Biomechanics--review of approaches for performance training in spinal manipulation.

Motor skills development is an inherent part of clinical training in health disciplines. The conscious use of educational theory to ground learning is receiving increasing attention across health care education. There are three distinct, yet overlapping, stages of motor skill learning; the cognitive, the integrative or associative, and the autonomous; in which a contextual framework for learning content may be structured. The learning is associated with a mapping of changes within the central nervous system by the interactive mechanisms of adaptation, use-dependent plasticity and operant reinforcement. Successful skill learning requires a sufficient amount of practice and the implementation of relevant feedback strategies in the form of knowledge of performance (KP) or knowledge of results (KR). There is a natural maturation of skills that may be accelerated by feedback. Several factors contribute to stronger skills development. "Mixture-of-experts" models systematically sequence tasks into logical blocks of theory, practice and student reflection on performance. Feedback should involve both KP and KR that compares performance to a tangible standard. Rehearsals should balance use of simulators and volunteer simulated patients to provide the full range of safe and effective learning opportunities prior to students accepting a role as care givers to the public in any clinical setting.

Application of incremental change strategies in chiropractic and multidisciplinary clinical settings for quality improvement.

Care for low back pain remains a clinical enigma. Its high prevalence and cost to the system warrants attention for improvement. Although, no major recent clinical breakthroughs for resolving back pain have emerged, reducing unnecessary tests, eliminating useless or harmful practices, preventing care dependence, and enhancing coping skills can be useful goals for improving patient outcomes. Quality Improvement (QI) approaches can serve as bridge between clinical intuition and large scale science. Three chiropractic delivery settings including two teaching clinics and one large multidisciplinary spine care center incorporated QI approaches as part of an initiative to improve low back pain care. All clinics were able to implement sustainable process and outcomes improvements.

An analytical model of lumbar motion segment in flexion.

OBJECTIVE: To develop an analytical model of the lumbar motion segment and to determine the following under the application of flexion physiological loads: (1) the force displacement relationships of the lumbar motion segment; (2) the forces in the ligaments, disc, and facet joints; (3) the strains in the ligaments; and (4) the effect of the transection of the ligaments. DESIGN: Computer modeling. SETTING: Spinal Ergonomics and Joint Research Laboratory at The National College of Chiropractic. PROCEDURE: Computer model simulation of external loads and simulation of ligament transection. MEASURES: The following parameters were predicted in flexion by means of a computer model: (1) the load-displacement relationships of the lumbar motion segment; (2) the loads in the ligaments, disc and facet joints; (3) the strains in the ligaments; and (4) the effect of the transection of the ligaments. RESULTS: The load sharing among different ligaments predicted by this model under flexion load suggests that the supraspinous ligament carries the greatest load, followed by the yellow ligament, capsular ligament, intertransverse ligament, and interspinous ligament. The ligament strains indicate that the supraspinous ligament undergoes the maximum increase in length, followed by the interspinous ligament, yellow ligament, capsular ligament, and intertransverse ligament. The transection of ligaments increased the flexibility of the joint, the strains on the rest of the ligaments, the loads on all of the rest of the ligaments, as well as the moment on the disc, but does not significantly affect the compressive load on the disc. CONCLUSIONS: The analytical model predicts results similar to the experimental data on cadaver motion segments reported in the literature under flexion moment loads.

Use of chiropractic manipulation in lumbar rehabilitation.

The beneficial effects of manipulation in relieving symptoms and enhancing spinal flexibility can be a valuable tool in the transition of persons with low back pain into lumbar rehabilitation programs. Manipulation may hasten their entry into active care, or permit them to complete programs that might otherwise be interrupted by symptomatic recurrence. Manipulation science and technical procedures are reviewed as a basis to help understand the utility of properly integrated chiropractic manipulation strategies.

Symptoms of neck artery compromise: case presentations of risk estimate for treatment.

