Effects of Chiropractic Care on Strength, Balance, and Endurance in Active-Duty U.S. Military Personnel with Low Back Pain: A Randomized Controlled Trial.

Objectives: To investigate whether chiropractic care influences strength, balance, and/or endurance in active-duty United States military personnel with low back pain (LBP). Design: This study employed a prospective randomized controlled trial using a pragmatic treatment approach. Participants were randomly allocated to 4 weeks of chiropractic care or to a wait-list control. Interventions: Chiropractic care consisted of spinal manipulation, education, advice, and reassurance. Settings/Location: Naval Air Technical Training Center branch clinic at the Naval Hospital Pensacola Florida. Subjects: One hundred ten active-duty military personnel 18-40 years of age with self-reported LBP. Outcome measures: Isometric pulling strength from a semisquat position was the primary outcome. Secondary outcomes were single-leg balance with eyes open and eyes closed, and trunk muscle endurance using the Biering-Sorensen test. Patient-reported outcomes such as pain severity and disability were also measured. Outcomes were measured at baseline and 4 weeks. Linear mixed-effects regression models over baseline and 4 weeks were used for analysis. Results: Participants had mean age of 30 years (18-40), 17% were female, 33% were non-white, and 86% reported chronic LBP. Mean maximum pulling strength in the chiropractic group increased by 5.08 kgs and decreased by 7.43 kgs in the wait-list group, with a statistically significant difference in mean change between groups (p = 0.003). Statistically significant differences in mean change between groups were also observed in trunk muscle endurance (13.9 sec, p = 0.002) and balance with eyes closed (0.47 sec, p = 0.01), but not in balance with eyes open (1.19 sec, p = 0.43). Differences in mean change between groups were statistically significant in favor of chiropractic for LBP-related disability, pain intensity and interference, and fear-avoidance behavior. Conclusions: Active-duty military personnel receiving chiropractic care exhibited improved strength and endurance, as well as reduced LBP intensity and disability, compared with a wait-list control.

A pilot study of the effect of force feedback training on students learning flexion-distraction chiropractic technique.

OBJECTIVE: We compared traditional training alone and with the addition of force feedback training for learning flexion-distraction chiropractic technique. METHODS: Participants were randomly allocated to two groups (traditional or traditional plus force feedback training). Students' forces were measured before training and after force feedback training. Students rated the helpfulness of the training and the comfort of the force transducer. RESULTS: Thirty-one students were enrolled. Both groups delivered similar forces at baseline. Group 1 students' subsequent force measurements were higher after force feedback training. Group 2 students' forces were unchanged. Group 2 students were trained with force feedback for week 2 of the class, and forces were higher after feedback and similar to those in group 1. Students rated the training as very or somewhat helpful. Students also experienced discomfort as a patient and a student-doctor due to the force transducer that was used. Students who received force feedback training learned to deliver higher forces, which were closer to the forces delivered by experienced doctors of chiropractic. Students who did not receive force feedback continued to deliver lower forces. CONCLUSION: Force feedback helped students deliver forces closer to the desired force level and to learn this delivery faster than students who were not trained with force feedback.

Assessment of chiropractic care on strength, balance, and endurance in active-duty U.S. military personnel with low back pain: a protocol for a randomized controlled trial.

