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Biomedical subjects

Deed E Harrison

Publications and source records attributed to Deed E Harrison.

At least 37 records · Page 2Linked to original sources
PubMed2003

Prediction of osteoporotic spinal deformity.

STUDY DESIGN: A biomechanical model was developed from full-spine lateral radiographs to predict osteoporotic spinal deformity in elderly subjects. OBJECTIVE: To investigate the biomechanics of age-related spinal deformity and concomitant height loss associated with vertebral osteoporosis. SUMMARY OF BACKGROUND DATA: Vertebral bone loss and disc degeneration associated with aging causes bone and disc structures to weaken and deform as a result of gravity and postural stresses. METHODS: An anatomically accurate sagittal-plane, upright-posture biomechanical model of the anterior spinal column (C2-S1) was created by digitizing lateral full-spine radiographs of 20 human subjects with a mean height of 176.8 cm and a mean body weight of 76.6 kg. Body weight loads were applied to the model, after which intervertebral disc and vertebral body forces and deformation were computed and the new spine geometry was calculated. The strength and stiffness of the vertebral bodies were reduced according to an osteopenic aging model and modulus reduction algorithm, respectively. RESULTS: The most osteopenic model (L3 F(ult) = 750 N) produced gross deformities of the spine, including anterior wedge-like fracture deformities at T7 and T8. In this model, increases in thoracic kyphosis and decreases in vertebral body height resulted in a 25.2% decrease in spinal height (C2-S1), an 8.6% decrease in total body height, and a 15.1-cm anterior translation of the C2 spine segment centroid. The resulting deformity qualitatively resembled deformities observed in elderly individuals with osteoporotic compression fractures. CONCLUSIONS: These predictions suggest that postural forces are responsible for initiation of osteoporotic spinal deformity in elderly subjects. Vertebral deformities are exacerbated by anterior translation of the upper spinal column, which increases compressive loads in the thoracolumbar region of the spine.

Age Factors↗
PubMed2003

Repeatability over time of posture, radiograph positioning, and radiograph line drawing: an analysis of six control groups.

BACKGROUND: There is debate concerning the repeatability of posture over time, radiograph positioning repeatability, and radiograph line drawing reliability. These ideas seem to negate the use of before-and-after spinal radiographic imaging to detect and correct vertebral subluxations. OBJECTIVE: To review the results of control groups in 6 clinical control trials with before-and-after radiographic measurements taken days, weeks, months, or years apart to accept or reject the hypothesis that radiographic analysis procedures are not repeatable, reliable, or reproducible. DATA SOURCES: Six published control groups from original data. Other data were obtained from searches on MEDLINE, CHIROLARS, MANTIS, and CINAHL on radiographic reliability, posture, and positioning. RESULTS: Comparison of initial and follow-up radiographic data for 6 control groups indicate that measured angles and distances between initial and follow-up radiograph measurements on lateral and anterior to posterior radiographs are not significantly different when utilizing Chiropractic Biophysics radiographic procedures. In 48 out of 50 measurements, the differences between initial and follow-up radiographs are less than 1.5 degrees and 2 mm. These measurements indicate that posture is repeatable, radiographic positioning is repeatable, and radiographic line drawing analysis for spinal displacement is highly reliable. The scientific literature on these topics also indicates the repeatability of posture, radiographic positioning, and radiographic line drawing. CONCLUSIONS: Posture, radiographic positioning, and radiographic line drawing are all very reliable/repeatable. When Chiropractic Biophysics standardized procedures are used, any pre-to-post alignment changes in treatment groups are a result of the treatment procedures applied. These results contradict common claims made by several researchers and clinicians in the indexed literature. Chiropractic radiologic education and publications should reflect the recent literature, provide more support for posture analysis, radiographic positioning, radiographic line drawing analyses, and applications of posture and radiographic procedures for measuring spinal displacement on plain radiographs.

Biomechanical Phenomena↗
PubMed2002

A new 3-point bending traction method for restoring cervical lordosis and cervical manipulation: a nonrandomized clinical controlled trial.

