Changes in Spinal Height After Manual Axial Traction or Side Lying: A Clinical Measure of Intervertebral Disc Hydration Using Stadiometry

OBJECTIVES: The purpose of this study was to determine the immediate effects of a manual therapy technique consisting of axial traction compared with side lying on increased spine height after sustained loading. METHODS: Twenty-one asymptomatic participants were included. Participants either received manual therapy technique consisting of manual axial traction force for 2 consecutive rounds of 3 minutes or sustained side lying for 10 minutes. Spine height was measured using a commercially available stadiometer. Spinal height change was determined from measurements taken after loaded walking and measurements taken after manual therapy. A paired t test was performed to determine if a manual therapy technique consisting of axial traction increased spinal height after a period of spinal loading. RESULTS: A significant increase in height was found after both manual therapy technique and sustained side lying (P < .0001). The mean height gain was 8.60 mm using 3-dimensional axial separation. CONCLUSION: This study is an initial attempt at evaluating the biomechanical effects of manual therapy technique consisting of axial traction. Both manual axial traction force and sustained side-lying position were equally effective for short-term change in spine height after a loaded walking protocol among healthy asymptomatic individuals. This study protocol may help to inform future studies that evaluate spine height after loading.

Morphometric changes of the cervical intervertebral foramen: A comparative analysis of pre-manipulative positioning and physiological axial rotation.

BACKGROUND: Cervical foraminal impingement has been described as a source of radicular pain. Clinical tests and head motions have been reported for affecting the intervertebral foramen (IVF) dimensions. Although manual approaches are proposed in the management of cervical radiculopathy, their influence on the foraminal dimensions remains unclear. OBJECTIVES: To investigate the influence of pre-manipulative positioning versus cervical axial rotation on the foraminal dimensions of the lower cervical spine. METHODS: Thirty asymptomatic volunteers underwent CT scan imaging in neutral position and axial rotation or pre-manipulative positioning. The manipulation task was performed at C4-C5 following a multiple components procedure. 3D kinematics and IVF (height, width and area) were computed for each cervical segment. RESULTS: The results showed that foraminal changes are dependent on motion types and cervical levels. With reference to head rotation, IVF opening occurred on the ipsilateral side during pre-manipulative positioning while axial rotation involved the contralateral side. Regardless of the side considered, magnitudes of opening were similar between both attitudes while narrowing was lower at the target and adjacent levels during the pre-manipulative positioning. Some associations between segmental motion and IVF changes were observed for the target level and the overlying level. CONCLUSIONS: The present study demonstrated that pre-manipulative positioning targeting C4-C5 modified IVF dimensions differently than the passive axial rotation. The findings suggest that techniques which incorporate combined movement positioning influence segmental motion and IVF dimensions differently at the target segment, compared to unconstrained rotation. Further investigations are needed to determine the clinical outcomes of such an approach.

Changes in spinal height following sustained lumbar flexion and extension postures: a clinical measure of intervertebral disc hydration using stadiometry.

BACKGROUND: Decreased intervertebral disc height can result in diminished load carrying capacity of the spinal segment. Clinical means of assessing postures able to rehydrate the discs were investigated. OBJECTIVE: The purposes of this study were 3-fold: (1) to determine if our test protocol using a commercially available stadiometer demonstrated findings consistent with prior laboratory-based protocols; (2) to determine if hyperextension in the prone position and trunk flexion in the supine position caused increased spine height after sustained loading; and (3) to compare the effects of hyperextension in the prone position and trunk flexion in the supine position on spine height changes after a period of sustained loading. METHODS: This study used a pretest, posttest crossover design. Ten women and 11 men (mean age, 24 +/- 2.6 years) participated. Subjects held either 10 minutes of hyperextension in the prone position or 10 minutes of trunk flexion in the supine position in the recovery phase. Spine height was measured using a commercially available stadiometer. Spinal height change was determined from measurements taken after loaded sitting and measurements taken after hyperextension in the prone position and trunk flexion in the supine position. RESULTS: A 1-sample t test indicated no significant difference existed between our mean height change after 5 minutes of sitting and previously published validated findings. A paired t test indicated significant increase in height after both supine flexion and prone extension lying (P< .0001). The mean height gain was 3.11 mm using prone extension and 3.19 mm using the supine flexion protocol. A paired t test indicated no significant difference between these 2 recovery positions (P = .927). CONCLUSION: The stadiometer measurement protocol demonstrated that hyperextension in the prone position and trunk flexion in the supine position were easily effective positions for the temporary recovery of spine height after sustained loading. These findings lay the foundation for future research into the viscoelastic creep properties of the intervertebral disk under loading and therapeutic conditions.

