Biomechanical analysis of two-step traction therapy in the lumbar spine

Multi-joint protective effects of lumbar brace on lumbar, hip, knee, and ankle in parachute landing with backpack load

There were high injury risks on lumbar and lower limb joints in parachuting landing, and the lumbar brace could protect lumbar. Besides, a backpack load was necessary in parachute landing and increased the injury risk. This study aimed to evaluate multi-joints protective effects of the lumbar brace on lumbar and lower limb joints in parachuting landing with the backpack load. Seven participants landed from a 120 cm height platform without and with a lumbar brace and without and with a 5-kg backpack load, respectively. Infrared makers were pasted on trunk, pelvis, and lower limb in order to build a multi-rigid-body model for calculating kinematic and kinetic parameters. The joint angular displacements of lumbar and ankle and the peak vertical ground reaction force were significantly decreased from 29.2 ± 9.2°, 45.2 ± 7.8°, and 14.7 ± 2.0 bodyweight to 21.6 ± 4.9° (p < 0.05), 39.0 ± 10.1° (p < 0.05) and 10.7 ± 1.3 bodyweight (p < 0.05) respectively by the lumbar brace with no backpack load, and the joint angular displacement of hip was significantly increased from 52.6 ± 7.2° to 68.3 ± 12.5° (p < 0.05). The joint angular displacement of lumbar and ankle were significantly decreased from 29.0 ± 5.0° and 53.8 ± 5.1° to 25.1 ± 5.2° (p < 0.05) and 48.5 ± 2.5° (p < 0.05) respectively by the lumbar brace with the backpack load, and the joint angular displacement of hip and knee were significantly increased from 60.1 ± 8.2° and 110.1 ± 9.3° to 69.7 ± 13.2° (p < 0.05) and 116.8 ± 5.8° (p < 0.05), respectively. The lumbar brace could provide the multi-joint protective effect by decreasing injuries of lumbar and ankle in landing both without and with the backpack load.

Computational modeling of posteroanterior lumbar traction by an automated massage bed: predicting intervertebral disc stresses and deformation

Spinal traction is a physical intervention that provides constant or intermittent stretching axial force to the lumbar vertebrae to gradually distract spinal tissues into better alignment, reduce intervertebral disc (IVD) pressure, and manage lower back pain (LBP). However, such axial traction may change the normal lordotic curvature, and result in unwanted side effects and/or inefficient reduction of the IVD pressure. An alternative to axial traction has been recently tested, consisting of posteroanterior (PA) traction in supine posture, which was recently shown effective to increase the intervertebral space and lordotic angle using MRI. PA traction aims to maintain the lumbar lordosis curvature throughout the spinal traction therapy while reducing the intradiscal pressure. In this study, we developed finite element simulations of mechanical therapy produced by a commercial thermo-mechanical massage bed capable of spinal PA traction. The stress relief produced on the lumbar discs by the posteroanterior traction system was investigated on human subject models with different BMI (normal, overweight, moderate obese and extreme obese BMI cases). We predict typical traction levels lead to significant distraction stresses in the lumbar discs, thus producing a stress relief by reducing the compression stresses normally experienced by these tissues. Also, the stress relief experienced by the lumbar discs was effective in all BMI models, and it was found maximal in the normal BMI model. These results are consistent with prior observations of therapeutic benefits derived from spinal AP traction.

Study on the process of intervertebral disc disease by the theory of continuum damage mechanics

BACKGROUND

Recently, more and more people suffer from low back pain triggered by lumbar degenerative disc disease. The mechanical factor is one of the most significant causes of disc degeneration. This study aims to explore the biomechanical responses of the intervertebral disc, and investigate the process of disc injury by the theory of continuum damage mechanics.

METHODS

A finite element model of the L4-L5 lumbar spine was developed and validated. The model not only considered changes in permeability coefficient with strain, but also included physiological factors such as osmotic pressure. Three loading conditions were simulated: (A) static loads, (B) vibration loads, (C) injury process.

