Biomedical subjects

Jason W Haas

Publications and source records attributed to Jason W Haas.

11 recordsLinked to original sources

PubMed2006

Radiographic pseudoscoliosis in healthy male subjects following voluntary lateral translation (side glide) of the thoracic spine.

OBJECTIVE: To determine projected Cobb angles associated with trunk list (side shift) posture, hypothesizing that the side shift "scoliotic" curvature would be similar to true scoliotic curvature in the early stages. DESIGN: Anteroposterior (AP) radiographs of volunteers in neutral, in left, and right lateral translations of the thoracic cage (trunk list) were digitized. SETTING: Computer laboratory. PARTICIPANTS: Fifteen healthy male volunteers. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Cobb and Risser-Ferguson angles determined from digitizing vertebral body corners from T12 to L5 on 51 AP lumbar radiographs. RESULTS: Using the horizontal displacement of T12 from S1, subjects could translate an average of 54.0 mm to the left and 52.5 mm to the right. The average digitized Cobb T12-L5 angle produced for the 30 translated postures was 16 degrees. Angles ranged from 2.6 degrees to 27.0 degrees. Risser-Ferguson angles averaged 10 degrees between T12 and L5. Statistical correlations were found between Cobb L1-5 and translation to the left (P=.015), Cobb T12-L5 and translation to the right (P=.024), Risser-Ferguson angle and translation to the left (P=.021), and the lumbosacral angle to the right and trunk translation to the right (P=.027). CONCLUSIONS: During lateral translation of the thorax (trunk list), coupled lumbar lateral flexion resulted in the appearance of a pseudoscoliosis on AP radiographs. For this trunk list posture, Cobb angles are considerable (16 degrees ) and increase as the magnitude of trunk translation increases. Differentiating true structural scoliosis from this pseudoscoliosis would be clinically important. The small coupled axial rotation in trunk list is in contrast to the considerable degree of axial rotation observed in structural idiopathic scoliosis.

Adult↗

PubMed2005

Do sagittal plane anatomical variations (angulation) of the cervical facets and C2 odontoid affect the geometrical configuration of the cervical lordosis?

Anthropometric and statistical evaluation of measurements from digitization of 252 lateral cervical radiographs were used to investigate any correlation between radiographic measurements of cervical lordosis with sagittal plane facet angulation, articular pillar height, and inclination of the C2 odontoid with respect to the body of C2. Some researchers have hypothesized that facet and odontoid architecture variations can cause a reduction in cervical lordosis. To evaluate this hypothesis, the posterior aspect of the C2 dens, vertebral body corners, and superior and inferior facet surfaces of C2-C7 were digitized on 252 lateral cervical X-rays to calculate global angle, segmental angles, dens angle, facet angles, and facet height. No correlation between facet angle, articular pillar height, and cervical curve was found. Similarly, no correlation between the sagittal angle of the dens and any angle of cervical curvature was identified. There was correlation between the global ARA C2-C7 angle and the Cobb angles at C1-C7 (r = 0.71) and C2-C7 (r = 0.82). There was correlation between the global inclination of the atlas vertebral angle (APL) and the Cobb angle at C1-C7 (r = 0.66), Cobb angle at C2-C7 (r = 0.39), ARA C2-C7 (r = 0.42), and anterior translation of C2 compared to C7 (r = -0.46). Because no correlation between cervical facet and odontoid architecture and any segmental or global angle of cervical lordosis was found, conservative and surgical rehabilitative techniques aimed at the reduction of sagittal cervical deformities do not need to account for a patient's architecture of the cervical facets nor odontoid.

Adult↗

PubMed2005

Sagittal skin contour of the cervical spine: interexaminer and intraexaminer reliability of the flexicurve instrument.

OBJECTIVES: To evaluate reliability of a simple instrument, the flexicurve, in determining cervical sagittal skin contour. METHODS: This study obtained repeated random measurements involving 3 investigators and 30 subjects once per day over a 2-day trial period. Thirty normal subjects were examined for cervical spine skin contour twice by 3 separate investigators with a 1-day delay. With subjects in a neutral standing position, investigators placed the flexicurve on the posterior portion of the subject's neck from the external occipital protuberance to the vertebral prominens and traced the flexicurve shape onto paper. The tracings were divided into 6 equal arcs and digitized. Statistical computation was performed on the depth at 5 points, arc angle, and arc radius of curvature. Interexaminer and intraexaminer correlation coefficients (ICCs) were calculated to determine reliability. RESULTS: All interexaminer correlation coefficients were in the poor range (<0.40). For the arc radius, arc angle, depth at top one third, and depth at bottom two thirds, the intraexaminer correlation coefficients were in the poor range. For the 3 deepest depths, the intraexaminer correlation coefficients were in the fair range (0.4-0.50). CONCLUSION: The flexicurve showed marginal reliability with most (12/16) ICCs in the poor range (ICC <0.40) and 4 values in the fair range (0.4 < ICC < 0.5).