BACKGROUND: Low back pain (LBP) is a common cause of disability among U.S. military personnel. Approximately 20% of all diagnoses resulting in disability discharges are linked to back-related conditions. Because LBP can negatively influence trunk muscle strength, balance, and endurance, the military readiness of active-duty military personnel with LBP is potentially compromised. Chiropractic care may facilitate the strengthening of trunk muscles, the alteration of sensory and motor signaling, and a reduction in pain sensitivity, which may contribute to improving strength, balance, and endurance for individuals with LBP. This trial will assess the effects of chiropractic care on strength, balance, and endurance for active-duty military personnel with LBP. METHODS/DESIGN: This randomized controlled trial will allocate 110 active-duty military service members aged 18-40 with non-surgical acute, subacute, or chronic LBP with pain severity of ≥2/10 within the past 24 h. All study procedures are conducted at a single military treatment facility within the continental United States. Participants are recruited through recruitment materials approved by the institutional review board, such as posters and flyers, as well as through provider referrals. Group assignment occurs through computer-generated random allocation to either the study intervention (chiropractic care) or the control group (waiting list) for a 4-week period. Chiropractic care consists primarily of spinal manipulation at a frequency and duration determined by a chiropractic practitioner. Strength, balance, and endurance outcomes are obtained at baseline and after 4 weeks. The primary outcome is a change between baseline and 4 weeks of peak isometric strength, which is measured by pulling on a bimanual handle in a semi-squat position. Secondary outcomes include balance time during a single-leg standing test and trunk muscle endurance with the Biering-Sorensen test. Patient-reported outcomes include pain severity, disability measured with the Roland Morris Disability Questionnaire, symptom bothersomeness, PROMIS-29, Fear Avoidance Beliefs Questionnaire, expectations of care, physical activity, and global improvement. DISCUSSION: This trial may help inform further research on biological mechanisms related to manual therapies employed by chiropractic practitioners. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02670148 Registered on 1 February 2016.

Development of an attention-touch control for manual cervical distraction: a pilot randomized clinical trial for patients with neck pain.

BACKGROUND: Manual cervical distraction (MCD) is a traction-based therapy performed with a manual contact over the cervical region producing repeating cycles while patients lie prone. This study evaluated a traction force-based minimal intervention for use as an attention-touch control in clinical trials of MCD for patients with chronic neck pain. METHODS: We conducted a mixed-methods, pilot randomized clinical trial in adults with chronic neck pain. Participants were allocated to three traction force ranges of MCD: low force/minimal intervention (0-20 N), medium force (21-50 N), or high force (51-100 N). Clinicians delivered five treatments over two weeks consisting of three sets of five cycles of MCD at the C5 vertebra and occiput. Traction forces were measured at each treatment. Patient-reported outcomes included a pain visual analogue scale (VAS), Neck Disability Index (NDI), Credibility and Expectancy Questionnaire (CEQ), and adverse effects. A qualitative interview evaluated treatment group allocation perceptions. RESULTS: We randomized 48 participants, allocating an average of five each month. Forty-five participants completed the trial with three participants lost to follow-up. Most participants were women (65%) and white (92%) with a mean (SD) age of 46.8 (12.5) years. Mean traction force values were within the prescribed force ranges for each group at the C5 and occiput levels. Neck pain VAS demonstrated a benefit for high traction force MCD compared to the low force group [adjusted mean difference 15.6; 95% confidence interval (CI) 1.6 to 29.7]. Participants in the medium traction force group demonstrated improvements in NDI compared to the low force group (adjusted mean difference 3.0; 95% CI 0.1 to 5.9), as did participants in the high traction force group (adjusted mean difference 2.7; 95% CI -0.1 to 5.6). CEQ favored the high force group. Most low force participants correctly identified their treatment allocation in the qualitative interview. No serious adverse events were documented. CONCLUSIONS: This pilot study demonstrated the feasibility of a clinical trial protocol and the utility of a traction-based, minimal intervention as an attention-touch control for future efficacy trials of MCD for patients with neck pain. TRIAL REGISTRATION: ClinicalTrials.gov NCT01765751 (Registration Date 30 May 2012).

Clinical trial variability: quality control in a randomized clinical trial.

INTRODUCTION: A major issue in clinical trials in manual medicine is treatment variability. The challenge is to insure that the bounded treatment options are both representative of field practitioner behavior and consistent among research clinicians. This investigation assesses the treatment comparability of field practitioners and research clinicians, for a flexion-distraction treatment procedure, as quality control for a randomized clinical trial. METHODS: Using a series of vignettes, we studied the level of agreement of treatment protocols between field clinicians, research clinicians and a reference clinician regarding treatment location, range of motion during treatment, and number of repetitions used within the flexion-distraction protocol. RESULTS: Results indicated that reliability around decision making for anticipated location of spinal treatment was highest regardless of clinician group. For the research clinicians this level of agreement was ICC=0.88. Decision-making for treatment direction was second highest, at kappa=0.64 for the research clinicians. Reliability around the number of repetitions is poor ranging from ICC=0.18 to 0.34 depending on clinician type. DISCUSSION: Understanding the disparity in treatment protocols is of value in the construction and maintenance of quality control in an actual randomized clinical trial setting. More work was recommended in the preparation of clinical trials and the understanding of clinical decision-making because these disparate factors may dramatically impact the generalizability of clinical trial results.

