Lordosis Of Lumbar Spine Research Articles

Promoting Regeneration in Degenerative Disc Disease.

The degenerative disc disease has a multifactorial etiology and mechanical stress is one of the most important etiological factor. The purpose of this study was to evaluate the intervertebral disc (IVD) after axial stress diminution from the point of view of its proteoglycan (PG) content, with preoteoglicans (PGs) being very important in the normal function but also in the degenerative or regenerative processes. This is a single-center, prospective, non-randomized study of 38 degenerated intervertebral discs treated with monosegmental or polisegmental posterior lumbar spinal fixation in 27 patients. During surgery, a posterior intervertebral distraction at operated levels was applied. Patients' mean age was 50.77 years and the mean follow-up 28.74 months. Both clinical (visual analog pain scale, Oswestry disability index) and radiological (lumbar spine lordosis, disc thickness) analyses were made before and after surgery. A new method of cartilage analysis, which was also validated for the IVD, delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) was used to determine the PG content before and after surgery for both the intervertebral degenerative disc and control level L1-L2 disc. The clinical features improved significantly. The thickness of the operated discs increased by an average of 1.71 mm postoperatively and remained unchanged in the control group. The lumbar lordosis did not change significantly. In dGEMRIC studies, the discs accumulated in average 410.08 units /cm2 of gadolinium before surgery and 272.45 units/cm2 after surgery, without significant changes in the control group. Our study shows an improvement of PG quantity in degenerated IVD due to a decrease in gadolinium binding seen in dGEMRIC study. Thus, we can ameliorate IVD homeostasis by eliminating mechanical stress, which could be a step towards the process of disc regeneration.

Quantitative evaluation of correlation between lumbosacral lordosis and pelvic incidence in standing position among asymptomatic Asian adults: a prospective study

The determination of lumbopelvic alignment is essential for planning adult spinal deformity surgery and for ensuring favorable surgical outcomes. This prospective study investigated the correlation between the lumbar section of lumbar spine lordosis and increasing pelvic incidence in 324 Asian adults with a mean age of 55 ± 13 years (range: 20–80 years), comprising 115 male and 209 female volunteers. Participants were divided into three groups based on pelvic incidence (G1, G2, and G3 had pelvic incidence of < 45°, 45–55°, and ≥ 55°, respectively). We determined that distal and proximal lumbar lordosis contributed differentially to the increase in pelvic incidence, whereas the lordosis ratio of the L3–L4 and L4–L5 segments mostly remained constant. The mean contribution ratio of the segmental lordosis from L1 to S1 was as follows: L1–L2, 2.3%; L2–L3, 11.7%; L3–L4, 18.1%; L4–L5, 25.2%; and L5–S1, 42.7%. Pelvic incidence had a stronger correlation with proximal lumbar lordosis than did distal lumbar lordosis. The ratios of proximal lumbar lordosis to distal lumbar lordosis were 37.8% in G1, 45.8% in G2, and 55.9% in G3. These findings serve as a reference for future lumbar spine correction or fusion surgery for Asian adults.

Reliability and Validity of the Evaluation of Lumbar Spine Lordosis Using a Flexible Curve Ruler

Reliability and Validity of the Evaluation of Lumbar Spine Lordosis Using a Flexible Curve Ruler

Segmental Contributions to Lumbar Lordosis: A Computed Tomography Study.