FINDINGS

The simulation results revealed that the facet joints shared massive stresses of the intervertebral discs, and prevented excessive lumbar spine movement. However, their asymmetrical position may have led to degeneration. The von Mises stress and pore pressure of annulus fibrosus showed significantly different trends under static loads and vibration loads. The von Mises stress of nucleus pulposus was not sensitive to vibration loads, but its pore pressure was conspicuously influenced by vibration loads. The injury first appeared at the posterior centre, and then, it gradually expanded along the edge of the intervertebral disc. With an increase in the loading steps, the damage rate of the intervertebral disc increased logarithmically.

INTERPRETATION

The variation in the biomechanical performance of the intervertebral disc could be attributed to the periodic movement of internal fluids. This study might be helpful for understanding the mechanism of intervertebral disc degeneration.

Immediate effect of mechanical lumbar traction in patients with chronic low back pain: A crossover, repeated measures, randomized controlled trial

BACKGROUND

Lumbar traction is a treatment method traditionally used for chronic low back pain (CLBP) in many countries. However, its clinical effectiveness has not been proven in medical practice. The purpose is to conduct a multi-center, crossover, randomized controlled trial (RCT) to prove the efficacy and safety of traction on CLBP patients, using equipment capable of precise traction force control and of reproducibility of the condition based on the previous biomechanical and pre-clinical studies.

METHODS

Ninety-five patients with non-specific CLBP from 28 clinics and hospitals were randomly assigned to either the intermittent traction with vibration (ITV) first group (A: sequence ITV to ITO) or the intermittent traction only (ITO) first group (B: sequence ITO to ITV); the former was treated with repeated traction and vibration force added to preload. All patients were followed up weekly for 2 periods after study-initiation. The primary outcome measures were disability level including pain and quality of life (based on Japan Low back pain Evaluation Questionnaire; JLEQ), and JLEQ was measured repeatedly. Statistical analysis was performed using linear mixed model.

RESULTS

Comparing to pre-traction data, both traction modes significant improvement except the first intervention of ITO treatment. The differences in JLEQ scores over time showed significant improvements in the treatment to which vibrational force was added in contrast to the conventional traction treatment; Mean difference was significant to compare ITV treatment and ITO treatment (-1.75 (p = 0.001), 95% CI; -2.69 to -0.80). However, neither difference between the two sequences (p = 0.884) nor carryover effect (p = 0.527) was observed.

CONCLUSIONS

Altogether, the results indicate that lumbar traction was able to improve the pain and functional status immediately in patients with CLBP. This study contributes to add some evidence of the efficacy of lumbar traction.

Effects of One-Fifth, One-Third, and One-Half of the Bodyweight Lumbar Traction on the Straight Leg Raise Test and Pain in Prolapsed Intervertebral Disc Patients: A Randomized Controlled Trial

The prolapsed intervertebral disc (PIVD) at the lumbar spine is one of the most common causes of low back pain (LBP) affecting humans worldwide. Lumbar traction is widely used as a part of physiotherapeutic modalities for its treatment; however, reports on its effectiveness and dosage are conflicting. This study is aimed at comparing the acute effects of three traction forces on the straight leg raise (SLR) test and LBP intensity. A total of 45 (age 35.53 yrs., ±3.09) participants with 15 participants in each group were recruited for the study. Participants were divided into groups A, B, and C wherein traction forces equal to one-fifth, one-third, and one-half of their bodyweight were applied, respectively. SLR range of motion (ROM) and pain were examined before and immediately after the application of traction. Significant improvement was observed in SLR ROM in all three groups (p < 0.05). However, for pain, significant improvement (p < 0.05) was observed only in the group with one-half of bodyweight force. There was no significant difference (p > 0.05) between the three groups for both variables. All three forces were equally effective in immediately improving SLR ROM in patients suffering from lumbar PIVD; however, pain improvement was observed with one-half of bodyweight only.