Comparison of posteroanterior spinal stiffness measures to clinical and demographic findings at baseline in patients enrolled in a clinical study of spinal manipulation for low back pain.

OBJECTIVE: A system for measuring posterior-to-anterior spinal stiffness (PAS) was developed for use in clinical trials of manipulation for low back pain (LBP). The current report is an analysis of the baseline PAS data, with particular emphasis on relationships between PAS and clinical and demographic characteristics. METHODS: Posterior-to-anterior spinal stiffness measurements were recorded over the spinous processes of the lumbar spines from patients who had LBP. The system uses electronic sensors to record displacement and force, whereas a human operator provides the force of indentation. Clinical and outcome measures were compared with spinal stiffness. RESULTS: We recruited 192 patients (89 female and 103 male; average age, 40.0 years; SD, 9.4 years). The average Roland-Morris score was 9.7 (SD, 3.2) on a 24-point scale. The Visual Analog Scale pain scores were 55.7 (SD, 20.9) on a 100-mm scale. Stiffness values ranged from 4.16 to 39.68 N/mm (mean, 10.80 N/mm; SD, 3.72 N/mm). Females' lumbar spines were, on the average, 2 N/mm more compliant than males (P < .001). CONCLUSIONS: The PAS system of computer-monitored equipment with human operation performed well in this clinical study of LBP. Spinal stiffness was found to be different between males and females, and age and body mass index were related to PAS. We found no significant relationship between the severity or chronicity of the LBP complaint and spinal stiffness. There was little agreement between the stiff or tender segments identified by the clinicians using palpation and the segment that measured most stiff using the PAS device.

One-year follow-up of a randomized clinical trial comparing flexion distraction with an exercise program for chronic low-back pain.

OBJECTIVE: Flexion distraction is a commonly used form of chiropractic care with chiropractor utilization rates of 58%. However, no previous randomized clinical trial has assessed the effectiveness of this form of care. The objective of this investigation was to compare the pain and disability during the year after active care based on treatment group allocation (Flexion Distraction versus Exercise Program). STUDY DESIGN: Randomized clinical trial, follow-up. SUBJECTS: Two hundred and thirty-five (235) subjects who were previously randomized to either chiropractic care (flexion distraction) or physical therapy (exercise program) within a clinical trial. OUTCOME MEASURES: Subjects were followed for 1 year via mailed questionnaires to assess levels of pain (Visual Analog Scale) and dysfunction (Roland Morris). RESULTS: Study subjects had a decrease in pain and disability after intervention regardless of which group they attended (p < 0.002), however, during the year after care, subjects who received chiropractic care (flexion distraction therapy) had significantly lower pain scores than subjects who received physical therapy (exercise program) (p = 0.02). CONCLUSIONS: In this first trial on flexion distraction care, flexion distraction was found to be more effective in reducing pain for 1 year when compared to a form of physical therapy.

Amount of health care and self-care following a randomized clinical trial comparing flexion-distraction with exercise program for chronic low back pain.

BACKGROUND: Previous clinical trials have assessed the percentage of participants who utilized further health care after a period of conservative care for low back pain, however no chiropractic clinical trial has determined the total amount of care during this time and any differences based on assigned treatment group. The objective of this clinical trial follow-up was to assess if there was a difference in the total number of office visits for low back pain over one year after a four week clinical trial of either a form of physical therapy (Exercise Program) or a form of chiropractic care (Flexion Distraction) for chronic low back pain. METHODS: In this randomized clinical trial follow up study, 195 participants were followed for one year after a four-week period of either a form of chiropractic care (FD) or a form of physical therapy (EP). Weekly structured telephone interview questions regarded visitation of various health care practitioners and the practice of self-care for low back pain. RESULTS: Participants in the physical therapy group demonstrated on average significantly more visits to any health care provider and to a general practitioner during the year after trial care (p < 0.05). No group differences were noted in the number of visits to a chiropractor or physical therapist. Self-care was initiated by nearly every participant in both groups. CONCLUSION: During a one-year follow-up, participants previously randomized to physical therapy attended significantly more health care visits than those participants who received chiropractic care.