The aim of this study was to determine the contribution of individual vertebral body lordosis to lumbar lordosis and establish the relationship of vertebral body lordosis to the pelvic incidence (PI). One-hundred and two computed tomography (CT) scans on patients free of radiographic disease were measured for PI and segmental lordosis of both bone and disc from L1 to sacrum. Correlative analysis and analysis of variance (ANOVA) were used to identify contribution from bone and disc to lordosis. The mean total bony lordosis was 10.8° (SD 11.5°), mean total disc lordosis was 36.3° (SD 9.9°), and mean combined lordosis was 47.1° (SD 10.0°). The mean PI of the entire cohort was 49.2° (SD 9.3°). One-way ANOVA demonstrated a significant difference between the PI strata in total bony lordosis values with a mean difference of 14.0° between low and high PI cohorts (P < .001) and also mid- and high PI cohorts of 9.9° (P = .008). Overall, distal lordosis represented 80.8% of the total lordosis. In the proximal lumbar segments, the mean contribution from bone was -4.0° (SD 6.8°) and the mean contribution from disc was 13.6° (SD 6.0°). In the distal, the mean contribution from bone was 14.7° (SD 6.5°) and from disc, 22.7° (SD 6.2°). The contribution to lordosis from the vertebral bodies is greater in the proximal lumbar spine with increasing PI. With low PI, the proximal vertebral bodies demonstrate reduced contribution to lordosis and in some instances are kyphotic. Future research efforts should place greater emphasis on providing segmental rather than just global analysis of alignment. Restoration of lumbar spine lordosis should take into account the variation in segmental lordosis contributions as it relates to PI.

Comparison of Spinal Sagittal Curvatures, Functional Status and Quality of Life of Medical Secretaries with or without Upper or Low Back Pain

Amaç: Tıbbi sekreterlerde sırt ve/veya bel ağrısı sık görülmektedir. Bu çalışmanın amacı, sırt veya bel ağrısı olan sekreterler ile olmayan sekreterlerin omurga eğriliği, omurga hareketliliği, disabilite ve yaşam kalitesi düzeylerini karşılaştırmaktır. Materyal ve Metod: Çalışmaya aynı hastanede çalışan 111 tıbbi sekreter dahil edildi. Tıbbi sekreterler sırt ağrısı olan ve olmayan olarak iki gruba; bel ağrısı olan ve olmayan olarak diğer iki gruba ayrıldılar. Omurganın sagittal düzlemdeki şekli ve hareketliliği “Spinal Mouse™” isimli non-invaziv bir alet kullanılarak ölçüldü. Ölçümler ayakta dururken ve oturma pozisyonunda ayrı ayrı tekrarlandı. Ağrı şiddeti Vizüel Analog Skala (VAS) ile; fonksiyonel durum Oswestry Disabilite Ölçeği (ODÖ) ile; yaşam kalitesi ise Notthigham Sağlık Profili (NSP) kullanılarak değerlendirildi. Bulgular: Çalışmaya dahil edilen tıbbi sekreterlerin (75 kadın/36 erkek) yaş ortalaması 30.73±5.74 yıl idi. Sırt ağrısı olan 51 sekreterin VAS ortalaması 5.47±2.67; bel ağrısı olan 63 sekreterin VAS ortalaması 5.52±2.66 idi. Sırt ağrısı olan sekreterlerin oturur pozisyonda ve ayakta iken ölçülen torakal kifoz açısı, sırt ağrısı olmayan sekreterlere göre daha yüksekti (p˂0.032, p˂0.001). Her iki grup arasında oturur pozisyonda ve ayakta iken ölçülen torakal vertebra hareketliliği açısından anlamlı fark yoktu. İki grup arasında NSP-total, NSP-enerji, NSP-ağrı, NSP-duygusal reaksiyonlar ve NSP-fiziksel hareketlilik alt grupları arasında anlamlı fark vardı (p˂0.001, p=0.001, p˂0.001, p=0.001, p=0.001). Bel ağrısı olan sekreterlerin ayakta duruşta ölçülen lomber lordoz açısı, bel ağrısı olmayanlara göre daha düşüktü (p˂0.001). Her iki grup arasında oturur pozisyonda iken ölçülen lomber lordoz açısı ile oturur pozisyonda ve ayakta iken ölçülen lomber vertebra hareketliliği açısından anlamlı fark yoktu. İki grup arasında ODÖ, NSP-total, NSP-enerji, NSP-ağrı ve NSP-fiziksel hareketlilik alt grupları arasında anlamlı fark vardı (p˂0.001, p=0.025, p=0.042, p=0.039, p=0.019). Sonuç: Spinal Mouse™ kullanılarak yapılan ölçümlerde omurga hareketliliğinde fark olmamasına rağmen; sırt ağrısı olan sekretelerde torakal omurgada kifoz artışı, bel ağrısı olanlarda da lomber omurgada lordoz azalması olduğu görülmüştür. Sırt ve bel ağrısının varlığı fonksiyonel durumu ve yaşam kalitesini olumsuz etkilemektedir.