Mechanical Changes of the Lumbar Intervertebral Space and Lordotic Angle Caused by Posterior-to-Anterior Traction Using a Spinal Thermal Massage Device in Healthy People

Background: The axial (horizontal) traction approach has been traditionally used for treatment of low back pain-related spinal disorders such as nuclear protrusion, primary posterolateral root pain, and lower thoracic disc herniation; however, it is known to have some technical limitations due to reductions of the spinal curve. Lumbar lordosis plays a pivotal function in maintaining sagittal balance. Recently, vertical traction and combination traction have been attracting attention due to improving therapeutic outcomes, although evidence of their clinical application is rare; therefore, this study was conducted to investigate the mechanical changes of lumbar intervertebral space, lordotic angle, and the central spinal canal area through vertical traction treatment using a spinal massage device in healthy participants. Methods: In total, 10 healthy subjects with no musculoskeletal disorders and no physical activity restrictions participated. The participants lay on the experimental device (CGM MB-1901) in supine extended posture and vertical traction force was applied in a posterior-to-anterior direction on the L3–4 and L4–5 lumbar sections at level 1 (baseline) and level 9 (traction mode). Magnetic resonance (MR) images were recorded directly under traction mode using the MRI scanner. The height values of the intervertebral space (anterior, center, and posterior parts) and lordosis angle of the L3–4 and L4–5 sections were measured using Image J software and the central spinal canal area (L4–5) was observed through superimposition method using the MR images. All measurement and image analyses were conducted by 2 experienced radiologists under a single-blinded method. Results: The average height values of the intervertebral space under traction mode were significantly increased in both L3–4 and L4–5 sections compared to baseline, particularly in the anterior and central parts but not in the posterior part. Cobb’s angle also showed significant increases in both L3–4 and L4–5 sections compared to baseline (p < 0.001). The central spinal canal area showed a slightly expanded feature in traction mode. Conclusions: In this pilot experiment, posterior-to-anterior vertical traction on L3–4 and L4–5 sections using a spinal massage device caused positive and significant changes based on increases of the intervertebral space height, lumbar lordosis angle, and central spinal canal area compared to the baseline condition. Our results are expected to be useful as underlying data for the clinical application of vertical traction.

Finite element analysis of lumbar spine with different backpack positions in parachuting landing

The purpose of this study was to investigate the lumbar spine stress with different backpack positions in parachuting landing using a finite element model of lumbar vertebra 1-5. The backpack gravity center was set at three positions (posterior-high (case PH), posterior-low (case PL), and anterior-low (case AL)) respectively. In results, the peak Von-Mises stresses of the matrix, nucleus, fibers, endplate and ligament in case AL were 2.765 MPa, 0.534 MPa, 6.561 MPa, 4.045 MPa and 1.790 MPa respectively, lower than those in case PL (6.913 MPa, 1.316 MPa, 20.716 MPa, 10.917 MPa and 5.147 MPa respectively) and case PH (7.328 MPa, 1.394 MPa, 22.147 MPa, 11.617 MPa and 5.464 MPa respectively). In conclusion, setting the gravity center of backpack at anterior-low position would reduce lumbar spine stress and reduce lumbar spine injuries.

The Real Time Geometric Effect of a Lordotic Curve-Controlled Spinal Traction Device: A Randomized Cross Over Study

Background: A standard spinal traction (ST) device was designed to straighten the spine without considering physiological lumbar lordosis. Using lordotic curve-controlled traction (LCCT), which maintains the lordotic curve during traction, the traction force would be applied to the posterior spinal structure effectively. Thus, the purpose of our study was to evaluate real-time biomechanical changes while applying the LCCT and ST. Methods: In this study, 40 subjects with mild non-radicular low back pain (LBP) were included. The participants underwent LCCT and ST in random order. Anterior and posterior intervertebral distance, ratios of anterior/posterior intervertebral distance (A/P ratio), and lordotic angles of intervertebral bodies (L2~L5) were measured by radiography. Results: Mean intervertebral distances were greater during LCCT than those measured prior to applying traction (p < 0.05). Mean A/P ratio was also significantly greater during LCCT than during ST or initially (p < 0.05). In particular, for the L4/5 intervertebral segment, which is responsible for most of the lordotic curve, mean LCCT angle was similar to mean lordotic angle in the standing position (10.9°). Conclusions: Based on measurements of radiologic geometrical changes with real-time clinical setting, the newly developed LCCT appears to be a useful traction device for increasing intervertebral disc spaces by maintaining lordotic curves.

The effect of mechanical traction on low back pain in patients with herniated intervertebral disks: a systemic review and meta-analysis

OBJECTIVE

To evaluate the effectiveness of traction in improving low back pain, functional outcome, and disk morphology in patients with herniated intervertebral disks.

