Global status of chiropractic education research: a scoping review protocol.

OBJECTIVE: The objective of this scoping review is to map the volume and nature (topics, study designs, regions) of chiropractic education research relating to chiropractic learners and programs worldwide. INTRODUCTION: Education of the health workforce is critical to reach population health goals. Chiropractic educational programs are expanding globally; however, the state of chiropractic education research is not known. A better understanding of the volume and nature of chiropractic education research will inform education research priorities and development of chiropractic programs, and assist with preparing a stronger chiropractic workforce to address world health goals. INCLUSION CRITERIA: This scoping review will consider articles that study students, faculty, administration, staff, graduates, and programs in any chiropractic education setting, including graduate, clinical, postgraduate, and specialty training, in any country. Articles on non-educational topics or clinical research will be excluded. METHODS: This review will follow the JBI scoping review methodology and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). The databases to be searched include PubMed, Scopus, CINAHL, Index to Chiropractic Literature, Biblioteca Virtual em Saúde, and Educational Resources Information Center from their inception. All languages will be considered. Two reviewers will independently screen records using predefined eligibility criteria and extract data using tables. Data extracted from eligible articles will include study design, participants, region, and topics. The results will be presented in a narrative summary with data presented in tabular and diagrammatic formats. REVIEW REGISTRATION: Open Science Framework https://osf.io/9b3ap.

Spine-Adjusting Instrument (Impulse®) Attenuates Nociception and Modulates Oxidative Stress Markers in the Spinal Cord and Sciatic Nerve of a Rat Model of Neuropathic Pain.

OBJECTIVE: Oxidative stress plays an important role in neuropathic pain (NP). Spinal manipulative therapy (SMT) can exert beneficial effects on pain outcomes in humans and in animal models. SMT can also modulate oxidative stress markers in both humans and animals. We aimed to determine the effect of Impulse®-assisted SMT (ISMT) on nociception and oxidative stress biomarkers in the spinal cords and sciatic nerves of rats with NP. METHODS: NP was induced by chronic constriction injury (CCI) of the sciatic nerve. Animals were randomly assigned to naive, sham (rats with sciatic nerve exposure but without ligatures), or CCI, with and without ISMT. ISMT was applied onto the skin area corresponding to the spinous process of L4-L5, three times per week for 2 weeks. Mechanical threshold, latency to paw withdrawal in response to thermal stimulus, and oxidative stress biomarkers in the spinal cord and sciatic nerve were the main outcomes evaluated. RESULTS: ISMT significantly increased mechanical threshold and withdrawal latency after CCI. In the spinal cord, ISMT prevented the increase of pro-oxidative superoxide anion generation and hydrogen peroxide levels. Lipid hydroperoxide levels both in the spinal cord and in the sciatic nerve were attenuated by ISMT. Total antioxidant capacity increased in the spinal cords and sciatic nerves of CCI rats with and without ISMT. CCI and ISMT did not significantly change the total thiol content of the spinal cord. CONCLUSIONS: Our findings suggest that reduced oxidative stress in the spinal cord and/or nerve may be an important mechanism underlying a therapeutic effect of SMT to manage NP nonpharmacologically.

Spinal Manipulation Therapy Improves Tactile Allodynia and Peripheral Nerve Functionality and Modulates Blood Oxidative Stress Markers in Rats Exposed to Knee-Joint Immobilization.

OBJECTIVE: The purpose of our study was to evaluate the effect of manually assisted lumbar spinal manipulation therapy on tactile allodynia, peripheral nerve functional recovery, and oxidative markers in rats exposed to knee immobilization-inducing hypersensitivity. METHODS: Tactile allodynia and sciatic, tibial, and peroneal functional indices were assessed before the knee joint immobilization, 24 hours after the knee cast removal, and 24 hours after 3 weeks of lumbar therapy with the Activator Adjusting Instrument, model 4 (AAI 4). Subsequently, the blood was collected from each rat, and oxidative markers such as lipid hydroperoxide levels; nitric oxide metabolites; and superoxide dismutase, catalase, and glutathione peroxidase activities were assessed. RESULTS: The AAI 4 improved the immobilization-induced allodynia and recovered the peripheral nerve functional indices impaired after knee immobilization. Immobilized rats treated with AAI 4 therapy presented a lack of significant changes in lipid hydroperoxides and nitric oxide metabolites in the plasma contrasting with rats that were kept freely in their cages, with no therapy applied, which presented elevated lipid hydroperoxides levels. Also, the antioxidant catalase enzymatic activity decreased in the blood of rats immobilized and treated with AAI 4. CONCLUSION: These results suggest that manually assisted lumbar spinal manipulation therapy modulates systemic oxidative stress, which possibly contributes to the analgesia and recovery of peripheral nerve functionality.

Systemic administration of vitamins C and E attenuates nociception induced by chronic constriction injury of the sciatic nerve in rats.