OBJECTIVE: To discuss the use of magnetic resonance angiography (MRA) imaging as a definitive means to assess vascular patency and the relative value of various vertebral artery screening maneuvers. CLINICAL FEATURES: Two female patients suffered head and neck trauma with possible vertebral artery insufficiency. Positive vertebral artery screening tests with consistent symptoms were present in both cases. One patient had a congenitally narrowed vertebral artery, whereas the second had no evidence of vascular anomaly. INTERVENTION AND OUTCOME: Conservative chiropractic management using manipulation and rehabilitation led to favorable outcome in both cases. The patient with vascular compromise received a treatment plan avoiding neck manipulation. The second case received manipulation per clinical indications from neck findings. CONCLUSION: MRA imaging may be more important to critical decision making than are the various vertebral artery screening tests in patients with positional vertigo on combined neck extension and rotation.

Historical perspective. Joseph Janse.

The purpose of this presentation is to acknowledge the pioneering work of a key historical figure who contributed to the available knowledge in anatomy and biomechanics, developed political and social infrastructure to promote the maturation and standardization of chiropractic education, and influenced a paradigmatic shift away from a monocausal belief in the origin of disease. Literature search and archives retrieval were used. Janse was a man with personal intellectual integrity and whose personal commitment was driven by a family experience. Evidence shows that Janse took bold initiatives to influence the chiropractic profession and give it the opportunity to develop as a legitimate healthcare discipline. Janse was a visionary clinical scientist and educator whose 38-year tenure as president of a chiropractic college enabled him to influence the course and development of his profession.

Biomechanical performance of spinal manipulation therapy by newly trained vs. practicing providers: does experience transfer to unfamiliar procedures?

OBJECTIVE: To examine the differences in predefined biomechanical parameters of spinal manipulation using a single method common to the training of both novice and expert manipulators. DESIGN: Analytic Cohort Study. PARTICIPANTS: Fifteen novice manipulators and fifteen experienced physicians provided 2 applications of spinal manipulation therapy (SMT) to 15 healthy, male student volunteers. Assignment of volunteers was randomized, and the order of the first interaction with the manipulators was determined by coin toss and then inverted for the second. INTERVENTION: The bilateral transverse-thenar thoracic maneuver was selected from the diversified system of treatment to be used as the test procedure. Selection was guided by mechanical simplicity. SMT was applied at the physician's discretion to the region of T3-T10. Standard informed consent procedures were followed. MAIN OUTCOME MEASURES: Preload force, rise rate of thrust and thrust force were selected as prospective primary outcome measures. Secondary descriptive measures included impulse, rise time, downward incisural point (DIP), fall time, total force, force components and direction cosines. RESULTS: Both novice and experienced manipulators were familiar with the transverse-thenar procedure, but only three of the experienced manipulators professed common use of it. Mean values for primary outcomes were all higher for the experienced participants; however, no statistically significant differences were found. DISCUSSION: Differences are presumed to exist between novice and experienced manipulators, as evidenced by measurement of arbitrarily selected thoracic and lumbar SMT. However, no systematic differences were found when the manipulators have a similar lack of practice experience specific to the test procedure. These results suggest the importance of regular use in developing skill of performance.

Motions of the head and thorax during neck manipulations.

OBJECTIVE: The purpose of this study was to determine the amplitudes and variations of preload positioning and displacements of the head and thorax during spinal manipulative therapy (SMT) applied to C2. DESIGN: This experimental study measured the biomechanics of SMT applied to C2. SETTING: Biomechanics Laboratory, Mechanical Engineering and Applied Mechanics, University of Michigan and Spinal Ergonomics and Joint Research Laboratory, National College of Chiropractic. PARTICIPANTS: Eighteen healthy volunteers from the University of Michigan and the National College of Chiropractic were manipulated by a total of eight experienced chiropractic physicians licensed in the state in which they participated. INTERVENTION: Sixty-six Direct Break (DB) and twenty-three Rotary Break (RB) diversified procedures were administered to C2. Randomization of the DB was made on two variables, direction and intended load intensities. The RB was administered only from the right by each physician. MAIN OUTCOME MEASURES: Linear and angular displacement time histories for the head and thorax mass centers were monitored during the preload setup of each procedure and the dynamic delivery of the treatment procedures. CONCLUSIONS: DB procedures were found to have sagittally symmetric positioning and displacements as a function of intended direction of the procedure. Both DB and RB methods consisted of preload positioning with head flexion. RB rotation and lateral bending preload positions approached the maximal voluntary ranges of motion for the upper cervical spine. Variations among procedures by one manipulator were approximately the same as for variations among manipulators. Data indicates that SMT procedures can be successfully modified to control amplitude and direction of body segment displacements that arise.