Effect of Chronic Low Back Pain on Lumbar Spine Lordosis During Sit-to-Stand and Stand-to-Sit

ObjectiveThis study aimed to evaluate lumbar lordosis during sit-to-stand (STS) and stand-to-sit (SIT) in individuals with and without chronic nonspecific low back pain (CNLBP). The second objective was to investigate sex-related differences in lumbar lordosis. MethodsTwenty-six patients with CNLBP and 26 controls were recruited. Controls were matched with cases using a frequency matching method. Reflective markers were placed over the spinous process of T12, L3, S2, and the anterior and posterior superior iliac spines. The participants were instructed to stand up at a self-selected pace and maintain their normal upright standing posture for 3 seconds, and then sit down. Kinematic data were recorded at a sampling frequency of 100 Hz using a motion capture system. Lumbar lordosis angle was calculated from the intersection between the line joining T12 and L3, and the line joining L3 to S2. ResultsLumbar lordosis was decreased in patients with CNLBP during STS and SIT compared with the asymptomatic group (mean difference = 2.68°-9.32°; P ≤ .005). Furthermore, no differences were seen in lumbar lordosis at starting position between CNLBP and asymptomatic groups during STS and SIT (mean difference = 2.68°-3.75°; P ≥ .099). Interestingly, the magnitude of the effect size suggested that the difference in lumbar lordosis values between female and male participants was relatively large (Cohen's d = -1.81 to 0.20). ConclusionDecreased lumbar lordosis in patients with CNLBP during STS and SIT could be considered as an important point during rehabilitation. Moreover, the present study showed that there is a sex-related difference among women and men in lumbar lordosis during STS and SIT tasks.

The Effect of Restoration of Lumbar Spine Lordosis During Fixation on Clinical Outcome of Patients

The Effect of Restoration of Lumbar Spine Lordosis During Fixation on Clinical Outcome of Patients

X-ray parameters of low segmental lordosis of lumbar spine and their relation with sacral and pelvic tilt in frontal plane in patients with sacroiliac joint dysfunction

X-ray parameters of low segmental lordosis of lumbar spine and their relation with sacral and pelvic tilt in frontal plane in patients with sacroiliac joint dysfunction

Postoperative Change of Thoracic Kyphosis after Corrective Surgery for Adult Spinal Deformity.

Introduction Correction of lumbar lordosis is the primary goal of surgical treatment of adult spinal deformity. However, only limited research has evaluated the effects of this correction on the adaptive curvature of the thoracic spine. The purpose of this study is to evaluate the change in thoracic curvature after corrective surgery to restore lumbar lordosis in patients with adult spinal deformity. Methods We completed a retrospective analysis of the radiological data of 65 patients, ≥50 years old, who underwent corrective surgery of lumbar spine lordosis from any level below T8 to the ilium. Patients with insufficient correction, defined by a pelvic incidence minus lumbar lordosis angle (PI-LL) > 10°, were excluded, with the data of 43 patients included in the analysis. The following radiological measures of spinal alignment were measured at three time points, preoperatively, on the first day of standing postoperatively and at 2 years post-surgery: sagittal vertical axis (SVA), lumbar lordosis (LL), thoracic kyphosis (TK), pelvic tilt (PT), and PI-LL. Results Postoperative change in TK was correlated to preoperative TK and age. The increase in TK was larger for patients <75 years of age, increasing from 23.1° to 38.0° after surgery and to 46.7° at 2-years postoperatively. In contrast, for patients >75 years, TK remained largely unchanged at 37.8° just after surgery but increased substantively to 50.1° at the 2-year follow-up. The postoperative change in TK immediately after surgery was determined using equation “predict change in TK = −0.21 × age − 0.6 × preoperative TK + 41.8” by multiple regression analysis. Conclusions Reciprocal change in TK after lumbar spine correction is correlated to preoperative TK and age.