Adult↗

PubMed2005

Concurrent validity of flexicurve instrument measurements: sagittal skin contour of the cervical spine compared with lateral cervical radiographic measurements.

OBJECTIVES: The aim of this study was to compare flexicurve surface contour measurements of the cervical spine with radiographic measurements of cervical lordosis. METHODS: One examiner evaluated 96 patients with chronic neck pain in neutral posture using a flexible ruler, flexicurve, to measure sagittal contour of the skin over the cervical spine from the external occipital protuberance to the vertebra prominens. The flexicurve skin contour and neutral lateral radiographs were digitized and compared. The flexicurve and radiographs were categorized into height-length ratio, curve angle, curve depth, sum of depths, modified Ishihara's index, and inverse of radius. Mean values, SDs, mean differences, and limits of agreement were calculated. The differences between flexicurve measurement mean values and x-ray mean values were deemed significant if the lower limit of agreement exceeded 15% of the mean values for the x-ray measurements. RESULTS: For all variables, except the height-length ratio, the mean values of the flexicurve variables differed significantly from the corresponding mean values of the radiographic measurements. All Pearson correlation coefficients were in the very poor range (r < 0.15). CONCLUSION: The flexicurve sagittal skin contour measurement has poor concurrent validity compared with established radiographic measurements of the cervical lordosis. The flexicurve tracings always predicted lordosis, overestimated the lordosis compared with x-ray values, and cannot discriminate between radiographic lordosis, straightened, S curves, and kyphotic alignments of the cervical curve.

Adult↗

PubMed2004

Modeling of the sagittal cervical spine as a method to discriminate hypolordosis: results of elliptical and circular modeling in 72 asymptomatic subjects, 52 acute neck pain subjects, and 70 chronic neck pain subjects.

STUDY DESIGN: Computer analysis of digitized vertebral body corners on lateral cervical radiographs. OBJECTIVES: Using elliptical and circular modeling, the geometric shape of the path of the posterior bodies of C2-C7 was sought in normal, acute pain, and chronic pain subjects. To determine the least squares error per point for paths of geometric shapes, minor axis to major axis elliptical ratios (b/a), Cobb angles, sagittal balance of C2 above C7, and posterior tangent segmental and global angles. SUMMARY OF BACKGROUND DATA: When restricted to cervical lordotic configurations, normal, acute pain, and chronic pain subjects have not been compared for similarities or differences of these parameters. Conventional Cobb angles provide only a comparison of the endplates of the distal vertebrae, while geometric modeling provides the shape of the entire sagittal curves, the orientation of the spine, and segmental angles. METHODS: Radiographs of 72 normal subjects, 52 acute neck pain subjects, and 70 chronic neck pain subjects were digitized. For normal subjects, the inclusion criteria were no kyphotic cervical segments, no cranial-cervical symptoms, and less than +/- 10 mm horizontal displacement of C2 above C7. In pain subjects, inclusion criteria were no kyphotic cervical segments and less than 25 mm of horizontal displacement of C2 above C7. Measurements included segmental angles, global angles of lordosis (C1-C7 and C2-C7), height-to-length ratios, anterior weight bearing, and from modeling, circular center, and radius of curvature. RESULTS: In the normal group, a family of ellipses was found to closely approximate the posterior body margins of C2-C7 with a least squares error of less than 1 mm per vertebral body point. The only ellipse/circle found to include T1, with a least squares error of less than 1 mm, was a circle. Compared with the normal group, the pain group's mean radiographic angles were reduced and the radius of curvature was larger. For normal, acute, and chronic pain groups, the mean angles between posterior tangents on C2-C7 were 34.5 degrees, 28.6 degrees, and 22.0 degrees, C2-C7 Cobb angles were 26.8 degrees, 16.5 degrees, and 12.7 degrees, and radius of curvature were r = 132.8 mm, r = 179 mm, and r = 245.4 mm, respectively. CONCLUSIONS: The mean cervical lordosis for all groups could be closely modeled with a circle. Pain groups had hypolordosis and larger radiuses of curvature compared with the normal group. Circular modeling may be a valuable tool in the discrimination between normal lordosis and hypolordosis in normal and pain subjects.