DATA SOURCE

PubMed, Scopus, Embase, and the Cochrane Library were searched from the earliest record to July 2019.

REVIEW METHODS

We included randomized control trials which (1) involved adult patients with low back pain associated with herniated disk confirmed by magnetic resonance imaging or computed tomography, (2) compared lumbar traction to sham or no traction, and (3) provided quantitative measurements of pain and function before and after intervention. Methodological quality was assessed using the physiotherapy evidence database (PEDro) scale and Cochrane risk of bias assessment.

RESULTS

Initial searches for literature yielded 3015 non-duplicated records. After exclusion based on the title, abstract, and full-text review, 7 articles involving 403 participants were included for quantitative analysis. Compared with the control group, the participants in the traction group showed significantly greater improvements in pain and function in the short term, with standard mean differences of 0.44 (95% confidence interval (CI): 0.11-0.77) and 0.42 (95% CI: 0.08-0.76), respectively. The standard mean differences were not significant to support the long-term effects on pain and function, nor the effects on herniated disk size.

CONCLUSION

Compared with sham or no traction, lumbar traction exhibited significantly more pain reduction and functional improvements in the short term, but not in the long term. There is insufficient evidence to support the effect of lumbar traction on herniated disk size reduction.

Mechanical Traction for Lumbar Radicular Pain: Supine or Prone? A Randomized Controlled Trial

OBJECTIVE

The aim of the study was to compare the effects of mechanical lumbar traction either in the supine or in the prone position with conventional physical therapy (PT) in patients with chronic low back pain and lumbosacral nerve root involvement in terms of disability, pain, and mobility.

DESIGN

Participants (N = 125) were randomly assigned to receive 15 sessions of PT with additional mechanical lumbar traction either in the supine position (supine traction group) or in the prone position (prone traction group) or only PT without traction (PT only group). Patients were assessed at baseline and at the end of the PT sessions in terms of disability, pain, and mobility. Disability was assessed using the modified Oswesty Disability Index; pain was assessed using a visual analog scale, and lumbar mobility was assessed using the modified lumbar Schober test.

RESULTS

One hundred eighteen patients completed the trial. All groups improved significantly in the Oswesty Disability Index, visual analog scale, and modified lumbar Schober test (P < 0.05). In the between-group analysis, improvements of Oswesty Disability Index and visual analog scale were found significantly better in the prone traction group compared with the PT only group (adjusted P = 0.031 and 0.006, respectively).

CONCLUSIONS

Addition of traction in the prone position to other modalities resulted in larger immediate improvements in terms of pain and disability, and the results suggest that when using traction, prone traction might be first choice. Further research is needed to confirm the benefits of lumbar traction in the prone position.

Lumbar mechanical traction: a biomechanical assessment of change at the lumbar spine

BACKGROUND

Lumbar traction is a traditional treatment modality for chronic low back pain (CLBP) in many countries. However, its effectiveness has not been demonstrated in clinical practice because of the following: (1) the lack of in vivo biomechanical confirmation of the mechanism of lumbar traction that occurs at the lumbar spine; (2) the lack of a precise delivery system for traction force and, subsequently, the lack of reproducibility; and (3) few randomized controlled trials proving its effectiveness and utility.

METHODS

This study was planned as a preparatory experiment for a randomized clinical trial, and it aimed (1) to examine the biomechanical change at the lumbar area under lumbar traction and confirm its reproducibility and accuracy as a mechanical intervention, and (2) to reconfirm our clinical impression of the immediate effect of lumbar traction. One hundred thirty-three patients with non-specific CLBP were recruited from 28 orthopaedic clinics to undergo a biomechanical experiment and to assess and determine traction conditions for the next clinical trial. We used two types of traction devices, which are commercially available, and incorporated other measuring tools, such as an infrared range-finder and large extension strain gauge. The finite element method was used to analyze the real data of pelvic girdle movement at the lumbar spine level. Self-report assessments with representative two conditions were analyzed according to the qualitative coding method.

