Three-Dimensional Spinal Position With and Without Manual Distraction Load Increases Spinal Height

ObjectiveThe purpose of this study was to investigate if spinal height increases using 3-dimensional (3-D) spinal position with and without manual distraction load and to assess the correlation between spine height changes and degrees of trunk rotation.MethodsFifty-six participants were randomly placed in one of two groups: (1) 3-D spinal position with manual distraction load, and (2) without manual distraction load. Spinal height was measured before and after the interventions using a stadiometer. For the statistical analysis, we used a 2 (Loading status: pre- versus post-intervention height) X 2 (3-D spinal position: with versus without manual distraction load) repeated measures Analysis of Variance (ANOVA) was used to identify significant interaction and main effects. Paired t-tests were used to calculate differences in spinal height changes between the two interventions. Pearson correlation coefficient was used to measure correlations between changes in spinal heights and degrees of trunk rotation.ResultsMean spinal height increase with 3-D spinal position with and without manual distraction load was 6.30 mm (±6.22) and 5.69 mm (±4.13), respectively. No significant interaction effect was present between loading status and 3-D spinal position but a significant main effect in loading status was. Paired t-tests revealed significant differences in spinal heights between pre-and post-3-D spinal position with and without manual distraction load. No significant correlation was measured between trunk rotation and spinal height changes.Conclusion3-D spinal position with or without distraction load increased spinal height. This suggests that 3-D spinal positioning without manual distraction could be used in home settings to help maintain intervertebral disc (IVD) health.     

Spinal Height Change in Response to Sustained and Repetitive Prone Lumbar Extension After a Period of Spinal Unloading

Objective

The purpose of this study was to investigate if differences in spinal height changes in healthy individuals were observed after a period of spinal unloading using repetitive as compared with sustained lumbar extension exercises.

Methods

This study used a pretest, posttest, crossover design. Asymptomatic participants were recruited using convenience sampling. Thirty-two participants (15 male; 17 female) without back pain were included in the data analysis (mean, 24.4 years; range, 20-41 years). Participants performed sustained or repetitive prone lumbar extension exercises after 1 hour of sustained spinal unloading. Spinal height was measured using a stadiometer before and after the repetitive and sustained prone lumbar extension exercises.

Results

Paired t tests revealed no significant difference in spine height after repetitive (P = .774) or sustained (P = .545) prone lumbar extension after a period of spinal unloading. No significant difference between spinal height changes occurred between sustained (mean [SD], − 0.28 [2.59] mm) and repetitive (mean [SD], − 0.12 [2.42] mm) lumbar extension (P = .756).

Conclusion

In this group of asymptomatic individuals, sustained and repetitive lumbar extension exercises did not appear to affect spinal height after a period of spinal unloading.     

Predictors of walking performance and walking capacity in people with lumbar spinal stenosis, low back pain, and asymptomatic controls

Tomkins-Lane CC, Holz SC, Yamakawa KS, Phalke VV, Quint DJ, Miner J, Haig AJ. Predictors of walking performance and walking capacity in people with lumbar spinal stenosis, low back pain, and asymptomatic controls.ObjectiveTo examine predictors of community walking performance and walking capacity in people with lumbar spinal stenosis (LSS), compared with people with low back pain and asymptomatic control subjects.DesignRetrospective analysis.SettingUniversity spine program.ParticipantsParticipants (N=126; 50 LSS, 44 low back pain, 32 asymptomatic control subjects) aged 55 to 80 years were studied.InterventionsNot applicable.Main Outcome MeasuresSeven-day community walking distance measured by pedometer (walking performance) and a 15-minute walking test (walking capacity). All participants had lumbosacral magnetic resonance imaging, electrodiagnostic testing, and a history and physical examination, including a history of pain and neurologic symptoms, a straight leg raise test, and tests for directional symptoms, reflexes, strength, and nerve tension signs. The study questionnaire included demographic information, a history of back/leg pain, and questions about walking, exercise frequency, and pain level, as well as the standardized Quebec Back Pain Disability Scale.ResultsBody mass index (BMI), pain, age, and female sex predicted walking performance (r²=.41) and walking capacity (r²=.41). The diagnosis of LSS itself had no clear relationship with either walking variable. Compared with the asymptomatic group, LSS participants had significantly lower values for all walking parameters, with the exception of stride length, while there was no significant difference between the LSS and low back pain groups.ConclusionsBMI, pain, female sex, and age predict walking performance and capacity in people with LSS, those with low back pain, and asymptomatic control subjects. While pain was the strongest predictor of walking capacity, BMI was the strongest predictor of walking performance. Average pain, rather than leg pain, was predictive of walking performance and capacity. Obesity and pain are modifiable predictors of walking deficits that could be targets for future intervention studies aimed at increasing walking performance and capacity in both the low back pain and LSS populations.     