Comparison of three different posterior fixation techniques in transforaminal lumbar interbody fusion for two-level lumbar degenerative diseases: At a mean follow up time of 46 months

ObjectivesThis study sought to retrospectively compare three different posterior fixation techniques in transforaminal lumbar interbody fusion for two-level lumbar degenerative diseases. Patients and methodsThis was a retrospective single-center study including 84 patients who underwent TLIF instrumented with unilateral pedicle screws (UPS), unilateral pedicle screws plus contra-lateral translaminar facet screws (UPSFS), or bilateral pedicle screws (BPS) between June 2008 and May 2012. These patients were divided into three groups: UPS (n=22), UPSFS (n=28) and BPS (n=34) group. Operative time, blood loss, length of hospital stay, hospital bill, fusion status and complications were recorded and analyzed statistically. Visual analog scale (VAS), Oswestry Disability Index (ODI), and Japanese Orthopaedic Association Scores (JOA) were used to assess the preoperative and postoperative pain and functional outcome. Sagittal aligment was evaluated by the segment lordosis (SL) and whole lumbar spine lordosis (LL). ResultsThe mean follow up duration was 46.2 (ranging from 36 to 60) months. A significant decrease occurred in operative time, blood loss and hospital bill in UPS and UPSFS group, compared with BPS group (p<0.05). The average postoperative VAS, ODI and JOA scores improved significantly in each group than the preoperative counterparts (p<0.05), however, there were no significant difference between groups at any follow-up time point (p>0.05). No statistically difference was detected regarding fusion rate and complication rate between groups (p>0.05), except the screw/rod failure rate (p<0.05). Radiographic analysis showed that the LLs in all these groups got improved (p<0.05) and the SLs maintained (p>0.05). ConclusionUPS or UPSFS instrumented TLIF could achieve satisfactory mid-term clinical outcome comparable to BPS’s, with less surgical time, less blood loss, and lower cost; UPS should be prudently performed for two-level cases in case of lower fusion rate, and cannulated screws should be replaced by stronger solid screws in UPSFS to reduce facet screw breakage.

Distribution of Schmorl nodes in the lumbar spine and their relationship with lumbar disk degeneration and range of motion.

A kinematic magnetic resonance imaging study. To investigate the distribution of Schmorl nodes (SNs) in the lumbar spine in healthy adults, and determine the association with lumbar disk degeneration and lumbar spine motion. SNs have been associated with several pathologies of the lumbar spine, although it has been demonstrated that they also occur in the healthy adult population without a clearly identified cause. A thorough understanding of SN distribution may help reveal reasons for their formation. How disk degeneration and lumbar spine motion relate to SNs is poorly understood. Kinematic magnetic resonance images (0.6 T) were available for 1179 healthy individuals from 15 to 85 years of age. Spine specialists performed computer-based measurements. All parameters were measured and calculated automatically using the eRAD PACS Viewer (eRAD Inc., version 6.2.1.1). Lumbar disk degeneration was documented according to the Pfirrmann classification system. Lumbar spine lordosis was quantified as the angle between the inferior endplate of L1 and superior endplate of S1. The level of significance was defined as P ≤ 0.05. The distribution of SNs along the lumbar spine and their relationship with age and sex was investigated using the single factor analysis of variance χ test. The relationship between SNs, age group, disk location, and overall grades of lumbar disk degeneration were investigated by multiple logistic regression analysis. Lumbar spine motion was compared between patients with and without SNs via independent t test among 585 individuals with qualified kinematic images. Multiple logistic regression analysis was performed on associations of lumbar motion range among the SN population. The prevalence of SNs in our study population was 28.4%, and SNs were observed to be present more frequently in males (34.6%) than in females (20.2%) (ρ< 0.01). There was no significant difference in the incidence of SNs between age groups (ρ= 0.18). SNs were more common at the L2 and L3 vertebral bodies (14.3% and 14.4%), whereas SNs were least common at S1 vertebral bodies (1.5%). The highest incidences of SNs presentation was on disks with degeneration grade III (41.9%) and grade IV (45.3%). SN occurrence, aging, and disk location were positively correlated with lumbar disk degeneration grade. The lumbar spine range of motion was significantly different between individuals with and without SNs (31.4° vs. 37.9°, ρ< 0.01). The frequency of SNs was associated with decreased lumbar range of motion in all age groups except 51 to 60 years and 61 to 70 years. SNs have a high incidence in individuals without persistent lumbar disorders and were found in disks at all degrees of degeneration. SNs occurrence were positively associated with lumbar disk degeneration In addition, the presence of SNs was correlated with decreased overall lumbar motion across all age groups.