RESULTS

Thirty-eight participants provided available biomechanical data. We could not measure directly what happened in the body, but we confirmed that the distraction force lineally correlated with the movement of traction unit at the pelvic girdle. After applying vibration force to preloading, the strain gauge showed proportional vibration of the shifting distance without a phase lag qualitatively. FEM simulation provided at least 3.0-mm shifting distance at the lumbar spine under 100 mm of body traction. Ninety-five participants provided a treatment diary and were classified as no pain, improved, unchanged, and worsened. Approximately 83.2% of participants reported a positive response.

CONCLUSION

Lumbar traction can provide a distractive force at the lumbar spine, and patients who experience the application of such force show an immediate response after traction.

TRIAL REGISTRATION

University Hospital Medical Information Network - Clinical Trial Registration: UMIN-CTR000024329 (October 13, 2016).

Comparisons of the Effectiveness and Safety of Tuina, Acupuncture, Traction, and Chinese Herbs for Lumbar Disc Herniation: A Systematic Review and Network Meta-Analysis

Background

Tuina, acupuncture, traction, and Chinese herbs play an important role in the treatment of lumbar disc herniation. However, the comparative effectiveness and safety of the four commonly utilized treatment modalities are still unclear.

Objective

To compare the effectiveness and safety of the four interventions for lumbar disc herniation.

Methods

Randomized controlled trials comparing any two of the four interventions in the treatment of lumbar disc herniation were identified using the following databases: PubMed, the Cochrane Library, Embase, Web of Science, the China National Knowledge Infrastructure, Chinese Science and Technology Periodical Database, and Wanfang data, and network meta-analysis was performed using STATA 14.0.

Results

One hundred and twenty-one studies involving a total of 13075 patients were included. In all the outcome measurements, traction demonstrated a worst effectiveness, and Tuina and acupuncture demonstrated a best effectiveness, but no significant differences were found between Tuina and acupuncture. Compared with Tuina or acupuncture, Chinese herbs showed a similar effectiveness in Visual Analogue Score and Japanese Orthopedic Association Scores, but an inferior effectiveness in invalid rate and cure rate.

Conclusions

In the treatment of lumbar disc herniation, Tuina and acupuncture were superior to traction or Chinese herbs, and the effectiveness of traction was the worst. However, considering the limitations of this review, more high-quality trials, especially those comparing Chinese herbs with the other three interventions, should be carried out in the future to further confirm the current findings.

Effects of Different Angles of the Traction Table on Lumbar Spine Ligaments: A Finite Element Study

Background

The traction bed is a noninvasive device for treating lower back pain caused by herniated intervertebral discs. In this study, we investigated the impact of the traction bed on the lower back as a means of increasing the disc height and creating a gap between facet joints.

Methods

Computed tomography (CT) images were obtained from a female volunteer and a three-dimensional (3D) model was created using software package MIMICs 17.0. Afterwards, the 3D model was analyzed in an analytical software (Abaqus 6.14). The study was conducted under the following traction loads: 25%, 45%, 55%, and 85% of the whole body weight in different angles.

Results

Results indicated that the loading angle in the L3–4 area had 36.8%, 57.4%, 55.32%, 49.8%, and 52.15% effect on the anterior longitudinal ligament, posterior longitudinal ligament, intertransverse ligament, interspinous ligament, and supraspinous ligament, respectively. The respective values for the L4–5 area were 32.3%, 10.6%, 53.4%, 56.58%, and 57.35%. Also, the body weight had 63.2%, 42.6%, 44.68%, 50.2%, and 47.85% effect on the anterior longitudinal ligament, posterior longitudinal ligament, intertransverse ligament, interspinous ligament, and supraspinous ligament, respectively. The respective values for the L4–5 area were 67.7%, 89.4%, 46.6%, 43.42% and 42.65%. The authenticity of results was checked by comparing with the experimental data.

Conclusions

The results show that traction beds are highly effective for disc movement and lower back pain relief. Also, an optimal angle for traction can be obtained in a 3D model analysis using CT or magnetic resonance imaging images. The optimal angle would be different for different patients and thus should be determined based on the decreased height of the intervertebral disc, weight and height of patients.

Mechanical effects of traction on lumbar intervertebral discs: A magnetic resonance imaging study

BACKGROUND

Although traction has long been used for treating patients with low back pain (LBP), its effects are still inconclusive mainly because of limited high-quality evidence.