Acute Disease↗

PubMed2004

A non-randomized clinical control trial of Harrison mirror image methods for correcting trunk list (lateral translations of the thoracic cage) in patients with chronic low back pain.

Spinal trunk list is a common occurrence in clinical practice, but few conservative methods of spinal rehabilitation have been reported. This study is a non-randomized clinical control trial of 63 consecutive retrospective subjects undergoing spinal rehabilitation and 23 prospective volunteer controls. All subjects presented with lateral thoracic-cage-translation posture (trunk list) and chronic low back pain. Initial and follow-up numerical pain rating scales (NRS) and AP lumbar radiographs were obtained after a mean of 11.5 weeks of care (average of 36 visits) for the treatment group and after a mean of 37.5 weeks for the control group. The radiographs were digitized and analyzed for a horizontal displacement of T12 from the second sacral tubercle, verticality of the lumbar spine at the sacral base, and any dextro/levo angle at mid-lumbar spine. Treatment subjects received the Harrison mirror image postural correction methods, which included an opposite trunk-list exercise and a new method of opposite trunk-list traction. Control subjects did not receive spinal rehabilitation therapy, but rather self-managed their back pain. For the treatment group, there were statistically significant improvements (approximately 50%) in all radiographic measurements and a decrease in pain intensity (NRS: 3.0 to 0.8). For the control group, no significant radiographic and NRS differences were found, except in trunk-list displacement of T12 to S1, worsened by 2.4 mm. Mirror image (opposite posture) postural corrective exercises and a new method of trunk-list traction resulted in 50% reduction in trunk list and were associated with nearly resolved pain intensity in this patient population. The findings warrant further study in the conservative treatment of chronic low back pain and spinal disorders.

Adult↗

PubMed2004

Anterior thoracic posture increases thoracolumbar disc loading.

In the absence of external forces, the largest contributor to intervertebral disc (IVD) loads and stresses is trunk muscular activity. The relationship between trunk posture, spine geometry, extensor muscle activity, and the loads and stresses acting on the IVD is not well understood. The objective of this study was to characterize changes in thoracolumbar disc loads and extensor muscle forces following anterior translation of the thoracic spine in the upright posture. Vertebral body geometries (C2 to S1) and the location of the femoral head and acetabulum centroids were obtained by digitizing lateral, full-spine radiographs of 13 men and five women volunteers without previous history of back pain. Two standing, lateral, full-spine radiographic views were obtained for each subject: a neutral-posture lateral radiograph and a radiograph during anterior translation of the thorax relative to the pelvis (while keeping T1 aligned over T12). Extensor muscle loads, and compression and shear stresses acting on the IVDs, were calculated for each posture using a previously validated biomechanical model. Comparing vertebral centroids for the neutral posture to the anterior posture, subjects were able to anterior translate +101.5 mm+/-33.0 mm (C7-hip axis), +81.5 mm+/-39.2 mm (C7-S1) (vertebral centroid of C7 compared with a vertical line through the vertebral centroid of S1), and +58.9 mm+/-19.1 mm (T12-S1). In the anterior translated posture, disc loads and stresses were significantly increased for all levels below T9. Increases in IVD compressive loads and shear loads, and the corresponding stresses, were most marked at the L5-S1 level and L3-L4 level, respectively. The extensor muscle loads required to maintain static equilibrium in the upright posture increased from 147.2 N (mean, neutral posture) to 667.1 N (mean, translated posture) at L5-S1. Compressive loads on the anterior and posterior L5-S1 disc nearly doubled in the anterior translated posture. Anterior translation of the thorax resulted in significantly increased loads and stresses acting on the thoracolumbar spine. This posture is common in lumbar spinal disorders and could contribute to lumbar disc pathologies, progression of L5-S1 spondylolisthesis deformities, and poor outcomes after lumbar spine surgery. In conclusion, anterior trunk translation in the standing subject increases extensor muscle activity and loads and stresses acting on the intervertebral disc in the lower thoracic and lumbar regions.

Biomechanical Phenomena↗

PubMed2004

Cervical kyphosis is a possible link to attention-deficit/hyperactivity disorder.