Lymphocyte profiles in patients with chronic low back pain enrolled in a clinical trial.

OBJECTIVE: Our earlier findings suggest that patients with musculoskeletal complaints have lower numbers and percentages of natural killer (NK) cells than asymptomatic subjects. This study examines patient lymphocyte profiles, as a secondary outcome measure, in a trial of manipulative therapies to treat chronic low back pain (LBP) of mechanical origin. DESIGN: The patients were compared in a randomized controlled trial. Baseline measures were collected at the initial visit; all patients were scheduled for 11 treatments in 14 days. Treatment consisted of either a high-force, high-velocity, low-amplitude manipulation procedure; a low-force, high-velocity, low-amplitude procedure or a series of educational lectures on lower back pain. Posttreatment measures were collected at the final treatment session; follow-up measures were obtained 2 wk later. SETTING: The study was conducted at a chiropractic teaching clinic in the suburban Chicago area. PARTICIPANTS: Individuals over 18 were eligible if they were new patients or repeat patients with a 6 month's hiatus, if the chief complaint was LBP of greater than 50 days' duration, if pain was elicited with palpation over one or more of the facet joints from the spinal levels between L1 and S1 and including the sacroiliac joints, and if there was absence of pain referral or if pain referral was only scleratogenous in nature. Criteria for excluding patients included hard neurologic signs, systemic disease potentially affecting the musculoskeletal system, contraindication to spinal manipulation such as osteoporosis, fracture or other bony pathology, or treatment with medication intended to relieve symptoms associated with their LBP. Eligibility was determined by a staff diagnostic team independent of the attending physician. Three hundred sixty-seven of 1,275 consecutive new patients met the eligibility criteria. Of these, 209 participated. These results are for 201 patients from whom flow cytometric data were obtained. OUTCOME MEASURES: Both absolute numbers and percentages of B-lymphocytes, T-lymphocytes, T-Helper (TH), T-Suppressor (TS) and NK lymphocytes were determined. Blood samples were collected at the same time that the primary outcome measures were obtained. Cells were stained with two-color monoclonal antibodies directed against specific cell surface antigens, and each lymphocyte subpopulation was quantified directly from lysed whole blood with a Coulter Epics Profile II flow cytometer. RESULTS: Thirty-five patients dropped out before the follow-up visit and technical problems resulted in the loss of data from 17 more and the exclusion of some subpopulation data. In all, 148 cases were analyzed for B cells, 146 for TH, TS and NK cells and 138 for cells that carried both the NK and TS marker. A one-way analysis of variance revealed no significant differences in the lymphocyte profiles at baseline among the three groups. All subpopulation baseline values were within reported reference ranges for normal adult populations. However, the percentage of NK cells (9.1%) was below the published minimum critical value. A repeated measures analysis of variance was used to determine whether treatment effects changed over time, that is, treatment-time interaction. The cell types for which the interaction tests were at or near statistical significance were: TH cells (p = .0208), total T cell percent (p = .0928) and absolute total T cells (p = .0908). Interaction tests for differences in either percent or absolute counts of B cells, TS cells, or NK cells were not statistically significant. CONCLUSIONS: This is the first report of lymphocyte profiles in patients with diagnosed chronic LBP. Our finding of a lower percentage of NK cells in these patients confirms our earlier finding that patients with musculoskeletal problems have a lower percentage of NK cells than do asymptomatic subjects. However, manipulative therapy was not shown to have a clinically significant effect on either the absolute n

Electrodiagnostic testing in back and extremity pain.