OBJECTIVE

To provide evidence of the mechanism of traction on lumbar intervertebral discs.

DESIGN

A quantitative approach with a repeated measurement protocol.

METHOD

Nine participants (mean age = 22.1 ± 0.8 years) without any LBP history were recruited. Magnetic Resonance Images of the lumbar spine of each participant were recorded before and after 30 min of horizontal lying and directly after 30 min of horizontal traction of 42% body weight. The average, anterior, central, and posterior disc height and tilt angle of each lumbar disc and lumbar lordosis were measured.

RESULTS

A significant increase in the average disc height for all lumbar discs, a significant reduction of lumbar lordosis and changes in tilt angle were observed after the application of 30 min of resting followed by 30 min of traction. A significant increase in the average disc height was observed only in lower lumbar discs after 30 min of traction. The increase in the posterior disc height was more apparent than that in the anterior disc height.

CONCLUSIONS

Horizontal traction was evidently effective in increasing the disc height of lower lumbar levels, particularly in the posterior regions of the discs. Further evidence of the effects of traction of different modes, magnitudes, and durations on the change in disc height is required for proper control of traction applied to specific disc levels.

Effects of segmental traction therapy on lumbar disc herniation in patients with acute low back pain measured by magnetic resonance imaging: A single arm clinical trial

BACKGROUND

Low Back Pain (LBP) is considered as one of the most frequent disorders, which about 80% of adults experience in their lives. Lumbar disc herniation (LDH) is a cause for acute LBP. Among conservative treatments, traction is frequently used by clinicians to manage LBP resulting from LDH. However, there is still a lack of consensus about its efficacy.

OBJECTIVE

The purpose of this study was to evaluate the effects of segmental traction therapy on lumbar discs herniation, pain, lumbar range of motion (ROM), and back extensor muscles endurance in patients with acute LBP induced by LDH.

METHODS

Fifteen patients with acute LBP diagnosed by LDH participated in the present study. Participants undertook 15 sessions of segmental traction therapy along with conventional physiotherapy, 5 times a week for 3 weeks. Lumbar herniated mass size was measured before and after the treatment protocol using magnetic resonance imaging. Furthermore, pain, lumbar ROM and back muscle endurance were evaluated before and after the procedure using clinical outcome measures.

RESULTS

Following the treatment protocol, herniated mass size and patients' pain were reduced significantly. In addition, lumbar flexion ROM showed a significant improvement. However, no significant change was observed for back extensor muscle endurance after the treatment procedure.

CONCLUSION

The result of the present study showed segmental traction therapy might play an important role in the treatment of acute LBP stimulated by LDH.

Is Preventative Long-Segment Surgery for Multi-Level Spondylolysis Necessary? A Finite Element Analysis Study

Objective

For multi-level spondylolysis patients, surgeons commonly choose to fix all the segments with pars interarticularis defect even those without slippage and not responsible for clinical symptoms. In this study, we tried to study the necessity of the preventative long-segment surgery for the defected segment without slippage in treatment of multi-level spondylolysis patients from a biomechanical perspective.

Method

We established a bi-level spondylolysis model with pars defects at L4 and L5 segments, and simulated posterior lumbar interbody fusion (PLIF) and pedicle screw fixation at L5-S1 level. Then we compared the biomechanical changes at L4 segment before and after surgery in neutral, flexion, extension, lateral bending and axial rotation position.

Results

The stress on L4 pars interarticularis was very similar before and after surgery, and reached the highest in axial rotation. The L3-L4 intradiscal pressure was almost the same, while L4-L5 intradiscal pressure changed a little in lateral bending (increase from 1.993 to 2.160 MPa) and axial rotation (decrease from 1.639 to 1.307 MPa) after surgery. The PLIF surgery caused a little increase of range of motion at adjacent L4-L5 and L3-L4 levels, but the change is very tiny (1 degree).

Conclusion

The PLIF surgery will not cause significant biomechanical change at adjacent segment with pars defect in multi-level spondylolysis. On the contrary, excessive long-segment surgery will damage surrounding soft tissues which are important for maintaining the stability of spine. So a preventative long-segment surgery is not necessary for multi-level spondylolysis as long as there are no soft tissue degeneration signs at adjacent level.