Segmental lumbar mobility in individuals with low back pain: in vivo assessment during manual and self-imposed motion using dynamic MRI

Regional differences in lumbar spinal posture and the influence of low back pain

Background

Spinal posture is commonly a focus in the assessment and clinical management of low back pain (LBP) patients. However, the link between spinal posture and LBP is not fully understood. Recent evidence suggests that considering regional, rather than total lumbar spine posture is important. The purpose of this study was to determine; if there are regional differences in habitual lumbar spine posture and movement, and if these findings are influenced by LBP.

Methods

One hundred and seventy female undergraduate nursing students, with and without LBP, participated in this cross-sectional study. Lower lumbar (LLx), Upper lumbar (ULx) and total lumbar (TLx) spine angles were measured using an electromagnetic tracking system in static postures and across a range of functional tasks.

Results

Regional differences in lumbar posture and movement were found. Mean LLx posture did not correlate with ULx posture in sitting (r = 0.036, p = 0.638), but showed a moderate inverse correlation with ULx posture in usual standing (r = -0.505, p < 0.001). Regional differences in range of motion from reference postures in sitting and standing were evident. BMI accounted for regional differences found in all sitting and some standing measures. LBP was not associated with differences in regional lumbar spine angles or range of motion, with the exception of maximal backward bending range of motion (F = 5.18, p = 0.007).

Conclusion

This study supports the concept of regional differences within the lumbar spine during common postures and movements. Global lumbar spine kinematics do not reflect regional lumbar spine kinematics, which has implications for interpretation of measures of spinal posture, motion and loading. BMI influenced regional lumbar posture and movement, possibly representing adaptation due to load.

Differences in symmetry of lumbar region passive tissue characteristics between people with and people without low back pain

BACKGROUND

Several investigators have suggested that passive tissue characteristics of the lumbar region may be altered in people with low back pain. Passive stiffness of the lumbar region has been examined during physiological movements in healthy individuals and intersegmental spine mobility and stiffness have been examined in people with and people without low back pain. However, no investigators have examined differences in passive tissue characteristics of the lumbar region during a physiological movement between people with and people without low back pain.

METHODS

Subjects were moved passively through a trunk lateral bending motion on a passive movement device. Lumbar region kinematics were measured with a motion capture system and force required to move the subject was measured with a force transducer. Lumbar region extensibility was defined as the maximum excursion of the lumbar region. Passive elastic energy was defined as the area under the torque-lumbar region angle curve. Differences in lumbar region extensibility and passive elastic energy between sides were examined in people with and people without low back pain (n=41).

FINDINGS

People in the Rotation with Extension low back pain subgroup demonstrated greater asymmetry of passive elastic energy than people without low back pain (P=0.04). There were no differences between groups in symmetry of lumbar region extensibility (P=0.37).

INTERPRETATION

Asymmetry in passive elastic energy of the lumbar region may be related to the low back pain problem in the Rotation with Extension subgroup. The asymmetry in passive elastic energy may be associated with asymmetry of loading on the spine, which has been reported to be a risk factor for low back pain. Thus, it may be important to consider the asymmetry when planning an intervention strategy for people in the Rotation with Extension subgroup.

Relation between changes in posteroanterior stiffness and active range of movement of the cervical spine following manual therapy treatment

STUDY DESIGN

Repeated measures study of active and passive movements in patients with neck pain.

OBJECTIVES

To determine if, following manual therapy: (1) changes occur in active range of movement (AROM) and stiffness of posteroanterior (PA) movements, (2) such changes are dependent on the location treated, and (3) there is a relation between changes in PA stiffness and AROM.

SUMMARY OF BACKGROUND DATA

PA movements are frequently used to assess patients with neck pain but little is known about how these movements are related to patient symptoms.

METHODS

One location deemed symptomatic and hypomobile and 1 asymptomatic location were selected in 20 patients with neck pain for more than 2 weeks. PA stiffness at each location and AROM were measured before and after each of 4 manual therapy interventions: PA movements to each location, a general treatment, and a control intervention.

RESULTS

The general intervention had a greater increase in each axis of AROM than the other interventions (F = 2.814 to 7.929, DF = 3) but there were no differences in PA stiffness across interventions (F = 0.945, DF = 3). Differences in PA stiffness was divided into regions by applied force. After treatment to the symptomatic location, regions of stiffness at forces above 8 N demonstrated significant correlations with total AROM (R = -0.466 to -0.628).

CONCLUSION

After manual therapy, increased AROM is related to decreased PA stiffness in patients with neck pain, but only for the treated location and only when that location had been identified previously as symptomatic and hypomobile.