OBJECTIVE: The usefulness of electrodiagnostic testing by the primary care provider is shown in two cases of suspected compression-type neural lesions of the lumbar spine. CLINICAL FEATURES: A 54-yr-old female with acute lumbar spine pain that radiated into the hip and a 26-yr-old male with sharp gluteal pain that radiated into the thigh and ankle were admitted into an inpatient care facility for intensive therapy. Plain film radiographs were obtained initially. In addition, electrodiagnostic testing was performed to evaluate the L5 and S1 nerve roots, which suggested compressive-type lesions. Non-enhanced CT of the lumbar spine was performed and revealed central disk herniation or protrusion in each case. INTERVENTION AND OUTCOME: One patient exhibiting central compression signs of bladder dysfunction was referred for medical intervention. The remaining patient received flexion-distraction type of chiropractic manipulation with physiologic therapeutics and was discharged to outpatient care after 16 days. CONCLUSIONS: Electrodiagnostic testing can provide the primary care provider the data needed to make an informed decision regarding advanced imaging studies and to institute appropriate therapy or to intelligently refer a patient for follow-up.

A comparison of outcome measures for use with back pain patients: results of a feasibility study.

OBJECTIVE: To compare the reliability, validity and change in patient clinical status over time with treatment for six potential outcome questionnaires in a defined population of patients. SETTING: Physician based, multidoctor teaching practice. PATIENTS: Three hundred thirty-five consecutive patients presenting with new complaints were solicited. One hundred eighty-six agreed to participate. INTERVENTIONS: The six questionnaires being studied were administered to each of the participants on three separate occasions. They were: a) prior to clinical evaluation for their chief complaint, b) immediately after clinical evaluation and before treatment and c) 6 wk later. MEASUREMENTS: Each instrument was scored following the prescribed methods of interpretation from the original literature describing it. Results were submitted for analysis by Pearson correlation and two-way analysis of variance as appropriate. MAIN RESULTS: Differences were found in the mean value of the modified Zung with respect to both gender and time. An unexpected drop in patients' somatic perceptions in association with the process of clinical evaluation was found for the Modified Somatic Pain Questionnaire. Overall, the Oswestry and Visual Analogue Pain Scale were the most reliable and responsive to clinical change for musculoskeletal disorders. CONCLUSIONS: This investigation demonstrated substantial differences in the validity and reliability of commonly referenced self-administered instruments for quantifying patient perceptions of pain and disability. The Oswestry and Visual Analogue Pain Scale were both more reliable and valid than other instruments.

The Hmax/Mmax ratio as an outcome measure for acute low back pain.

OBJECTIVE: To evaluate the use of the Hmax/Mmax (H/M) ratio as an outcome measure for acute low back pain and to determine the change of this ratio in acute low back pain patients treated with spinal manipulation. DESIGN: Randomized clinical trial. SETTING: Chiropractic college teaching clinic. PATIENTS: Thirty-six patients with acute low back pain (pain of less than 2 wk duration) were referred by clinicians of the teaching clinic. Eligibility criteria for inclusion into the study consisted of the following: a score of eight or more on the Oswestry questionnaire, 33 mm or greater on a 100-mm visual analog scale, no involvement in litigation related to the low back pain complaint, patient not pregnant and no physical or electrodiagnostic signs of nerve root entrapment. INTERVENTIONS: The patients were randomly assigned to either a treatment or control group. The treatment group (n = 17) received treatment deemed appropriate by the clinician as long as it included a side-lying manipulation to the appropriate level. The control group (n = 19) received detuned ultrasound, application of a cold pack and 15-30 sec of very gentle soft tissue massage. Patients were treated three to five times over a period of 10 days and were subsequently reevaluated. MEASUREMENTS: The Hmax/Mmax ratio was calculated from the results of electrodiagnostic testing of the posterior tibial nerve. Extension/flexion ratio of the trunk musculature, Oswestry score and Visual Analog Scale score were also measured. MAIN RESULTS: The mean difference between H/M ratios pre- and postintervention for the group treated by chiropractic methods was -0.101 on the left and -0.117 on the right. The mean difference for the control group was 0.038 on the left and 0.036 on the right. Although not statistically significant, trends suggest that at the time of final assessment, the group receiving chiropractic care had improved more than the control group. CONCLUSIONS: The H/M ratio was found to be within normal limits in subjects with acute low back pain. The H/M ratio showed greater change in the group which received spinal manipulation, but the change was subtle. The results indicate that the H/M ratio may be of limited value in clinical practice.