Comparison between Posterior Laminectomy and Discectomy Followed by Coflex and Transforaminal Lumbar Interbody Fusion in Treating Lumbar Disc Herniation: A Minimum 2-year Follow-up Study

Introduction The aim of the study is to compare the clinical outcomes of posterior decompression combined with interlaminar dynamic reconstruction-Coflex or transforaminal lumbar interbody fusion in treating lumbar disc herniation with instability. Materials and Methods A comparative study was performed on 13 male and 31 female patients (L3/4 18, L4/5 26) diagnosed as lumbar disc herniation with instability, with an average age of 53.6 years (range, 39-73 years), of which all cases were followed up at least 2 years. All patients were treated with interlaminar dynamic fixation with Coflex system (Coflex group, 19 cases) or transforaminal lumbar interbody fusion (TLIF group, 25 cases). The results were assessed by medical cost, operation time, blood loss, and Oswestry disability index (ODI). The range of motion (ROM) and intervertebral height of index and adjacent segments and the Lordosis of lumbar spine were measured before operation and last follow-up. Results The medical cost operative time and blood loss were significantly decreased in Coflex group than those in TLIF group. At the last follow-up, the ODI of groups Coflex and TLIF were significantly improved when compared with the preoperative values ( p &lt; 0.05). At last follow-up, a better range of motion and intervertebral height of index and adjacent segments were found in Coflex group. However, the reoperation rate of Coflex group was higher than that of TLIF group ( p &lt; 0.05). Conclusion Posterior decompression combined with Coflex has the same midterm effectiveness as transforaminal lumbar interbody fusion in treating degenerative lumbar disc herniation with instability and Coflex has less traumatic and recovery time, somewhat protective effect on the adjacent segments. However, the rate of reoperation is slightly higher in Coflex Group. Disclosure of Interest None declared

Posterior one-stage resection for intra- and extra-dumbbell-shaped tumor of the lumbar spine

