Effects of side-posture positioning and side-posture adjusting on the lumbar zygapophysial joints as evaluated by magnetic resonance imaging: a before and after study with randomization.

OBJECTIVE: To test the a priori hypothesis that one of the positive mechanisms of action of chiropractic side-posture manipulation (adjusting) of the lumbar spine is to separate, or gap, the zygapophysial (Z) joints. DESIGN: Before and after study with randomization. SETTING: Chiropractic college clinic and magnetic resonance imaging (MRI) facility. PARTICIPANTS: Sixteen healthy student volunteers (8 men and 8 women) ages 22 to 29 years with no history of significant low back pain. Nineteen volunteers were screened, with 3 disqualified from the study. Subjects were randomized into 4 groups, each with 2 men and 2 women. INTERVENTIONS: Lumbar side-posture spinal adjusting (manipulation) and side-posture positioning. MAIN OUTCOME MEASURES: Comparison of anterior to posterior measurements of the Z joints from MRI scans taken before and after side-posture spinal adjusting and before and after side-posture positioning, and a rigorous subjective evaluation protocol of the Z joints by 3 radiologists blinded to the randomized groups. MAIN RESULTS: Observers making measurements were blinded to what group subjects were placed in and whether they were measuring first or second scans; radiologists were blinded to what group subjects were assigned. Differences were found between the groups. Those receiving side-posture spinal adjusting and remaining in side posture showed the greatest increase in gapping (0.7 mm vs 0.0 mm for controls). CONCLUSIONS: Lumbar side-posture spinal adjusting produced increased separation (gapping) of the zygapophysial joints. Side-posture positioning also produced gapping, but less than that seen with lumbar side-posture adjusting. A larger clinical trial should be performed to further define the results of this study.

The holey spine: a summary of the history of scientific investigation of the intervertebral foramina.

The intervertebral foramina (IVFs) are important to all individuals who treat disorders of the spine, but this region is of special historic significance to chiropractors. This is because some of the earliest descriptions of the mechanism of action of chiropratic were related to the IVFs. The history of investigation of the IVFs is very rich spanning time from the fifth century B.C. to the present. Several professions were based upon theories related to the IVFs or upon serious investigations of the IVFs, and the results of other investigations were reported out of proper context in order to criticize chiropractic and other professions. The history of investigation of the IVFs can be divided into three time periods: 1) very early descriptions of neural foramina and the IVFs; )2 discussions of IVFs by developing professions and the studies of the IVFs by Swanberg in the early twentieth century; and 3) studies of the IVFs in the middle and late twentieth century. This paper discusses the major activities of each of these time periods.

Basic science research in chiropractic: the state of the art and recommendations for a research agenda.

A position paper was prepared as background information for participants in the National Workshop to Develop the Chiropractic Workshop Agenda conducted by the Palmer Center for Chiropractic Research, Davenport, Iowa. The paper was revised in light of comments and suggestions at the workshop by participants and by a workgroup composed of basic scientists from within and outside of chiropractic. This final article documents the history of basic science research in chiropractic, and the current state of the art of basic science research conducted since 1975 by chiropractors or investigators at chiropractic institutions in North America. Seed recommendations contained in the working paper for the development of an adequate infrastructure needed to conduct future research and seed recommendations for a future basic science research agenda were also modified and revised by the workgroup participants through a modified nominal group process. The final recommendations contained in this article represent a synthesis of these recommendations and those of the authors.

Comparison of 1.5 Tesla and 0.35 Tesla field strength magnetic resonance imaging scans in the morphometric evaluation of the lumbar intervertebral foramina.