The effect of spinal manipulation on pain and prostaglandin levels in women with primary dysmenorrhea.

OBJECTIVE: The primary objectives of this study were to compare the effect of spinal manipulation vs. sham manipulation on a) circulating plasma levels of the prostaglandin F2a metabolite, 15-keto-13,14-dihydroprostaglandin (KDPGF2a), b) perceived abdominal and back pain and c) perceived menstrual distress in women with primary dysmenorrhea. DESIGN: This randomized clinical pilot study investigated the outcome measures before and after either a spinal manipulation treatment (SMT) or a sham manipulation. SETTING: All subjects were treated at the National College Chiropractic clinic, a private chiropractic clinic in the suburban Chicago area. PARTICIPANTS: Forty-five women with a history of primary dysmenorrhea were recruited from the local community. The volunteers ranged in age from 20-49 (mean age = 30.3 yr), and were entered into the study between April 1990 and January 1991. Twenty-four were randomly assigned to the spinal manipulation group and 21 were assigned to the sham group. INTERVENTIONS: Subjects treated with spinal manipulation were placed in a side-lying position with the bottom leg straight and the top leg flexed at the knee and hip. They received a high-velocity, short lever, low-amplitude thrust to all clinically relevant vertebral levels within T10 and L5-S1 and the sacroiliac joints. In the sham manipulation, subjects were placed in a side-lying position with both hips and knees flexed. Their manipulation consisted of a similar thrust administered to the midline base of the sacrum. OUTCOME MEASURES: Perceived abdominal and back pain were measured with a visual analog scale, and menstrual distress was measured with the Menstrual Distress Questionnaire. Both were administered 15 min before and 60 min after treatment. Blood samples were collected by venipuncture for the determination of plasma levels of KDPGF2a at the same times. The plasma was then assayed for KDPGF2a by radioimmunoassay. RESULTS: Analysis of covariance and paired Student's t tests were used for the statistical evaluation. Immediately after treatment, the perception of pain and the level of menstrual distress were significantly reduced by SMT. This reduction was associated with a significant reduction in plasma levels of KDGPF2a in the SMT group. A significant and similar reduction in plasma KDPGF2a also occurred in the sham group, indicating that a placebo effect was associated with a single sham intervention. CONCLUSIONS: This randomized pilot study suggests that SMT may be an effective and safe nonpharmacological alternative for relieving the pain and distress of primary dysmenorrhea. However, the large change in KDPGF2a observed in both treatment groups clearly indicates that further studies with more subjects, studied over a longer time frame, are needed to resolve the question of a placebo effect.

Enhanced neutrophil respiratory burst as a biological marker for manipulation forces: duration of the effect and association with substance P and tumor necrosis factor.