Objective To investigate the surgical technique and to evaluate the outcome of one stage resection for intra - and extra - dumbbell - shaped tumor of the lumbar spine.Methods 10 patients with dumbbell - shaped tumors of lumbar spine from 2006 to 2011treated surgically were analyzed retrospectively.The tumor located at the level of L4-5 in 6 cases,L2-3 in 3 cases and L5 - S1in 1case.Back pain and radicular neuralgia along the affected nerve root were the main clinical manifestation.There were three surgical approaches according to the main location of the tumors included para - middle approach through exra - par in 3 cases,posterior laminectomy in 4 cases,and posterior laminectomy and facetactomy plus instrumentation and fusion in 3 cases respectively.Results 10 operations had been performed with gross total of tumor resection in all cases.The timing of procedures was from 1.5 to 4.1hours.The volume of bleeding during operation was around 90 to 300 ml.There was no surgical complications happened.Clinically,the symptoms of back pain and radicular neuralgia prior to operation were relieved or disappeared.The histological examination showed Schwannoma in 9 cases,and neurofibroma in 1case.The period of follow - up was ranged from 3 months to 5 years.There was 1patient with pain surrounding the incision area happened in 2 months post - operation and that was disappeared 8 months post - operation.Neurological status had been stable during the followed - up period. The recurrence rate was 0. The alignment and lordosis of lumbar spine was intact during the follow - up.Conclusions The Schwannoma and neurofibroma were the most common pathological type of dumbbell - shaped tumor located at the lumbar spine and that can be well revealed and removed through appropriate approaches according to the pre operation MRI manifestation. Key words: Spinal cord neoplasms; Schwannoma; Spine; Microsurgery

Evaluation of Spinal Internal Loads and Lumbar Curvature under Holding Static Load at Different Trunk and Knee Positions

A study was performed to investigate how different trunk and knee positions while holding static loads affect the lumbar curvature and internal loads on the lumbar spine at L4-L5. Ten healthy male subjects participated in this study. Two inclinometers were used to evaluate the curvature of lumbar spine, lordosis, while a 3D static biomechanical model was used to predict the spinal compression and shear forces at L4-L5. Eighteen static tasks while holding three level of load (0, 10 and 20 kg), two levels of knee position (45 and 180 degrees of flexion) and three levels of trunk position (neutral, 15 and 30 degree of flexion) were simulated for 10 healthy male subjects. The results of this study revealed that the lordosis of lumbar spine changed to kyphosis with increasing weight of load from 0 to 20 kg in trunk flexion position (p<0.05), but in squatting position (45 degrees knee full flexion) the higher load did not affect the curvature. The results of this study suggested, at a more flexed trunk and standing position with higher loads both external moment and internal loads increased significantly at L4-L5 level but with 45 knee flexion external moment and compression force increased and shear force decreased significantly (p < 0.05). Subjects made more effort to maintain stability of the body in squat position. The highest external moment and compression force were computed at flexed knee and trunk position with highest loads. Hence holding weight in this position must be avoided by implementing ergonomic change to the workplace.

A buckling analysis related to adolescent idiopathic scoliosis

Objectives. To develop and validate a new method of predicting the neutral lumbar spine curve from external (non-invasive electrogoniometer) measurements.Background. Non-invasive techniques for lumbar spine geometry prediction suffer from a lack of a complete geometry description, problems with applicability to field conditions, or both.Methods.The study consisted of three steps. First, utilizing lateral imaging (MRI and X-ray pictures) of the lumbosacral junction, the torso geometry was described using measures of lumbar lordosis via the Cobb method. Second, the relationship between imaging based measurement of lumbar spinal curvature and externally measured torso flexion angle in the sagittal plane using a goniometer was determined. Finally, method validation was performed with an independent set of nine subjects. The predicted lumbar spine curve was determined and the prediction errors were analyzed against the measured curves from digitized lateral X-ray images of the lumbosacral junction.Results.The shape of the lumbar curve was described as function of three externally measured parameters. The lumbar spine Cobb angle, segmental centroid positions (S1−T12), and segmental orientations were predicted from the external lumbar motion monitor measurements, with average precisions of 5.8°, 4.4 mm, and 3.9°, respectively.Conclusions.The position and orientation of each segment (vertebrae and disc), along with the lumbar spine lordosis, can be predicted in the neutral posture using data from back angular measurements.RelevanceThe consideration of the spine as a curve is necessary to accurately quantify and describe the forces acting along the (lumbar) vertebral column for any given loading. The method could be a very useful prediction tool for industrial and laboratory experiments, as well as analytical models.

