cohorts depending upon the peak thrust force (25%, 55%, 85% body weight) or thrust displacement (1, 2, 3 mm) they received. Cats in each cohort received 8 thrust durations (0-250 milliseconds). Afferent discharge from 112 spindles was recorded in response to ramp and hold vertebral movement before and after the manipulation. Changes in mean instantaneous frequency (∆MIF) during the baseline period preceding the ramps (∆MIFresting), during ramp movement (∆MIFmovement), and with the vertebra held in the new position (∆MIFposition) were compared. RESULTS Thrust duration had a small but statistically significant effect on ∆MIFresting at all 6 thrust amplitudes compared with control (0-millisecond thrust duration). The lowest amplitude thrust displacement (1 mm) increased ∆MIFresting at all thrust durations. For all the other thrust displacements and forces, the direction of change in ∆MIFresting was not consistent, and the pattern of change was not systematically related to thrust duration. Regardless of thrust force, displacement, or duration, ∆MIFmovement and ∆MIFposition were not significantly different from control. CONCLUSION Relatively low-amplitude thrust displacements applied during an HVLA-SM produced sustained increases in the resting discharge of paraspinal muscle spindles regardless of the duration over which the thrust was applied. However, regardless of the HVLA-SMs thrust amplitude or duration, the responsiveness of paraspinal muscle spindles to vertebral movement and to a new vertebral position was not affected.

Spinal manipulation and home exercise with advice for subacute and chronic back-related leg pain: A trial with adaptive allocation

Context Few studies evaluate the comparative effectiveness of conservative treatments for back-related leg pain. Contribution This randomized trial, involving 192 adults with subacute or chronic back-related leg pain, compared 12 weeks of home exercise and advice with spinal manipulative therapy plus home exercise and advice. Spinal manipulative therapy with home exercise and advice improved self-reported pain and function outcomes more than exercise and advice alone at 12 weeks, but differences between groups were not present at 52 weeks except for some secondary outcomes. Caution The intervention was not blinded. Implication Spinal manipulative therapy combined with home exercise and advice can improve short-term outcomes in patients with back-related leg pain. The Editors Back-related leg pain (BRLP) is an important symptom commonly associated with pervasive low back pain (LBP) conditions and, despite its socioeconomic effect, has been generally understudied. With poorer prognosis and quality of life, persons with BRLP have greater pain severity and incur more work loss, medication use, surgery, and health-related costs than those with uncomplicated LBP (16). Most patients with BRLP are treated with prescription medications and injections, although little to no evidence supports their use (7, 8). Surgical approaches are also commonly applied, although there is only some evidence for short-term effectiveness compared with less invasive treatments (9). Concerns are mounting about the overuse, costs, and safety of these conventional medical treatments (1018), warranting identification of more conservative treatment options. Spinal manipulative therapy (SMT), exercise, and education promoting self-management are increasingly recommended as low-risk strategies for BRLP (19). Although limited, evidence shows that these conservative approaches can be effective (2026). A recent systematic review by our group showed that SMT is superior to sham SMT for acute BRLP in the short and long term; however, the evidence for subacute and chronic BRLP is inconclusive, and high-quality research is needed to inform clinical and health policy decisions (20). The underlying mechanisms of SMT seem to be multifactorial, including improvement in spinal stiffness, muscle recruitment, and synaptic efficacy of central neurons (27, 28). The purpose of this study was to test the hypothesis that the addition of SMT to home exercise and advice (HEA) would be more effective than HEA alone for patients with subacute and chronic BRLP. Methods Design Overview This pragmatic trial used a parallel design with allocation by minimization and has been described previously (29). Patients were recruited between 2007 and 2010, and follow-up was completed in 2011. Institutional review boards approved the study protocol, and all patients provided written consent. The primary outcomes and most secondary outcomes were self-reported; objective measures were obtained by blinded examiners. There were no important changes to methods after trial commencement. Settings and Patients The trial was conducted at institution-affiliated research clinics at Northwestern Health Sciences University (Minneapolis, Minnesota) and Palmer College of Chiropractic (Davenport, Iowa). Patients were recruited through newspaper advertisements, direct mail, and community posters. Interested patients were initially screened by telephone interviews, followed by 2 in-person baseline evaluation visits. Inclusion criteria were age 21 years or older; BRLP based on Quebec Task Force on Spinal Disorders classifications 2, 3, 4, or 6 (radiating pain into the proximal or distal part of the lower extremity, with or without neurologic signs) (30); BRLP severity of 3 or greater (scale of 0 to 10); a current episode of 4 weeks or more; and a stable prescription medication plan in the previous month. Exclusion criteria were Quebec Task Force on Spinal Disorders classifications of 1, 5, 7, 8, 9, 10, and 11 (pain without radiation into the lower extremities, progressive neurologic deficits, the cauda equina syndrome, spinal fracture, spinal stenosis, surgical lumbar spine fusion, several incidents of lumbar spine surgery, chronic pain syndrome, visceral diseases, compression fractures or metastases, blood clotting disorders, severe osteoporosis, and inflammatory or destructive tissue changes of the spine). Patients could not be receiving ongoing treatment of leg pain or LBP; be pregnant or nursing; have current or pending litigation for workers compensation, disability, or personal injury; be unable to read or comprehend English; or have evidence of substance abuse. Allocation A Web-based program assigned patients to treatment after the second baseline visit using a minimization algorithm based on the Taves method (31), balancing on 7 baseline characteristics previously shown to influence outcomes (3234). Baseline characteristics included age, BRLP duration, neurologic signs, distress, positive straight leg raise, time spent driving a vehicle, and pain aggravation with coughing or sneezing. Patients were assigned in a 1:1 ratio, stratified by site. The allocation algorithm was prepared by the study statistician before enrollment, and its administration was concealed from study personnel. Interventions The intervention protocols were developed and tested in previous pilot studies (32, 33). Both interventions were intended to be pragmatic in nature (for example, modified to patient presentation and needs) and were informed by commonly recommended clinical practices, patient preferences, and promising research evidence (19, 3538). Eleven chiropractors with a minimum of 5 years of practice experience delivered SMT in the SMT plus HEA group. Thirteen providers (7 chiropractors, 5 exercise therapists, and 1 personal trainer) delivered the HEA intervention. When possible, patients worked with the same providers during the 12-week course of care; however, to accommodate patient and provider schedules during the intervention period, providers were trained to comanage patients. Treatment fidelity was facilitated through standardized training, manuals of operation, and clinical documentation forms that were monitored weekly by research staff. SMT Plus HEA Group As many as 20 SMT visits were allowed, each lasting 10 to 20 minutes, including a brief history and examination. Patients assigned to SMT plus HEA also attended 4 HEA visits, as described in the HEA Group section. For SMT visits, the primary focus of treatment was on manual techniques (including high-velocity, low amplitude thrust procedures or low-velocity, variable amplitude mobilization maneuvers to the lumbar vertebral or sacroiliac joints). The specific spinal level treated and the number and frequency of SMT visits were determined by the clinician on the basis of patient-reported symptoms, palpation, and pain provocation tests (39). Adjunct therapies to facilitate SMT were used as needed and included light soft-tissue techniques (that is, active and passive muscle stretching and ischemic compression of tender points) and hot or cold packs. To facilitate adherence to HEA, chiropractors asked about patients adherence, reaffirmed main HEA messages, and answered questions as needed. HEA Group Home exercise and advice were delivered in four 1-hour, one-on-one visits during the 12-week intervention. The main program goals were to provide patients with the tools to manage existing pain, prevent pain recurrences, and facilitate engagement in daily activities. Instruction and practice were provided for positioning and stabilization exercises to enhance mobility and increase trunk endurance. These were individualized to patients lifestyles, clinical characteristics (including positional sensitivities), and fitness levels. Positioning exercises included extension and flexion motion cycles (patients were encouraged to perform 25 repetitions 3 times per day in the lying, standing, or seated position) (33, 40). Stabilization exercises included pelvic tilt, quadruped, bridging, abdominal curl-ups, and side bridging with positional variations appropriate to patients tolerance and abilities (41). Patients were instructed to do 8 to 12 repetitions of each stabilization exercise every other day. Patients were also instructed in methods for developing spine posture awareness related to their activities of daily living, such as lifting, pushing and pulling, sitting, and getting out of bed (42). Information about simple pain-management techniques, including cold, heat, and movement, was also provided. Printed materials were distributed to take home and review. They included instructions of exercises with photos and a modification of the Back in Action book (43), emphasizing movement and restoration of normal function and fitness (35, 44). To facilitate adherence to HEA, providers called or e-mailed patients 3 times (at 1, 4, and 9 weeks) to reaffirm main messages and answer exercise-related questions. Outcomes and Measurements Patients demographic and clinical characteristics were collected at their first baseline visit through self-report questionnaires, histories, and physical examinations. Self-reported outcomes were collected at the baseline visit and at 3, 12, 26, and 52 weeks via questionnaires independent of study personnel influence. Patients were queried in each questionnaire about attempts to influence their responses. The primary outcome measure was patient-rated typical level of leg pain during the past week using an 11-point numerical rating scale, a reliable, valid, and important patient-centered outcome (36, 4547). The primary end points were 12 weeks, which was the end of the intervention phase, and the 52-week follow-up. A complete description of all secondary outcome measures is provided elsewhere (29). The measures reported in this article include LBP, disability measured with the modified RolandMorris Disability Questionnaire (4850), physical and