A critical need in assessing the clinical utility of manipulative therapy for back pain is the identification of biological changes associated with the forces applied by spinal manipulation. Such changes could then serve as markers for both sham treatment and manipulation. We determined the priming of polymorphonuclear neutrophils for an enhanced respiratory burst and its duration, the priming of mononuclear cells for enhanced endotoxin-stimulated tumor necrosis factor production and plasma levels of substance P following a single thoracic spine manipulation. There was a significant difference in the respiratory burst of polymorphonuclear neutrophils in response to a particulate challenge, depending on the time of blood sample collection. The response of polymorphonuclear neutrophils isolated from blood collected 15 min after manipulation was significantly higher than the response of cells isolated from blood collected 15 min before and 30 and 45 min after manipulation. Mononuclear cells were also primed for enhanced endotoxin-stimulated tumor necrosis factor production by spinal manipulation. Both of these priming effects were accompanied by a slight, but significant elevation in plasma substance P. The mean manipulation force associated with these biological effects was 878 +/- 99 N. These biological effects may provide a means of monitoring the delivery of both sham and manipulative treatment and, therefore, provide a crucial tool for understanding the efficacy of manipulative therapy.

Differences in treatment history with manipulation for acute, subacute, chronic and recurrent spine pain.

Preference for treatment protocols used in the care of spine disorders are based more upon clinical impressions than upon systematic study of the pathology or treatment efficacy. As social emphasis moves to cost containment strategies, quantitative data is necessary to give guidance for rational policy decisions. This study sets a description of the clinical experience obtained in a group practice, teaching clinic engaged in management of spine disorders. The same subjects were separately reported as being broadly representative of those seen in private using a cash payment policy. Clinical characteristics were quantified on 241 patients. A total of 149 volunteered to complete follow up evaluations. The total number of treatment sessions were tallied to case resolution on all 241 patients and were evaluated by stratifying them according to chronicity of the chief complaint. The range of treatment for all cases was 1-22. Chronic complaints required the most care, with a mean of 8.2 sessions (F = 2.833, p = .014). Thoracic disorders required approximately half the care as lordotic spine regions (F = 2.372, p = .04). No differences were observed based upon descriptive classifications of entrapment, mechanical or muscular pain. All but 25 cases reached resolution well within 6 wk, requiring a mean of 3.8 (range 1-11) additional treatment sessions.

Studies on the biomechanical effect of a spinal adjustment.

Manual treatment of spinal disorders is perhaps the most well-studied remedy for spine-related disorders. Clinical description and controlled studies provide only limited advances in knowledge because so little is known scientifically about manual treatment methods or the disorders to which they are directed. The common factor for all manual methods is that they apply an external load to the spine and its surrounding tissues. Merging of efforts by basic scientists, engineers and clinician-scientists can resolve some of the underlying scientific ambiguity surrounding these issues. This report reviews the seminal efforts in biomechanics that are emerging to describe and understand the treatment, the spinal disorder for which it is used and the physiological effects of the treatment.

Enhanced phagocytic cell respiratory burst induced by spinal manipulation: potential role of substance P.

The effect of spinal manipulation on the respiratory burst of polymorphonuclear neutrophils (PMN) and monocytes from treated adults was measured by zymosan-stimulated chemiluminescence (CL). Peripheral blood was collected 15 min before and 15 min after treatment (sham manipulation, thoracic spine manipulation, or soft tissue manipulation), the cells were isolated, challenged with a standardized, opsonized luminol-containing suspension of zymosan, and monitored for CL. Plasma from two subsets of subjects was radioimmunoassayed for Substance P (SP). PMN were also preincubated with SP in vitro over the dose range 5 x 10(-12) M to 5 x 10(-8) M and the CL response monitored. The CL responses of both PMN and monocytes from subjects who received spinal manipulation were significantly higher after than before treatment, and significantly higher than the response in sham or soft-tissue treated subjects. Measurement of the force applied by sham and spinal manipulation suggested a force threshold for the enhancement of the CL response. Plasma levels of SP before and after treatment in sham treated subjects did not differ significantly; however, elevated plasma SP was observed in subjects after spinal manipulation. Preincubation of PMN with 1 x 10(-11) M, 5 x 10(-11) M or 1 x 10(-10) M SP in vitro primed PMN for an enhanced respiratory burst when the cells were subsequently challenged.