OBJECTIVE: To evaluate a new 3-point bending type of cervical traction. DESIGN: Nonrandomized controlled trial of prospective, consecutive patients compared with control subjects. Follow-up patient data were obtained at 3 and 15(1/2) months, and 8 1/10 months for controls. SETTING: Data were collected at a spine clinic in Nevada. PATIENTS: Volunteer subjects consisted of 30 patients and 24 controls. Subjects had cervicogenic pain (neck pain, headaches, arm pain, and/or numbness). Subjects were included if their Ruth Jackson radiographic stress lines measured less than 25 degrees but were excluded if they had suspected disk herniation or canal stenosis. All subjects completed the first follow-up examinations, and 25 of 30 patients completed the long-term follow-up examination. INTERVENTIONS: Spinal manipulation for pain and a new form of 3-point bending cervical traction to improve lordosis. Cervical manipulation was provided for the first 3 to 4 weeks of treatment. Traction treatment consisted of 3 to 5 sessions per week for 9 +/- 1 weeks. MAIN OUTCOMES MEASURES: Besides pain visual analog scale (VAS) ratings, pre- and posttreatment lateral cervical radiographs were analyzed. RESULTS: Control subjects reported no change in the pain VAS ratings and had no statistically significant change in segmental or global radiographic alignment. For the traction group, VAS ratings were 4.3 pretreatment and 1.6 posttreatment. Traction group radiographic measurements showed statistically significant improvements (P <.008 in all instances of statistical significance), including anterior head weight bearing (improved 6.2mm), Cobb angle at C2-7 (improved 12.1 degrees ), and angle between posterior tangents at C2-7 (improved 14.2 degrees ). For the treatment group, at 15(1/2)-month follow-up, only minimal loss of C2-7 lordosis (3.5 degrees ) was observed. CONCLUSIONS: Sagittal cervical traction with transverse load at midneck (2-way cervical traction) combined with cervical manipulation can improve cervical lordosis in 8 to 10 weeks as indicated by increases in segmental and global cervical alignment. Magnitude of lordosis at C2-7 remained stable at long-term follow-up.

Adult↗
PubMed2002

Changes in sagittal lumbar configuration with a new method of extension traction: nonrandomized clinical controlled trial.

OBJECTIVE: To determine if a new method of lumbar extension traction can increase lordosis in chronic low back pain (LBP) subjects with decreased lordosis. DESIGN: Nonrandomized controlled trial with follow-up at 3 months and 1(1/2) years. SETTING: Primary care spine clinic in Nevada. PATIENTS: Beginning in mid-1998, the first 48 consecutive patients, who met the inclusion criteria of chronic LBP with decreased lordosis and who completed the treatment program were matched for sex, age, height, weight, and pain scores to 30 control subjects with chronic LBP, who received no treatment. INTERVENTIONS: A new form of 3-point bending lumbar extension traction was provided in-office 3 to 4 times a week for 12+/-4 weeks. Per session, traction duration was started at 3 minutes and was increased to a maximum of 20 minutes. For short-term pain relief, torsion lumbar spinal manipulation was provided in the initial 3 weeks. MAIN OUTCOME MEASURES: Pain as measured on a visual analog scale (VAS) and standing lateral lumbar radiographic measurements. RESULTS: Pain scales and radiographic measurements did not change in the control subjects. In the traction group, VAS ratings decreased from mean +/- standard deviation of 4.4+/-1.9 pretreatment to 0.6+/-0.9 posttreatment (P<.001), and radiographic angles (except at T12-L1) showed statistically significant changes. Mean changes were 5.7 degrees at L4-5 (P<.001), 11.3 degrees between posterior tangents on L1 and L5 (P<.001), 9.1 degrees in Cobb angle at T12-S1 (P<.001), 4.6 degrees in pelvic tilt (P<.001), and 4.7 degrees in Ferguson's sacral base angle (P<.001). At long-term follow-up (17(1/2)mo), 34 of the 48 (71%) subjects returned. Improvements in lordosis were maintained in all 34. CONCLUSIONS: This new method of lumbar extension traction is the first nonsurgical rehabilitative procedure to show increases in lumbar lordosis in chronic LBP subjects with hypolordosis. The fact that there was no change in control subjects' lumbar lordosis indicates the stability of the lumbar lordosis and the repeatability of x-ray procedures. Because, on average, chronic LBP patients have hypolordosis, additional randomized trials should be performed to evaluate the clinical significance of restoration of the lumbar lordosis in chronic LBP subjects.