Antioxidants have been tested to treat neuropathic pain, and α-Tocopherol (vitamin E--vit. E) and ascorbic acid (vitamin C--vit. C) are potent antioxidants. We assessed the effect of intraperitoneal administration of vit. C (30 mg/kg/day) and vit. E (15 mg/kg/day), given alone or in combination, on the mechanical and thermal thresholds and the sciatic functional index (SFI) in rats with chronic constriction injury (CCI) of the sciatic nerve. We also determined the lipid hydroperoxides and total antioxidant capacity (TAC) in the injured sciatic nerve. Further, we assessed the effects of oral administration of vit. C+vit. E (vit. C+E) and of a combination of vit. C+E and gabapentin (100mg/kg/day, i.p.) on the mechanical and thermal thresholds of CCI rats. The vitamins, whether administered orally or i.p., attenuated the reductions in the mechanical and thermal thresholds induced by CCI. The antinociceptive effect was greater with a combination of vit. C+E than with each vitamin given alone. The SFI was also improved in vitamin-treated CCI rats. Co-administration of vit. C+E and gabapentin induced a greater antinociceptive effect than gabapentin alone. No significant change occurred in TAC and lipid hydroperoxide levels, but TAC increased (45%) while lipid hydroperoxides decreased (38%) in the sciatic nerve from vit. C+E-treated CCI rats. Thus, treatment with a combination of vit. C+E was more effective to treat CCI-induced neuropathic pain than vitamins alone, and the antinociceptive effect was greater with co-administration of vit. C+E and gabapentin than with gabapentin alone.

Peripheral oxidative stress blood markers in patients with chronic back or neck pain treated with high-velocity, low-amplitude manipulation.

OBJECTIVE: The purpose of this study was to investigate oxidative-stress parameters in individuals with chronic neck or back pain after 5 weeks of treatment with high-velocity, low-amplitude (HVLA) spinal manipulation. METHODS: Twenty-three individuals aged 38.2 ± 11.7 years with nonspecific chronic neck or back pain verified by the Brazilian Portuguese version of the Chronic Pain Grade, with a sedentary lifestyle, no comorbidities, and not in adjuvant therapy, underwent treatment with HVLA chiropractic manipulation twice weekly for 5 weeks. Therapeutic procedures were carried out by an experienced chiropractor. Blood samples were assessed before and after treatment to determine the activities of the antioxidant enzymes superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx), and the levels of nitric oxide metabolites and lipid hydroperoxides. These blood markers were analyzed by paired Student t test. Differences were considered statistically significant, when P was <.05. RESULTS: There was no change in catalase but an increase in SOD (0.35 ± 0.03 U SOD per milligram of protein vs 0.44 ± 0.04 U SOD per milligram of protein; P < .05) and GPx (7.91 ± 0.61 nmol/min per milligram of protein vs 14.07 ± 1.07 nmol/min per milligram of protein; P < .001) activities after the treatment. The nitric oxide metabolites and the lipid hydroperoxides did not change after treatment. CONCLUSION: High-velocity, low-amplitude spinal manipulation twice weekly for 5 weeks increases the SOD and GPx activities. Previous studies have shown a relationship between pain and oxidative and nitrosative parameters; thus, it is possible that changes in these enzymes might be related to the analgesic effect of HVLA spinal manipulation.

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.

Effect of N-acetylcysteine on the spinal-cord glutathione system and nitric-oxide metabolites in rats with neuropathic pain.

Since N-acetylcysteine (NAC) is a donor of cysteine, we studied the relationship between NAC and concentration of oxidized and reduced glutathione (GSH/GSSG ratio), and glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activities in the lumbosacral spinal cord of rats with chronic constriction injury (CCI) of the sciatic nerve that received NAC (150mg/kg/day, i.p.) or 0.9% saline solution for 3 or 10 days. Hydrogen peroxide (H2O2) and nitric-oxide (NO) metabolites were also measured. Von Frey hair and hot-plate tests showed hyperalgesia at day 1 in CCI rats. Hyperalgesia persisted at all other times in saline-treated CCI rats, but returned to pre-injury values in NAC-treated CCI rats after 3 postoperative days. GST activity and the GSH/GSSG ratio increased in saline-treated CCI rats, while the NAC treatment increased GST and GPx activities at day 10, with no significant change in the GSH/GSSG ratio. NAC treatment did not affect H2O2 levels, but it reduced NO metabolites in CCI rats 3 days after the surgery. Thus, the anti-hyperalgesic effect of NAC appears not to involve its action as a cysteine precursor for GSH synthesis, but involves a decrease in NO.

Assessment of oxidative parameters in rat spinal cord after chronic constriction of the sciatic nerve.