Torsion-induced pressure distribution changes in human intervertebral discs: an in vitro study.

STUDY DESIGN: Biomechanical testing of human cadaveric lumbar specimens was performed to evaluate the effects of torsional torque on intradiscal pressure and disc height. OBJECTIVE: Evaluate the effects of small torsion torques on intradiscal pressure and disc height in human lumbar specimens. SUMMARY OF BACKGROUND DATA: Nuclear depressurization in addition to an instantaneous disc height increase were found in previous porcine research when small (<2 degrees) axial vertebral rotations were applied. If applicable to human spines, this phenomenon may support spinal manipulation for the relief of low back pain. METHODS: Six human lumbar cadaveric functional spine units (FSU) were loaded in the neutral position with 600 N axial compression. Intranuclear pressure measurements were then obtained at 0, 0.5, 1.0, and 2.0 Nm of torsion. Posterior elements were removed and measurements were repeated for the disc body unit (DBU). RESULTS: There was no statistically significant difference in nuclear pressure or intervertebral disc height with different torsion torques among or between the FSUs and DBUs. However, a disc height increase ranging from 0.13 mm to 0.16 mm occurred with the insertion of a 1.85-mm diameter pressure probe cannula. CONCLUSIONS: Small torsion torques showed no significant difference in intradiscal pressures or disc heights. This is an unlikely mechanism for the perceived benefits of spinal manipulation.

Dimensions of the lumbar intervertebral foramina as determined from the sagittal plane magnetic resonance imaging scans of 95 normal subjects.

OBJECTIVES: This was a 2-part study. Part 1 evaluated the reliability of measurements of the intervertebral foramina (IVF) from magnetic resonance imaging (MRI) scans, and part 2 developed a morphometric database of IVF dimensions from normal living subjects. DESIGN: Part 1 was a blinded reliability study using 7 observers, and part 2 developed a morphometric database using 2 teams of 3 observers, all blinded to the results of each other. SUBJECTS: Ninety-five normal subjects (46 women, 49 men) were stratified by age (range 14-84 years, average 38.8 years). OUTCOME MEASURES: Part 1: Interclass correlation coefficients (ICCs) were calculated for intraobserver and interobserver reliability for 3 dimensions of the lumbar IVFs. Part 2: A database was developed using the same measures. In addition, the relationships between IVF dimensions and age, height, weight, sex, and left versus right sides of subjects were evaluated. RESULTS: Part 1: All ICCs were very high (> 0.94). Part 2: 8550 measurements were made, and a morphometric database of 95 subjects, stratified by age and sex, was completed. Differences in IVF size associated with age, height, weight, sex, and side were described. CONCLUSIONS: Measurements taken from MRI scans of IVFs were performed reliably. The morphometric database and IVF relationships should aid clinicians and researchers in evaluating patients with suspected foraminal stenosis and help further investigate IVF pathology and treatment of such pathology.

Lumbosacral transitional segments: classification, prevalence, and effect on disk height.

OBJECTIVE: To determine the rate of lumbosacral transitional segments among chiropractic practice settings and to determine if this anomaly would affect the height of the lumbosacral disk. STUDY DESIGN: Retrospective review of radiographs. SETTING: Los Angeles College of Chiropractic outpatient clinic and a private chiropractic office. SAMPLES: A total of 20 lumbar series with lumbosacral transitional segments from a private chiropractic office, 47 lumbar series with lumbosacral transitional segments, and 60 age- and sex-matched control series from a college clinic. RESULTS: A total of 2.3% of 882 lumbar series at the private chiropractic office and 6.5% of 786 lumbar series at the Whittier Health Center showed lumbosacral transitional segments of types II, III, or IV. The L5-S1 intervertebral disk height was significantly smaller in patients with lumbosacral transitional segments compared with those without (ie, 11% vs 19% of total lumbar disk height, respectively). When bilateral bony fusion of L5 to the sacrum was present, the L5-S1 disk height was significantly smaller than that without bony fusion (ie, 8% vs. 12% to 14% of total lumbar disk height, respectively). CONCLUSIONS: We conclude that the rate of occurrence of lumbosacral transitional segments is low in chiropractic practice. In the presence of lumbosacral transitional segments, especially when there was bony fusion, the lumbosacral intervertebral disk was significantly narrower than the upper lumbar disks, which should not be considered as disk degeneration or displacement. The type of lumbosacral transitional segment present also showed a significant effect on the height of the lumbosacral disk.