Adult↗
PubMed2002

Reliability and measurement error of the BioTonix video posture evaluation system--Part I: Inanimate objects.

OBJECTIVE: To investigate the reliability, concurrent validity, and error of a new video digitizing system for evaluating posture when applied to inanimate objects. DESIGN: Delayed repeated measures of digital images of inanimate objects. SETTING: University laboratory. METHODS: Digital video images of inanimate objects (5 parallelograms) of different sizes and shapes were obtained with the BioTonix postural evaluation system. Three examiners digitized video images of inanimate objects twice; the second data collection was 1 week after the first set. The objects were digitized with both high- and low-resolution settings of the video screen. The Tonix's measurements were statistically compared with the actual object dimensions. Statistical evaluations of reliability and validity were conducted. RESULTS: For distances, both intraclass and interclass correlation coefficients were very high, 0.99 for the estimate. The low- versus high-resolution settings were comparable for distances. For angles, on the low-resolution setting, both intraclass and interclass correlation coefficients were very high: 0.969 and 0.953. On the high-resolution setting, for angles, both intraclass and interclass coefficients were well above 0.99. The difference of the actual size and the means of the digitized measurements of the means were small: at most 1.5 degrees for angles and 3.3 mm for distances. The standard deviations were small, and the confidence intervals were narrow. CONCLUSIONS: Our results demonstrate that the BioTonix's video system has high degrees of reliability and validity. Thus this system would seem suitable for clinical use in the analysis of posture.

Biomedical Technology↗
PubMed2002

Further reliability analysis of the Harrison radiographic line-drawing methods: crossed ICCs for lateral posterior tangents and modified Risser-Ferguson method on AP views.

OBJECTIVE: To determine whether the newly derived interclass and intraclass correlation coefficients (ICCs)would overstate or understate the results from 2 previously published studies, which used better known ICCs that assume nested factors, and to determine mean absolute differences of observers' measurements for 3 previous studies. STUDY DESIGN: Retrospective analysis of data from 2 blind studies with repeated-measure design. Two newly derived ICCs, appropriate to situations with 3 random factors (patients, examiners, and occasions) that bear a crossed (as opposed to nested) interrelationship, were applied to data from an experiment with random crossed factors. MAIN OUTCOME MEASURES: Observer reliability is determined with ICCs, 95% CIs, and observer error analysis (mean absolute differences of observers' measurements) for angles and distances derived from Harrison's modified Risser-Ferguson line-drawing method on anteroposterior (AP) lumbar and AP cervical radiographic views. Observer error analysis for angles and distances derived from Harrison's posterior tangent method on lateral cervical views was also determined. RESULTS: The majority of ICCs for reliability of line drawing on both AP cervical and AP lumbar radiographs were in the high range; 13 of 16 ICCs were greater than 0.88. The other 3 ICC values (0.61, 0.76, 0.78) concerned determining the sacral base on AP lumbar views. The new ICCs underestimated observer reliability compared with previously published results (intraclass ICCs lower by 0.01-0.02 and interclass ICCs lower by 0.03-0.10). For an error analysis on data from both AP views, the mean absolute differences of observers' measurements were 1.1 degrees to 1.8 degrees for angles and 1.2 mm to 2.3 mm for distances. For the lateral cervical analysis, the observer error was in the interval 0.8 degrees to 3.2 degrees for angles and <1 mm for distances. CONCLUSIONS: The ICCs assuming random crossed factors understate reliability compared with previously published ICC results assuming nested factors. Reliability of the Harrison modified Risser-Ferguson method of line-drawing analysis on AP views is in the high range, with the majority of ICCs >0.88. For both the Harrison modified Risser-Ferguson method on AP views and posterior tangent method on lateral cervical views, the mean absolute differences of observers' measurements are small.

Cervical Vertebrae↗
PubMed2002

Can the thoracic kyphosis be modeled with a simple geometric shape? The results of circular and elliptical modeling in 80 asymptomatic patients.