OBJECTIVE: To compare magnetic resonance imaging (MRI) scans obtained from 1.5 Tesla (T) MRI units with scans obtained from 0.35T MRI units in the morphometric evaluation of the lumbar intervertebral foramina (IVF). DESIGN: Three dimensions of lumbar IVFs were measured on a cadaveric lumbar spine by using Vernier calipers. The spine was embedded in gelatin to simulate soft tissue and scanned twice in a 1.5T MRI unit (3-mm and 5-mm slice thicknesses) and once in a 0.35T MRI unit (5-mm slice thickness). Measurements from the scans were made independently by three observers. The results obtained from the two units were compared to the actual IVF size (as measured by calipers) and to one another. RESULTS: The greatest superior-to-inferior distance had the strongest statistically significant correlation to the actual cadaver measurements for both the 0.35T and 1.5T imaging units [r = 0.986 (0.35T); r = 0.985 (1.5T at 3 mm) and r = 0.981 (1.5T at 5 mm); p < .0001 in all cases]. Mean differences and standard errors were minimal between measurements made from MRI scans of both 1.5T and 0.35T units and measurements made directly from the cadaveric spine. CONCLUSION: Both imaging units produced images that accurately depicted the actual size of the IVF. The MRI units of 0.35T field strength produced images of high morphometric accuracy. In addition, the potential for side effects and the operating costs are less with 0.35T units. Therefore, 0.35T MRI units may be a prudent choice as a clinical and research imaging tool in the evaluation of the lumbar IVF.

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.

Volume determinations of the encephalic ventricles with CT and MRI.

The volume of the encephalic ventricles was determined from magnetic resonance imaging (MRI) scans. Since there are many conditions in which the encephalic ventricles become enlarged such as Alzheimer's disease and hydrocephalus, accurate measurement of the ventricles provides a valuable and safe means of aiding the diagnosis of such conditions and also provides important follow-up information in affected patients. The objective was pursued in a three phase study. This paper presents the data obtained from the first phase. This first phase demonstrated the possibility of measuring fluid filled spaces by MRI in three phantom preparations (small, medium, and large "ventricles"). The results were compared with those obtained from computerized tomography (CT) scans of the same preparations. These volumetric calculations were done with the aid of a Calcomp 9,000 digital analyzer programmed to compensate for the scale factor and slice thickness of the images. The phantom study showed that the results obtained from the MRI scans were better than those obtained from the CT scans in measuring the volume of water-filled cavities (ventricles) in gelatin phantoms. The average percent difference between volumes obtained by an imaging procedure compared to the actual volume as determined by water displacement was 15.8% for CT scanning and a more impressive 8.3% for MRI.

Comparison of computerized tomography with magnetic resonance imaging (MRI) in the evaluation of encephalic ventricular volume.

The volume of the encephalic ventricles was determined from computerized tomographic (CT) and magnetic resonance imaging (MRI) scans of seven subjects without apparent pathology and three subjects with enlarged ventricles. Since there are many conditions in which the encephalic ventricles become enlarged such as Alzheimer's disease and hydrocephalus, accurate measurement of these structures provides (1) a valuable and safe means of aiding in the diagnosis of such conditions and (2) important follow-up information on affected patients. This paper presents the data obtained from the second phase of a three phase study. The first phase demonstrated the possibility of measuring fluid filled spaces by MRI in three phantom preparations (small, medium, and large "ventricles"). The results were compared with those obtained from the computerized tomography (CT) scans of the same preparations. This phase of the study compares the volumes obtained from CT scans with those obtained from MRI scans of the same individuals. The volumetric calculations were done with the aid of a Calcomp 9000 digital analyser programmed to compensate for the scale factor and slice thickness of the images. The results obtained from the MRI scans correlated closely with those obtained from the CT scans of the same subjects. The third and final phase of the project is the development of an MRI volumetric data base for the encephalic ventricles using a larger number of subjects.

Evaluation of encephalic ventricular volume from the magnetic resonance imaging scans of thirty-eight human subjects.

Accurate volume determination of the encephalic ventricles is of importance in several clinical conditions, including Alzheimer's presenile dementia, schizophrenia, and benign intracranial hypertension. Previous studies have investigated the accuracy with which magnetic resonance imaging (MRI) can be used in clinical practice to evaluate the encephalic ventricles. However, adequate evaluation of pathological conditions depends on a sufficient amount of morphometric data from normal subjects. To begin establishing this data base for "normal" subjects, we evaluated the MRI scans of 38 subjects found to have no apparent pathology and calculated the ventricular volume in each case by using methods previously developed in our laboratory. The results were then compared with published volumes determined from studies that used either ventricular casts or computerized tomographic scans. The average total ventricular volume for all 38 subjects was 17.4 cm3, while that for males was 16.3 cm3 and that for females was 18.0 cm3. A small but significant correlation was found between age of subject and ventricular volume, with ventricular size increasing with age.