Passive stiffness characteristics and neutral zone quality of the scoliotic lumbar torso in the principle anatomical planes of motion

BackgroundThe 1–10% prevalence rate of adult scoliosis frequently requires expensive therapy and surgical treatments and demands further research into the disease, especially with an aging population. Most studies examining the mechanics of scoliosis have focused on in vitro testing or computer simulations. This study quantitatively defined the passive stiffness properties of the in vivo scoliotic spine in three principle anatomical motions and identified differences relative to healthy controls.MethodsAdult scoliosis (n = 14) and control (n = 17) participants with no history of spondylolisthesis, spinal fracture, or spinal surgery participated in three different tests (torso lateral side bending, torso axial rotation, and torso flexion/extension) that isolated mobility to the in vivo lumbar spine. The spinal stiffnesses and spinal neutral zone width were calculated. These parameters were statistically compared between factor of population and within factor of direction.FindingsTorque-rotational displacement data were fit using a double sigmoid function, resulting an in excellent overall fit (Avg. R² = 0.95). There was a significant interaction effect between populations when comparing axial twist neutral zone width vs. lateral bend neutral zone width and axial twist stiffness vs. lateral bend stiffness. The axial twist neutral zone width magnitude was significantly larger in scoliosis patients.InterpretationThe present study is the first investigation to quantify the whole trunk neutral zone of the scoliotic lumbar spine. Future research is needed to determine if lumbar spine mechanical characteristics can help explain progression of scoliosis and complement scoliosis classification systems.     

Intervertebral neural foramina deformation due to two types of repetitive combined loading

Background

Tissue compression and noxious stimuli are known to elicit pain from neural tissues in the spine. Compression of nerve roots due to decreases in the intervertebral foramina may be caused by posture, sustained loading and disc height loss, herniation, or altered mechanics. It has been established that non-neutral postures combined with repeated loading can cause disc herniations, however information regarding the effect of repetitive axial twist loading is limited. The objectives of this study were twofold; to measure the occlusion of the foramina due to two types of repetitive loading and to investigate whether repetitive combined axial twist loading can contribute to disc injury.

Methods

Sixteen porcine cervical spine segments (C5/6) were subjected to 1500 N of compression combined with either repetitive flexion–extension motions or 16.4° (Standard Deviation 2.1) of static flexion with repetitive axial twist motions. The foramina pressure was measured bilaterally using plastic tubing and a custom pressure monitoring system. Specimens were loaded until 10,000 cycles were reached or disc herniation occurred.

Findings

Significantly larger pressure (pre–post difference) developed in the intervertebral foramina of specimens that were repetitively flexed–extended (P = 0.028) compared to those that were repetitively twisted. All of the flexed–extended specimens herniated, whereas in the twisted specimens five (62.5%) had incomplete herniations, one (12.5%) sustained a facet fracture, and two (25%) had no damage. There was no difference between the loading groups for vertical height loss (P = 0.994).

Interpretation

Repetitive loading of flexion–extension motions are a viable pain generating pathway in absence of distinguishing height loss. This information may be useful to consider for the diagnosis and treatment of nerve root compression.     