Many Cobb measurements have been reported at various levels for the thoracic kyphosis, but geometric models of the shape of kyphosis are rare. Thoracic vertebral bodies were digitized on 80 normal lateral full-spine radiographs to obtain the mean thoracic kyphosis. Global and segmental angles were determined. Computer iteration processes passed geometric shapes through the posterior body coordinates of the mean thoracic kyphosis to determine the best fit model in the least squares sense. The kyphosis was closely modeled with ellipses. The T1 and T12 areas tended to be flatter in curvature when compared with T2-T11, indicating these are inflection points. Mean global angles were Cobb(T1-T12) = 44.2 degrees, Cobb(T2-T11) = 39.9 degrees, and Cobb(T3-T10) = 33.3 degrees. The T2-T11 kyphotic region was closely modeled with approximately a 70-degree portion of an ellipse, with minor axis to major axis ratios of 0.6 to 0.72, and with major axis parallel to the posterior body margin of T11.

Adult↗
PubMed2001

How do anterior/posterior translations of the thoracic cage affect the sagittal lumbar spine, pelvic tilt, and thoracic kyphosis?

Anterior and posterior thoracic cage translations in the sagittal plane have not been reported for their range of motion and effects on the lumbar spine and pelvis. Twenty subjects volunteered for full-spine radiography in neutral, anterior, and posterior thoracic cage translation postures in a standing position. While grasping an anterior vertical pole, with hands at elbow level, subjects were instructed on how to translate their thoracic cage without any flexion/extension, utilizing a full-length mirror. On the radiographs, all four vertebral body corners of T1 through S1 and the superior margin of the acetabulum were digitized. Segmental and global angles of thoracic kyphosis, sagittal lumbar curvature, and pelvic flexion/extension in translation postures were compared to alignment in the neutral posture. Using the femur heads as an origin, the mean range of thoracic cage translation, measured as horizontal movement of T12 from neutral posture, was found to be 85.1 mm anterior and 73 mm posterior. In anterior translation, the thoracic kyphosis is hypokyphotic (Cobb T1-T12 reduced by 16 degrees). In posterior translation, the segmental angles at T12-L1 and L1-L2 flexed, creating an "S" shape in the sagittal lumbar spine, while the thoracic kyphosis increased by 10 degrees. Using posterior tangents from L1 to L5 and T12 to S1, and Cobb angles at T12-S1, the lumbar curve reduced slightly (by less than 3.3 degrees for all global angle measurements) in anterior translation and reduced by 7.4 degrees, 5.7 degrees, and 8.1 degrees respectively in posterior thoracic translation. The angle of pelvic tilt (measured as the angle of intersection of a line through posterior-inferior S1 to the superior acetabulum and the horizontal) reduced by a mean of 15.9 degrees, and Ferguson's sacral base angle to horizontal reduced by a mean of 13.1 degrees in posterior translation. In anterior translation, pelvic tilt and Ferguson's sacral base angle increased by 15.1 degrees and 12.8 degrees, respectively. The findings of this study show that thoracic cage anterior/posterior translations cause significant changes in thoracic kyphosis (26 degrees ), lumbar curve, and pelvic tilt. An understanding of this main motion and consequent coupled movements might aid the understanding of spinal injury kinematics and spinal displacement analysis on full spine lateral radiographs of low back pain and spinal disorder populations.

Adult↗
PubMedDate not supplied

Management of a chronic lumbar disk herniation with chiropractic biophysics methods after failed chiropractic manipulative intervention.

OBJECTIVE: To discuss the use of chiropractic biophysics methods in the treatment and rehabilitation of a patient with a chronic disk herniation at the L5-S1 disk, retrolisthesis of L5, and a reduced lumbar lordosis. CLINICAL FEATURES: A 23-year-old woman suffered from chronic unremitting symptoms of lower back pain and left-leg pain. She was treated five years prior, without relief. Diagnosis at that time was low-back pain and lumbar subluxation. Approximately 3 years later, she was evaluated by an orthopedic surgeon. Magnetic resonance imaging showed a moderate posterior disk protrusion at L5-S1 with degeneration. INTERVENTION AND OUTCOME: Chiropractic treatment of this patient consisted of mirror-image chiropractic adjustments, 3-point bending lumbar extension traction, and postural exercises. The patient responded well with a complete resolution of her symptoms and a restoration of her lumbar lordosis. CONCLUSION: This article suggests that successful management of chronic low-back pain symptoms may require a close analysis of a patient's postural deviations and sagittal plane curves. This study suggests that it is possible to restore lumbar lordosis in some cases and this may have an unforeseen benefit to the patient. Further study is warranted into the treatment of chronic low-back pain with chiropractic biophysics methods.