Neural responses to the mechanical parameters of a high-velocity, low-amplitude spinal manipulation: effect of preload parameters.

OBJECTIVE The purpose of this study was to determine how the preload that precedes a high-velocity, low-amplitude spinal manipulation (HVLA-SM) affects muscle spindle input from lumbar paraspinal muscles both during and after the HVLA-SM. METHODS Primary afferent activity from muscle spindles in lumbar paraspinal muscles were recorded from the L6 dorsal root in anesthetized cats. High-velocity, low-amplitude spinal manipulation of the L6 vertebra was preceded either by no preload or systematic changes in the preload magnitude, duration, and the presence or absence of a downward incisural point. Immediate effects of preload on muscle spindle responses to the HVLA-SM were determined by comparing mean instantaneous discharge frequencies (MIF) during the HVLA-SMs thrust phase with baseline. Longer lasting effects of preload on spindle responses to the HVLA-SM were determined by comparing MIF during slow ramp and hold movement of the L6 vertebra before and after the HVLA-SM. RESULTS The smaller compared with the larger preload magnitude and the longer compared with the shorter preload duration significantly increased (P = .02 and P = .04, respectively) muscle spindle responses during the HVLA-SM thrust. The absence of preload had the greatest effect on the change in MIF. Interactions between preload magnitude, duration, and downward incisural point often produced statistically significant but arguably physiologically modest changes in the passive signaling properties of the muscle spindle after the manipulation. CONCLUSION Because preload parameters in this animal model were shown to affect neural responses to an HVLA-SM, preload characteristics should be taken into consideration when judging this interventions therapeutic benefit in both clinical efficacy studies and in clinical practice.