Understanding how axial loads on the spine influence segmental biomechanics for idiopathic scoliosis patients: A magnetic resonance imaging study

BackgroundSegmental biomechanics of the scoliotic spine are important since the overall spinal deformity is comprised of the cumulative coronal and axial rotations of individual joints. This study investigates the coronal plane segmental biomechanics for adolescent idiopathic scoliosis patients in response to physiologically relevant axial compression.MethodsIndividual spinal joint compliance in the coronal plane was measured for a series of 15 idiopathic scoliosis patients using axially loaded magnetic resonance imaging. Each patient was first imaged in the supine position with no axial load, and then again following application of an axial compressive load. Coronal plane disc wedge angles in the unloaded and loaded configurations were measured. Joint moments exerted by the axial compressive load were used to derive estimates of individual joint compliance.FindingsThe mean standing major Cobb angle for this patient series was 46°. Mean intra-observer measurement error for endplate inclination was 1.6°. Following loading, initially highly wedged discs demonstrated a smaller change in wedge angle, than less wedged discs for certain spinal levels (+ 2,+1,− 2 relative to the apex, (p < 0.05)). Highly wedged discs were observed near the apex of the curve, which corresponded to lower joint compliance in the apical region.InterpretationWhile individual patients exhibit substantial variability in disc wedge angles and joint compliance, overall there is a pattern of increased disc wedging near the curve apex, and reduced joint compliance in this region. Approaches such as this can provide valuable biomechanical data on in vivo spinal biomechanics of the scoliotic spine, for analysis of deformity progression and surgical planning.     

Can 5 minutes of repetitive prone press-ups and sustained prone press-ups following a period of spinal loading reverse spinal shrinkage?

Objective: The objective of this study is to investigate if sustained and repetitive prone press-ups could reverse decreased spinal height following spinal loading and if there was a correlation between the degree of end range of motion spinal extension and spinal height gains. Design: Pretest–posttest crossover design is used in this study. Setting: Study was carried out in research laboratory. Subjects: Forty-one healthy men and women were included in this study. Intervention: Participants were seated in the stadiometer for 5 min with a 4.5-kg weight placed on each shoulder; the load was removed for 5 min and spinal height was measured using a stadiometer before and after 5 min of repetitive or sustained prone press-ups. Main Measures: Two-by-two repeated-measures ANOVA to identify significant interactions and main effects is used in this study. Significance of α = 0.05. A Pearson correlation coefficient was used to assess the correlation between spinal height changes and spinal extension ROM. Results: Participants 24.1 ± 2.03 years grew using both repetitive (4.85 ± 3.01 mm) and sustained press ups (4.46 ± 2.57 mm). There was no significant interaction between the repetitive versus sustained press-ups and the time before and after each prone press-ups strategy and no main effect for strategy (sustained vs. repetitive press-ups). There was a significant main effect for time (before vs. after press-ups) (F_(1,30) = 140.771; p < 0.0001; partial η² = 0.82). No correlation was found between the degree of end ROM spinal extension and spinal height changes following press-ups strategies. Conclusion: Following periods of spinal loading, both repetitive and sustained press-ups increased spinal height. Such strategies could be used to help recover spinal height and limit the effects of decreased spinal height as a result of activities of daily living.     

Force transmission between thoracic and cervical segments of the spine during prone-lying high-velocity low-amplitude spinal manipulation: A proof of principle for the concept of regional interdependence

BackgroundRegional interdependence is conceptually based on observations that applying manual therapy to a remote anatomical region has an effect in the area of the patient's primary complaint. The current model for regional interdependence depends on force transmissibility within the body. This investigation sought to determine transmissibility between forces applied to the thoracic spine during prone-lying high-velocity low-amplitude spinal manipulative therapy and the cervical spine.MethodsA chiropractic treatment table was modified to allow (or disallow) translation of the headrest in the caudal-cephalad direction when unlocked (or locked). Prone-lying high-velocity low-amplitude spinal manipulative therapy was applied to the thoracic region of 9 healthy participants with the headrest in both configurations. Head and thorax kinematics and kinetics were measured at interfaces between participant and the external environment, which included the clinician's hands. Compressive forces at the cervicothoracic junction and angular kinematics of the cervical spine were derived. Ratios between the clinician-applied forces (input) and the cervical compressive force (output) were also determined.FindingsThe cervical spine extended during all high-velocity low-amplitude spinal manipulative therapy trials. Force input-to-output ratios exceeded 1 for high-velocity low-amplitude spinal manipulative therapy trials performed with the headrest in the locked configuration, which was greater than ratios for the unlocked configuration.InterpretationForces imparted to thoracic spine during high-velocity low-amplitude spinal manipulative therapy were transmitted to the cervical spine, which provided a precursor for the regional interdependence model for manual therapy. Friction between the participant's face and the treatment table's head rest likely amplified cervical compressive forces.     