Adult↗
PubMedDate not supplied

Conservative treatment of a patient with previously unresponsive whiplash-associated disorders using clinical biomechanics of posture rehabilitation methods.

OBJECTIVE: To describe the treatment of a patient with chronic whiplash-associated disorders (WADs) previously unresponsive to multiple physical therapy and chiropractic treatments, which resolved following Clinical Biomechanics of Posture (CBP) rehabilitation methods. CLINICAL FEATURES: A 40-year-old man involved in a high-speed rear-impact collision developed chronic WADs including cervicothoracic, shoulder, and arm pain and headache. The patient was diagnosed with a confirmed chip fracture of the C5 vertebra and cervical and thoracic disk herniations. He was treated with traditional chiropractic and physical therapy modalities but experienced only temporary symptomatic reduction and was later given a whole body permanent impairment rating of 33% by an orthopedic surgeon. INTERVENTION AND OUTCOME: The patient was treated with CBP mirror-image cervical spine adjustments, exercise, and traction to reduce forward head posture and cervical kyphosis. A presentation of abnormal head protrusion resolved and cervical kyphosis returned to lordosis posttreatment. His initial neck disability index was 46% and 0% at the end of care. Verbal pain rating scales also improved for neck pain (from 5/10 to 0/10). CONCLUSION: A patient with chronic WADs and abnormal head protrusion, cervical kyphosis, and disk herniation experienced an improvement in symptoms and function after the use of CBP rehabilitation protocols when other traditional chiropractic and physical therapy procedures showed little or no lasting improvement.

Adult↗
PubMedDate not supplied

Determining the relationship between cervical lordosis and neck complaints.

OBJECTIVE: To investigate the presence of a "functionally normal" cervical lordosis and identify if this and the amount of forward head posture are related to neck complaints. METHODS: Using the posterior tangent method, an angle of cervical lordosis was measured from C2 through C7 vertebrae on 277 lateral cervical x-rays. Anterior weight bearing was measured as the horizontal distance of the posterior superior body of the C2 vertebra compared to a vertical line drawn superiorly from the posterior inferior body of the C7 vertebra. The measurements were sorted into 2 groups, cervical complaint and noncervical complaint groups. The data were then partitioned into age by decades, sex, and angle categories. RESULTS: Patients with lordosis of 20 degrees or less were more likely to have cervicogenic symptoms (P < .001). The association between cervical pain and lordosis of 0 degrees or less was significant (P < .0001). The odds that a patient with cervical pain had a lordosis of 0 degrees or less was 18 times greater than for a patient with a noncervical complaint. Patients with cervical pain had less lordosis and this was consistent over all age ranges. Males had larger median cervical lordosis than females (20 degrees vs 14 degrees) (2-sided Mann-Whitney U test, P = .016). When partitioned by age grouping, this trend is significant only in the 40- to 49-year-old range (2-sided Mann-Whitney U test, P < .01). CONCLUSION: We found a statistically significant association between cervical pain and lordosis < 20 degrees and a "clinically normal" range for cervical lordosis of 31 degrees to 40 degrees. Maintenance of a lordosis in the range of 31 degrees to 40 degrees could be a clinical goal for chiropractic treatment.

Adolescent↗
PubMedDate not supplied

Comparison of mechanical force of manually assisted chiropractic adjusting instruments.

OBJECTIVE: To quantify the force-time and force-delivery characteristics of six commonly used handheld chiropractic adjusting devices. METHODS: Four spring-loaded instruments, the Activator Adjusting Instrument; Activator II Adjusting Instrument, Activator III Adjusting Instrument, and Activator IV Adjusting Instrument, and two electromechanical devices, the Harrison Handheld Adjusting Instrument and Neuromechanical Impulse Adjusting Instrument, were applied to a dynamic load cell. A total of 10 force-time histories were obtained at each of three force excursion settings (minimum to maximum) for each of the six adjusting instruments at preload of approximately 20 N. RESULTS: The minimum-to-maximum force excursion settings for the spring-loaded mechanical adjusting instruments produced similar minimum-to-maximum peak forces that were not appreciably different for most excursion settings. The electromechanical adjusting instruments produced short duration ( approximately 2-4 ms), with more linear minimum-to-maximum peak forces. The force-time profile of the electromechanical devices resulted in a more uniform and greater energy dynamic frequency response in comparison to the spring-loaded mechanical adjusting instruments. CONCLUSIONS: The handheld, electromechanical instruments produced substantially larger peak forces and ranges of forces in comparison to the handheld, spring-loaded mechanical devices. The electromechanical instruments produced greater dynamic frequency area ratios than their mechanical counterparts. Knowledge of the force-time history and force-frequency response characteristics of spinal manipulative instruments may provide basic benchmarks and may assist in understanding mechanical responses in the clinical setting.