Whole-spine dynamic magnetic resonance study of contortionists: anatomy and pathology

OBJECT

Whole-spine magnetic resonance (MR) images were obtained using a cylindrical 3-T MR imaging system in 5 contortionists to assess the pathological changes possibly associated with the practice of contortion. Whole-spine dynamic MR images were obtained using a 1-T open MR imaging system in 2 of these contortionists with the purpose of defining the range of motion (ROM) achieved during extreme contortion. The range of spinal motion in this unique population was then quantified.

METHODS

The study included 5 female contortionists 20-49 years of age. Imaging was performed using open 1-T and cylindrical 3-T high-field MR imaging systems. Data were viewed and analyzed with DICOM-compliant tools. Real-time, dynamic, and standard MR imaging allowed for quantification of the contortionists' ROM.

RESULTS

There was a difference of 238 degrees between full spinal extension and full flexion. Three of the 5 contortionists had 4 anterosuperior limbus vertebrae at T-11 and the upper lumbar levels.

CONCLUSIONS

Whole-spine dynamic MR imaging is a valuable tool for the evaluation of the extreme ROM in contortionists, allowing for the quantification of extreme mobility. The limbus fractures present in 3 of the 5 contortionists is postulated to be due to avulsion on hyperextension. Future research may open the use of whole-spine dynamic MR imaging into such areas as pain management and traumatic spinal injuries.

Measurement of vertebral kinematics using noninvasive image matching method-validation and application

STUDY DESIGN

In vitro and in vivo laboratory study.

OBJECTIVE

To validate a dual fluoroscopic image matching technique for measurement of in vivo spine kinematics.

SUMMARY OF BACKGROUND DATA

Accurate knowledge of the spinal structural functions is critical to understand the biomechanical factors that affect spinal pathology. Many studies have investigated vertebral motion both in vitro and in vivo. However, determination of in vivo motion of the vertebrae under physiologic loading conditions remains a challenge in biomedical engineering because of the limitations of current technology and the complicated anatomy of the spine.

METHODS

In in vitro validation, an ovine spine was moved to a known distance in a known speed by an MTS machine. The dual fluoroscopic system was used to capture the spine motion and reproduce the moving distance and speed. In in vivo validation, a living subject moved the spine in various positions under weightbearing. The fluoroscopes were used to reproduce the in vivo spine positions 5 times. The standard deviations in translation and orientation of the 5 measurements were used to evaluate the repeatability of technique.

RESULTS

The translation positions of the ovine spine could be determined with a mean accuracy less than 0.40 mm for the image matching technique using magnetic resonance image-based vertebral models. The spine speed could be reproduced within an accuracy of 0.2 mm/s. The repeatability of the method in reproducing in vivo human spine 6DOF kinematics was less than 0.3 mm in translation and less than 0.7 degrees in orientation.

CONCLUSION

The image matching technique was accurate and repeatable for noninvasive measurement of spine vertebral motion. The technique could be a useful tool for determination of vertebral positions and orientations before and after surgical treatment of spinal pathology to evaluate and improve the efficacy of the various surgical methods in restoring normal spine function.

Manual physical assessment of spinal segmental motion: intent and validity

Validity of a clinical test can be defined as the extent to which the test actually assesses what it is intended to assess. In order to investigate the validity of manual physical assessment of the spine, it is therefore essential to establish what physical therapists intend to assess when they are applying these tests. The aims of this study were to (1) establish what manual physical therapists are intending to assess while applying passive intervertebral motion tests; and (2) examine the face validity and content validity for manual physical assessment of the spine. We surveyed 1502 members of the national manual physical therapist organisations of New Zealand and the United States of America using a web-based survey instrument. Sixty-six percent of 466 respondents believed passive accessory intervertebral motion (PAIVM) tests were valid for assessing quantity of segmental motion, and 76% believed passive physiologic intervertebral motion (PPIVM) tests were valid for assessing quantity of segmental motion. Ninety-eight percent of manual physical therapists base treatment decisions at least in part on the results of segmental motion tests. Quality of resistance to passive segmental motion was considered of greater importance than quantity of kinematic motion during PAIVM tests, while the quality of complex kinematic motion was considered of greater importance than quantity of displacement kinematics during PPIVM tests. Manual physical therapists accept the face validity of manual physical assessment of spinal segmental motion to a great extent, however a minority voice scepticism. Content validity is dominated by concepts of segmental kinematics and the force-displacement relationship. Intent of assessment does, however, vary widely between therapists. These data will inform the design of concurrent validity studies. Further work is recommended to increase consistency of intent, methodology and terminology in manual physical assessment of the spine.