Immediate Effects of Manual Traction on Radiographically Determined Joint Space Width in the Hip Joint

Objective

The purpose of this study was to investigate the immediate effects of manual traction of the hip joint on joint space width (JSW) on asymptomatic subjects.

Methods

Asymptomatic, healthy male volunteers (n = 15), aged 25 to 34 years were included in this study. Three radiographs were obtained with the subjects in the supine position, before and after loading with 10% of his body weight, and after manual traction on only the right hip joint. Joint space width was measured by a radiologist at the point described by Jacobson and Sonne-Holm.

Results

There were significant changes in JSW on the right hip joint and left hip joint between the baseline (before loading) and immediately after loading. We also observed a significantly increased JSW on only the right hip joint between periods that followed loading and manual traction on the right hip joint. There was no significant change in JSW on the left hip joint between periods that followed loading and manual traction on the right hip joint.

Conclusions

The results of this study suggest that a significant increase in JSW in young, healthy male patients can occur immediately after manual traction of the hip joint.     

Prediction of the influence of vertical whole-body vibration on biomechanics of spinal segments after lumbar interbody fusion surgery

BackgroundPrevious studies have shown that for healthy spine, cyclic loading encountered due to whole-body vibration exposure generated higher responses in spinal tissues than static loading. However, how whole-body vibration affects spine biomechanics after interbody fusion surgery is poorly understood. This study aimed at comparing the effects of vibration loading on spinal segments between postsurgical and healthy lumbar spines.MethodsA validated finite element model of healthy human lumbosacral spine was modified to simulate interbody fusion at L4–L5 level considering the statuses immediately after surgery (before bony fusion) and after bony fusion. Biomechanical responses at its adjacent levels for the healthy and fusion models to a sinusoidal axial vibration load of ±40 N and the corresponding static axal loads (−40 N and 40 N) were computed using transient dynamic and static analyses, respectively.FindingsFor both healthy and fusion models, vibration amplitudes of the predicted responses were significantly higher than the corresponding changing amplitudes under static loads. Specifically, the increasing effect of vibration load in disc bulge, disc stress and intradiscal pressure at L3–L4 level reached 255.9%, 215.0% and 224.4% for the healthy model, 157.4%, 177.8% and 171.8% for the fusion model (before bony fusion), 141.9%, 152.6% and 160.1% for the fusion model (after bony fusion).InterpretationAlthough whole-body vibration is still more dangerous for the lumbar spine after interbody fusion surgery than static loading, the sensitivity of adjacent segment in postsurgical spine to vibration loading is decreased compared with healthy spine, especially when reaching to bony fusion.     

Effects of Walking With a Shopping Trolley on Spinal Posture and Loading in Subjects With Neurogenic Claudication

Comer CM, White D, Conaghan PG, Bird HA, Redmond AC. Effects of walking with a shopping trolley on spinal posture and loading in subjects with neurogenic claudication.

Objectives

To explore possible mechanisms underpinning symptom relief and improved walking tolerance in patients with neurogenic claudication (NC) when pushing a shopping trolley by evaluating the effects of a shopping trolley on spinal posture and loading patterns.

Design

An exploratory study of kinematic and kinetic changes in walking with and without pushing a shopping trolley in persons with NC symptoms and a comparison with asymptomatic control subjects.

Setting

A primary care-based musculoskeletal service.