Head repositioning errors in normal student volunteers: a possible tool to assess the neck's neuromuscular system.

BACKGROUND: A challenge for practitioners using spinal manipulation is identifying when an intervention is required. It has been recognized that joint pain can interfere with the ability to position body parts accurately and that the recent history of muscle contraction can play a part in that interference. In this study, we tested whether repositioning errors could be induced in a normal population by contraction or shortening of the neck muscles. METHODS: In the experimental protocol, volunteers free of neck problems first found a comfortable neutral head posture with eyes closed. They deconditioned their cervical muscles by moving their heads 5 times in either flexion/extension or lateral flexion and then attempted to return to the same starting position. Two conditioning sequences were interspersed within the task: hold the head in an extended or laterally flexed position for 10 seconds; or hold a 70% maximum voluntary contraction in the same position for 10 seconds. A computer-interfaced electrogoniometer was used to measure head position while a force transducer coupled to an auditory alarm signaled the force of isometric contraction. The difference between the initial and final head orientation was calculated in 3 orthogonal planes. Analysis of variance (1-way ANOVA) with a blocking factor (participants) was used to detect differences in proprioceptive error among the conditioning sequences while controlling for variation between participants. RESULTS: Forty-eight chiropractic students participated: 36 males and 12 females, aged 28.2 +/- 4.8 yrs. During the neck extension test, actively contracting the posterior neck muscles evoked an undershoot of the target position by 2.1 degrees (p <0.001). No differences in repositioning were found during the lateral flexion test. CONCLUSION: The results suggest that the recent history of cervical paraspinal muscle contraction can influence head repositioning in flexion/extension. To our knowledge this is the first time that muscle mechanical history has been shown to influence proprioceptive accuracy in the necks of humans. This finding may be used to elucidate the mechanism behind repositioning errors seen in people with neck pain and could guide development of a clinical test for involvement of paraspinal muscles in cervical pain and dysfunction.

A randomized trial investigating a chiropractic manual placebo: a novel design using standardized forces in the delivery of active and control treatments.

OBJECTIVES: To evaluate the proposed manual placebo in terms of success in blinding patients to treatment group assignment and outcomes between the treatment groups. DESIGN: Randomized controlled trial. SETTING: A chiropractic college research clinic in the midwestern United States. SUBJECTS: One hundred and eleven (111) individuals aged 18 years and over with subacute or chronic lowback pain. INTERVENTIONS: The active treatment consisted of flexion-distraction chiropractic manipulation and trigger point therapy and the control treatment of sham manipulation and effleurage; both groups received eight treatments over a 3-week period. The application of prescribed ranges of biomechanical forces for each treatment was standardized using specialized computerized equipment. "Nontreatment" aspects of the clinical encounter were to be standardized across groups. A primary clinician blinded to treatment assignment provided interpersonal interactions and treating clinicians delivered treatments with a minimum of interaction. OUTCOME MEASURES: The accuracy of the patient's perception of group assignment at visit 4 and the mean change in the Pain Disability Index (PDI) over the treatment period were the primary outcome variables. RESULTS: Patients in the control group were more likely to perceive their treatment assignment accurately than those in the active group (78% versus 54%, respectively). Patients in both treatment groups improved on the PDI and the Roland-Morris Questionnaire; there were no significant differences in improvement between the groups. Age, gender, prior chiropractic experience and expectation of treatment at baseline had no effect on outcomes. CONCLUSIONS: Patients in the control group were not successfully blinded; however, patients' perceptions of treatment group assignment did not significantly affect outcomes. The clinically significant improvement in both groups, independent of patient or clinician expectations, suggests the presence of therapeutic factors common to both groups, other than biomechanical force. Further studies examining other aspects of the clinical encounter, considered separately from biomechanical force, are warranted before arbitrarily designating any intervention as a "placebo."