OBJECTIVE: To discuss the case of a patient who was diagnosed with attention-deficit/hyperactivity disorder (ADHD) by a general practitioner and was treated with chiropractic care. CLINICAL FEATURES: A 5-year-old patient was diagnosed with ADHD and treated by a pediatrician unsuccessfully with methylphenidate (Ritalin), Adderall, and Haldol for 3 years. The patient received 35 chiropractic treatments during the course of 8 weeks. A change from a 12 degrees C2-7 kyphosis to a 32 degrees C2-7 lordosis was observed after treatment. During chiropractic care, the child's facial tics resolved and his behavior vastly improved. After 27 chiropractic visits, the child's pediatrician stated that the child no longer exhibited symptoms of ADHD. The changes in structure and function may be related to the correction of cervical kyphosis. CONCLUSION: The patient experienced significant reduction in symptoms. Additionally, the medical doctor concluded that the reduction in symptoms was significant enough to discontinue the medication. There may be a possible connection that correction of cervical kyphosis in patients with ADHD may produce a desirable clinical outcome.

Attention Deficit Disorder with Hyperactivity↗

PubMed2004

Conservative methods for reducing lateral translation postures of the head: a nonrandomized clinical control trial.

Fifty-one retrospective, consecutive patients were compared to twenty-six prospective volunteer controls in a nonrandomized clinical control trial. Both groups had chronic neck pain and lateral head translation posture. For treatment subjects, beginning and follow-up pain scales and anteroposterior (AP) cervical radiographs were obtained after 12.8 weeks of care (average of 37 visits), while the duration was a mean of 12 months for control subjects. Digitized radiographs were analyzed for Risser-Ferguson angles and a horizontal translation distance of C2 from a vertical line through T3. For treatment, patients received the Harrison mirror-image postural methods, which include mechanically assisted manipulation, opposite head posture exercise, and opposite head translation posture traction. While no significant differences were found in the control group subjects' pain scores and AP radiographic measurements, statistically significant improvements were observed in the treatment group subjects' pain scores and lateral translation displacements of C2 compared to T3 (pretrial score: 13.7 mm, posttrial score: 6.8 mm) and in angle measurements.

Adult↗

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

Increasing the cervical lordosis with chiropractic biophysics seated combined extension-compression and transverse load cervical traction with cervical manipulation: nonrandomized clinical control trial.

BACKGROUND: Cervical lordosis has been shown to be an important outcome of care; however, few conservative methods of rehabilitating sagittal cervical alignment have been reported. OBJECTIVE: To study whether a seated, retracted, extended, and compressed position would cause tension in the anterior cervical ligament, anterior disk, and muscle structures, and thereby restore cervical lordosis or increase the curvature in patients with loss of the cervical lordosis. STUDY DESIGN: Nonrandomized, prospective, clinical control trial. METHODS: Thirty preselected patients, after diagnostic screening for tolerance to cervical extension with compression, were treated for the first 3 weeks of care using cervical manipulation and a new type of cervical extension-compression traction (vertical weight applied to the subject's forehead in the sitting position with a transverse load at the area of kyphosis). Pretreatment and posttreatment Visual Analogue Scale (VAS) pain ratings were compared along with pretreatment and posttreatment lateral cervical radiographs analyzed with the posterior tangent method for changes in alignment. Results are compared to a control group of 33 subjects receiving no treatment and matched for age, sex, weight, height, and pain. RESULTS: Control subjects reported no change in VAS pain ratings and had no statistical significant change in segmental or global cervical alignment on comparative lateral cervical radiographs (difference in all angle mean values < 1.3 degrees ) repeated an average of 8.5 months later. For the traction group, VAS ratings were 4.1 pretreatment and 1.1 posttreatment. On comparative lateral cervical radiographs repeated after an average of 38 visits over 14.6 weeks, 10 angles and 2 distances showed statistically significant improvements, including anterior head weight bearing (mean improvement of 11 mm), Cobb angle at C2-C7 (mean improvement of -13.6 degrees ), and the angle of intersection of the posterior tangents at C2-C7 (mean improvement of 17.9 degrees ). Twenty-one (70%) of the treatment group subjects were followed for an additional 14 months; improvements in cervical lordosis and anterior weight bearing were maintained. CONCLUSIONS: Chiropractic biophysics (CBP) technique's extension-compression 2-way cervical traction combined with spinal manipulation decreased chronic neck pain intensity and improved cervical lordosis in 38 visits over 14.6 weeks, as indicated by increases in segmental and global cervical alignment. Anterior head weight-bearing was reduced by 11 mm; Cobb angles averaged an increase of 13 degrees to 14 degrees; and the angle of intersection of posterior tangents on C2 and C7 averaged 17.9 degrees of improvement.

Adult↗