Participants

Participants (n=8) with NC symptoms who have anecdotally reported symptomatic improvement when walking with a shopping trolley and a control group of asymptomatic persons (n=8).

Interventions

Shopping trolley.

Main Outcome Measures

Changes in lumbar spinal sagittal posture and ground reaction force.

Results

Subjects with NC and asymptomatic controls walked with significantly more flexed spinal posture (increase in flexion, 3.40°; z=3.516; P<.001) and reduced mean ground reaction forces (−6.9% of body weight; z=−3.46; P=.001) when walking with a shopping trolley. However, at the midstance point of the gait cycle, controls showed minimal reliance on the trolley, whereas, people with NC showed continued offloading.

Conclusions

Both posture and loading are affected by pushing a shopping trolley; however, patients with NC were found to offload the spine throughout the stance phase of gait, whereas asymptomatic controls did not.     

Impact of multilevel facetectomy on segmental spinal flexibility in patients with thoracic adolescent idiopathic scoliosis

BackgroundThe aim of this study was to intraoperatively assess the effects of multilevel facetectomy on segmental spinal flexibility in patients with thoracic adolescent idiopathic scoliosis.MethodsTwenty patients who underwent posterior thoracic adolescent idiopathic scoliosis curve correction were evaluated. Compressive or distractive loaded force of 50N was applied on the handle of a compressor or distractor connected to the necks of pedicle screws inserted at T7 to T11. Segmental spinal flexibility rates were calculated based on the distance between screw heads under the loaded and unloaded conditions. In addition, the flexibility rates were obtained before and after multilevel facetectomy.FindingsAbsolute flexibility rates of all segments significantly increased after multilevel facetectomy under both compressive and distractive forces (P < 0.01). The absolute change in the flexibility rate was significantly higher at the concave side than at the convex side under both compressive (P < 0.01) and distractive loaded forces (P = 0.046). No significant correlation was found between change in the flexibility rates and preoperative Cobb angle or preoperative curve flexibility.InterpretationFrom a biomechanical point of view, multilevel facetectomy provides proper spinal flexibility to improve the correction rate of posterior adolescent idiopathic scoliosis surgery. The effects are higher at the concave side than at the convex side.     

Assessment of cervical stiffness in axial rotation among chronic neck pain patients: A trial in the framework of a non-manipulative osteopathic management

BackgroundCervical stiffness is a clinical feature commonly appraised during the functional examination of cervical spine. Measurements of cervical stiffness in axial rotation have not been reported for patients with neck pain. The purpose of this study was to investigate cervical spine stiffness in axial rotation among neck pain patients and asymptomatic subjects, and to analyze the impact of osteopathic management.MethodsThirty-five individuals (17 patients) were enrolled. Measurements were carried out for left-right axial rotation using a torque meter device, prior and after intervention. Passive range of motion, stiffness, and elastic-and neutral zone magnitudes were analyzed. Pain intensity was also collected for patients. The intervention consisted in one single session of non-manipulative osteopathic treatment performed in both groups.FindingsA significant main effect of intervention was found for total range of motion and neutral zone. Also, treatment by group interaction was demonstrated for neutral-, elastic zone, stiffness in right axial rotation, and for total neutral zone. Significant changes were observed in the clinical group after intervention, indicating elastic zone decrease and neutral zone increase. In contrast, no significant alteration was detected for the control group.InterpretationsStiffness characteristics of the cervical spine in axial rotation are prone to be altered in patients with neck pain, but seem to be relieved after a session of non-manipulative manual therapeutic techniques. Further investigations, including randomized clinical trials with various clinical populations and therapeutic modalities, are needed to confirm these preliminary findings.     