Benchmarking↗
PubMedDate not supplied

Conservative treatment of a patient with syringomyelia using chiropractic biophysics protocols.

OBJECTIVE: To present a case of a 41-year-old man with syringomyelia and intractable pain and the subsequent reduction of symptoms. CLINICAL FEATURES: This patient acquired a traumatically induced syrinx in his upper cervical spinal cord after he fell approximately 9 feet and landed on his head, upper back, and neck 9 years before presenting for care. He was diagnosed with a spinal cord cyst (syrinx), located at approximately C2 through C4 after magnetic resonance imaging. In 1995, the patient underwent occipitoatlantal decompression surgery, which improved his symptoms for a short time. INTERVENTION AND OUTCOMES: The patient was treated using Clinical Biomechanics of Posture protocol. The patient was seen 26 times over the course of 3 weeks. His scale for pain severity decreased 50% and other subjective complaints decreased. His posture improved based upon pretreatment and posttreatment lateral cervical radiographs, showing a change from a 10 degrees lordosis with midcervical kyphosis to a 30 degrees lordosis. One-year follow-up examination showed stable improvement in the cervical lordosis and pain intensity. CONCLUSION: This case represents a change in subjective and objective measurements after conservative chiropractic care. This case provides an example that structural rehabilitation may have a positive effect on symptoms of a patient with syringomyelia.

Accidental Falls↗
PubMedDate not supplied

Three-dimensional vertebral motions produced by mechanical force spinal manipulation.

OBJECTIVE: The aim of this study was to quantify and compare the 3-dimensional intersegmental motion responses produced by 3 commonly used chiropractic adjusting instruments. METHODS: Six adolescent Merino sheep were examined at the Institute for Medical and Veterinary Science, Adelaide, Australia. In all animals, triaxial accelerometers were attached to intraosseous pins rigidly fixed to the L1 and L2 spinous processes under fluoroscopic guidance. Three handheld mechanical force chiropractic adjusting instruments (Chiropractic Adjusting Tool [CAT], Activator Adjusting Instrument IV [Activator IV], and the Impulse Adjusting Instrument [Impulse]) were used to randomly apply posteroanterior (PA) spinal manipulative thrusts to the spinous process of T12. Three force settings (low, medium, and high) and a fourth setting (Activator IV only) were applied in a randomized repeated measures design. Acceleration responses in adjacent segments (L1 and L2) were recorded at 5 kHz. The multiaxial intersegmental (L1-L2) acceleration and displacement response at each force setting was computed and compared among the 3 devices using a repeated measures analysis of variance (alpha = .05). RESULTS: For all devices, intersegmental motion responses were greatest for axial, followed by PA and medial-lateral (ML) measurement axes for the data examined. Displacements ranged from 0.11 mm (ML axis, Activator IV low setting) to 1.76 mm (PA axis, Impulse high setting). Compared with the mechanical (spring) adjusting instruments (CAT, Activator IV), the electromechanical Impulse produced the most linear increase in both force and intersegmental motion response and resulted in the greatest acceleration and displacement responses (high setting). Significantly larger magnitude intersegmental motion responses were observed for Activator IV vs CAT at the medium and high settings (P < .05). Significantly larger-magnitude PA intersegmental acceleration and displacement responses were consistently observed for Impulse compared with Activator IV and CAT for the high force setting (P < .05). CONCLUSIONS: Larger-magnitude, 3D intersegmental displacement and acceleration responses were observed for spinal manipulative thrusts delivered with Impulse at most force settings and always at the high force setting. Our results indicate that the force-time characteristics of impulsive-type adjusting instruments significantly affects spinal motion and suggests that instruments can and should be tuned to provide optimal force delivery.

Acceleration↗