Although reactive oxygen species (ROS) are involved in neuropathic pain, the direct relationship between these species and chronic constriction of sciatic nerve (CCI) has not been studied in spinal cord. Thus, this study induced CCI in rats and these animals were sacrificed 3 and 10 days after the surgical procedure to determine the superoxide dismutase (SOD) and catalase activities, as well as ascorbic acid, hydrogen peroxide (H(2)O(2)) and lipid hydroperoxide levels in lumbosacral spinal cord. Von Frey Hair and hot plate tests were performed to assess the degree of mechanical and thermal hyperalgesia at days 0, 3 and 10. The results showed that CCI significantly induced mechanical and thermal hyperalgesia at days 3 and 10. Parallel there was increase in spinal cord lipid hydroperoxide at days 3 and 10 in rats submitted to CCI. In Sham rats a significant increase in this parameter occurred at day 10. H(2)O(2) decreased at day 10 only in CCI group. SOD activity was decreased in Sham and CCI groups at day 3, while catalase activity was increased in CCI rats at days 3 and 10. Ascorbic acid levels were reduced only in CCI rats at day 3. Although the role of such changes is unclear, many were not specific to neuropathic pain and the differences could be related to different degrees of central sensitization in Sham and CCI rats.

Effect of high-velocity, low-amplitude treatment on superoxide dismutase and glutathione peroxidase activities in erythrocytes from men with neck pain.

OBJECTIVE: This study investigates the analgesic effect of high-velocity, low-amplitude (HVLA) manipulation and antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx) in erythrocytes of men with neck pain. METHODS: Twenty-two men with neck pain of mechanical origin who were aged 20 to 50 years, were nonsmokers, had a sedentary lifestyle, had no comorbidities, and were not in adjuvant therapy underwent 6 sessions of HVLA chiropractic manipulation 3 times a week for 2 weeks. Patients were treated by the same chiropractor and under the same conditions. Blood samples were collected before the beginning of the treatment and at the end of the third and last session. Erythrocytes were separated from blood and then processed to determine SOD and GPx activities. The quadruple visual scale and the Neck Disability Index were used to demonstrate the analgesic effect of treatment. The results were analyzed by repeated-measures analysis of variance followed by Bonferroni posttest. Differences were considered significant when P was less than .05. RESULTS: Despite the tendency to reduction in SOD and increase in GPx activities, there was no significant change after the treatment. CONCLUSION: High-velocity, low-amplitude treatment for 6 sessions in men with neck pain did not affect systemic SOD and GPx activities. Despite the absence of significant changes, this study is important because it is the first to investigate the activities of SOD and GPx in patients with neck pain treated with HVLA spinal manipulation.

Interferential therapy effect on mechanical pain threshold and isometric torque after delayed onset muscle soreness induction in human hamstrings.

This study was undertaken to examine the acute effect of interferential current on mechanical pain threshold and isometric peak torque after delayed onset muscle soreness induction in human hamstrings. Forty-one physically active healthy male volunteers aged 18-33 years were randomly assigned to one of two experimental groups: interferential current group (n = 21) or placebo group (n = 20). Both groups performed a bout of 100 isokinetic eccentric maximal voluntary contractions (10 sets of 10 repetitions) at an angular velocity of 1.05 rad · s(-1) (60° · s(-1)) to induce muscle soreness. On the next day, volunteers received either an interferential current or a placebo application. Treatment was applied for 30 minutes (4 kHz frequency; 125 µs pulse duration; 80-150 Hz bursts). Mechanical pain threshold and isometric peak torque were measured at four different time intervals: prior to induction of muscle soreness, immediately following muscle soreness induction, on the next day after muscle soreness induction, and immediately after the interferential current and placebo application. Both groups showed a reduction in isometric torque (P < 0.001) and pain threshold (P < 0.001) after the eccentric exercise. After treatment, only the interferential current group showed a significant increase in pain threshold (P = 0.002) with no changes in isometric torque. The results indicate that interferential current was effective in increasing hamstrings mechanical pain threshold after eccentric exercise, with no effect on isometric peak torque after treatment.

Effects of high-velocity, low-amplitude manipulation on catalase activity in men with neck pain.

OBJECTIVE: The aim of this study was to identify the influence of high-velocity, low-amplitude (HVLA) manipulation on lipid peroxidation and catalase activity in subjects with neck pain who answered the Neck Disability Index and quadruple visual scale questionnaires. METHODS: Twenty-two men (mean age, 38 years) with neck pain were recruited through radio and newspaper advertisements in the local media. Every patient received 6 sessions of HVLA manipulation, 3 times a week for 2 weeks. Blood samples were drawn from the cubital vein before treatment in the first session and after the third and sixth sessions. The quadruple visual scale was used with the same scheme. The Neck Disability Index questionnaire was applied before the beginning of treatment and after the last session. Catalase activity and lipoperoxidation were measured in erythrocyte samples. RESULTS: Results showed no change in lipid peroxidation. Nevertheless, the catalase activity was increased by HVLA manipulation. The same treatment reduced pain perception and disability in these subjects. CONCLUSION: The present study has shown that catalase activity of the erythrocytes, but not lipoperoxidation, increased after 6 sessions of HVLA manipulation treatment in men with neck pain. The results support the beneficial role of HVLA in the treatment of patients with neck pain.