Manual fixation versus locking during upper cervical segmental mobilization. Part 2: an in vitro three-dimensional arthrokinematic analysis of manual axial rotation and lateral bending mobilization of the atlanto-axial joint

BackgroundThree-dimensional kinematic aspects of coupled motion during manual cervical mobilization have not previously been studied. Using an in vitro 3D-motion analysis method, the kinematic effects of two different segmental techniques for axial rotation and lateral bending mobilization of the upper cervical spine were investigated as a second part of the study (in part one, kinematic effects of flexion-extension mobilization have been investigated).MethodsAxial rotation and lateral bending mobilization of the atlanto-occipital and atlanto-axial segments were analysed in vitro using an electromagnetic tracking device. Local reference frames were defined based on bony reference points that were registered using a 3D-digitizing stylus.Five embalmed and one fresh specimen were analysed. Segmental motion was registered simultaneously in the atlanto-occipital and the atlanto-axial joints during manual mobilization through the full range of axial rotation and lateral bending mobility. The 3D-kinematic aspects during regional mobilization were compared with those during segmental mobilization with manual fixation and during segmental mobilization using a locking technique.ResultsDuring both segmental axial rotation techniques of the atlanto-axial joint, a significant reduction of the coupled lateral bending and flexion-extension motion was observed. The locking technique also induced an increase in the main axial rotation component. During lateral bending mobilization of the atlanto-axial joint, the manual fixation technique reduced the effect on the coupled flexion-extension component significantly.InterpretationsThese results suggest that for manual segmental axial rotation and lateral bending mobilization of the upper cervical spine segmental manual fixation or locking may be preferred in different situations depending on the desired effects. This study brings additional information to the data provided by part 1 of this study on the 3D-arthrokinematic effects of flexion-extension mobilization.     

Physiological effects of physical therapy interventions on lumbar intervertebral discs: A systematic review

Background context: The use of physical therapy has been recommended in the treatment of low back pain based on primarily mechanical and neurophysiological effects. Recent studies have measured the physiological effects of physical therapy interventions, including manual therapy and traction, on the intervertebral discs (IVD), and these findings may have implications for the long-term management or even prevention of low back pain. Purpose: The objective of this systematic review is to investigate the literature regarding possible physiological effects of physical therapy interventions on the intervertebral disc (IVD). Study design: Systematic Review. Methods: A literature search of published articles through December 2014 resulted in the retrieval of 8 clinical studies assessing the influence of physical therapy interventions on the physiology of the IVD. Results: Three studies, including two using animal models, investigated the effects of 30-minute intermittent traction on disc height. One in vivo animal study and two studies using human subjects assessed changes of disc height associated with static traction. Three studies investigated the effects of lumbar spine manipulation and mobilization on changes in water diffusion within the IVD. All studies confirmed, either directly or indirectly, that their respective intervention influenced disc physiology primarily through water flow. Conclusion: Physical therapy interventions may have an effect on the physiology of the IVD, primarily through water diffusion and molecular transport, which are important for the health of the IVD.     

The effects of creep and recovery on the in vitro biomechanical characteristics of human multi-level thoracolumbar spinal segments

Background

Several physiological and pathological conditions in daily life cause sustained static bending or torsion loads on the spine resulting in creep of spinal segments. The objective of this study was to determine the effects of creep and recovery on the range of motion, neutral zone, and neutral zone stiffness of thoracolumbar multi-level spinal segments in flexion, extension, lateral bending and axial rotation.

Methods

Six human cadaveric spines (age at time of death 55–84 years) were sectioned in T1–T4, T5–T8, T9–T12, and L1–L4 segments and prepared for testing. Moments were applied of + 4 to − 4 N m in flexion-extension, lateral bending, and axial rotation. This was repeated after 30 min of creep loading at 2 N m in the tested direction and after 30 min of recovery. Displacement of individual motion segments was measured using a 3D optical movement registration system. The range of motion, neutral zone, and neutral zone stiffness of the middle motion segments were calculated from the moment-angular displacement data.

Findings

The range of motion increased significantly after creep in extension, lateral bending and axial rotation (P < 0.05). The range of motion after flexion creep showed an increasing trend as well, and the neutral zone after flexion creep increased by on average 36% (P < 0.01). The neutral zone stiffness was significantly lower after creep in axial rotation (P < 0.05).

Interpretation

The overall flexibility of the spinal segments was in general larger after 30 min of creep loading. This higher flexibility of the spinal segments may be a risk factor for potential spinal instability or injury.     

Update on Spinal Mobilisations with Leg Movement

Abstract

A case study demonstrates the use of spinal mobilisations with leg movement to treat a patient who presented with low back pain and sciatica. A prone lying technique is demonstrated, however, the author is not suggesting that this new technique should replace the side lying method which was described in 1995. Both have a place in the treatment of patients with low back pain and sciatica.     

Reflex Responses of Neck,Back, and Limb Muscles to High-Velocity,Low-Amplitude Manual Cervical and Upper Thoracic Spinal Manipulation of Asymptomatic Individuals—A Descriptive Study

ObjectiveThe purpose of this research was to determine the extent of reflex responses after spinal manipulative therapy (SMT) of the cervical and upper thoracic spine.MethodsEleven asymptomatic participants received 6 commonly used SMTs to the cervical and upper thoracic spine. Bipolar surface electromyography electrodes were used to measure reflex responses of 16 neck, back, and proximal limb muscles bilaterally. The percentage of occurrence and the extent of reflex responses of these muscles were determined.ResultsReflex responses after cervical SMT were typically present in all neck and most back muscles, whereas responses in the outlets to the arm and leg were less frequent. This trend was similar, although decreased in magnitude, after thoracic SMT.ConclusionReflex responses were greatest after upper cervical SMT and lowest with thoracic SMT.     

The ability of a sustained within-session finding of pain reduction during traction to dictate improved outcomes from a manual therapy approach on patients with osteoarthritis of the hip

Abstract

Objectives: The objectives of this study were to: (1) determine the association of a within-session finding after traction of the hip with self-report of well-being, pain, and self-report of function at 9 weeks; and (2) to determine if the interactions between the within-session finding and the outcome measure are different between groups of patients with hip OA who receive and who do not receive manual therapy.

Methods: Data were retrospectively analysed in 70 subjects who were part of a randomized control trial. Correlation analyses of within-session findings from the initial visit after traction of a concordantly painful hip were compared to self-report measures for function, pain, and well-being at 9 weeks. A comparison of slope coefficients between manual therapy and non-manual therapy groups was performed to determine the interactive aspects of the within-session finding.

Results: Although the correlations for the manual therapy group were higher than for the supervised neglect group, none of the correlational analyses for both groups was strong or significant. Significant differences in the slope coefficients for well-being and pain were found, suggesting that the interactions between the within-session findings and the targeted outcomes were different in the manual therapy group versus supervised neglect group.

Discussion: These findings suggest that within-session findings during the initial evaluation are not strongly related to a positive outcome after manual therapy, although the interaction of the finding of a within-session change and the use of manual therapy is more compelling than the finding in a sample of patients who did not receive manual therapy.     

A patient specific computational biomechanical model for the entire lumbosacral spinal unit with imposed spondylolysis

BackgroundA biomechanical model of the lumbosacral spinal unit between L1-S1 was developed to investigate the behavior of normal and select pathological states. Our aims were to generate predictive structural models for mechanical deformation including critical stresses in the spine components and to investigate the probability of subsequent lumbar spine fractures in the presence of unilateral spondylolysis.MethodsA non-linear three-dimensional finite element pathology-free model of the L1-S1 lumbosacral unit was generated using patient-specific computerized tomography scans and calibrated by comparing it to experimental data of a range of motion modes consisting of flexion, extension, left and right lateral bending, and left and right axial rotation. Unilateral and bilateral pars defects were created on the isthmus of L5 to simulate spondylolysis.FindingsResults showed that under flexion, left lateral bending and right axial rotation, stresses were higher on the contralateral L5 pars-interarticularis, whereas, no significant changes occurred on the left-right isthmus of the L2-L4 and S1. Significant changes in the range of motion compared to the pathology-free model were observed in bilateral spondylolysis not only adjacent to the pars defect area but also in other lumbar spine levels.InterpretationThe proposed pathology-free lumbosacral unit model showed good correlation with experimental tests for all loading cases. In unilateral spondylolysis, a subsequent pars defect was observed within the same vertebra. The overall modeling approach can be used to study different pathological states.