Two-level posterior lumbar interbody fusion for degenerative disc disease: improved clinical outcome with restoration of lumbar lordosis

Background context Although posterior lumbar interbody fusion (PLIF) for degenerative lumbar diseases is routine, there are few reports on double-level PLIF. Purpose To evaluate the clinical outcomes of double-level PLIF. Study design/setting A retrospective study of operated cases in Gifu, Japan. Patient sample Nineteen patients (8 men and 11 women, 59.5±10.2 years) who underwent double-level PLIF between 1996 and 2001. Outcome measures Operation time, blood loss, complications, the Japanese Orthopaedic Association (JOA) score for back pain and lumbar sagittal alignment were evaluated. Methods Patients were examined retrospectively at follow-ups of 3.6±1.7 years. Primary diseases were spondylolisthesis, spinal canal stenosis, degenerative scoliosis and herniated intervertebral disc. Fusion areas were L3 to L5 in 15 cases and L4 to S1 in 4 cases. Results The mean JOA score increased from an initial score of 12.9±3.5 to 21.3±4.9 at the final follow-up. There was a positive correlation (R=0.718, p<.001) between the increase in lordotic angle and the increase in the JOA score. Several parameters suggested that the surgical invasiveness was not minimal. Conclusion Double-level PLIF provided satisfactory results and preserved lumbar spine lordosis.

The prediction of lumbar spine geometry: method development and validation

To develop and validate a new method of predicting the neutral lumbar spine curve from external (non-invasive electrogoniometer) measurements. Non-invasive techniques for lumbar spine geometry prediction suffer from a lack of a complete geometry description, problems with applicability to field conditions, or both. The study consisted of three steps. First, utilizing lateral imaging (MRI and X-ray pictures) of the lumbosacral junction, the torso geometry was described using measures of lumbar lordosis via the Cobb method. Second, the relationship between imaging based measurement of lumbar spinal curvature and externally measured torso flexion angle in the sagittal plane using a goniometer was determined. Finally, method validation was performed with an independent set of nine subjects. The predicted lumbar spine curve was determined and the prediction errors were analyzed against the measured curves from digitized lateral X-ray images of the lumbosacral junction. The shape of the lumbar curve was described as function of three externally measured parameters. The lumbar spine Cobb angle, segmental centroid positions (S(1)-T(12)), and segmental orientations were predicted from the external lumbar motion monitor measurements, with average precisions of 5.8 degrees , 4.4 mm, and 3.9 degrees , respectively. The position and orientation of each segment (vertebrae and disc), along with the lumbar spine lordosis, can be predicted in the neutral posture using data from back angular measurements. The consideration of the spine as a curve is necessary to accurately quantify and describe the forces acting along the (lumbar) vertebral column for any given loading. The method could be a very useful prediction tool for industrial and laboratory experiments, as well as analytical models.

Luigi Boccherini and the Barocco cello: an 18th century striking case of occupational disease

AbstractThe aim of this paper is to elaborate an ergonomic model based on the study of acquired muscle‐skeletal lesions related to Boccherini's intensive activity as Barocco cellist. The body of the famous musician was submitted to external examination, macroscopic analysis and radiographic study. Palaeopathological studies of the skeleton showed a considerable number of changes such as severe rhizoarthritis of the right thumb, heavy epicondylitis of the left elbow, loss of physiological cervical and lumbar spine lordosis and high thoracic left scoliosis with maximum on T3‐T4. A case of tibiae valgae was diagnosed at the level of the legs. The acquired muscle‐skeletal lesions found seemed to be correlated to Boccherini's cello activity. Direct observation of a present‐day cellist allowed us to better understand how repetitive strain injuries were responsible for the situation which appears in the ergonomic model described. Copyright © 2003 John Wiley &amp; Sons, Ltd.

Coordination between the lumbar spine lordosis and trunk angle during weight lifting

Objective. To analyze the coordination of the lumbo-sacral angle (lumbar spine lordosis) and the trunk inclination during lifting of different loads. Study design. Kinematic data of spine motion were analyzed. The parameters characterizing the relationships between the lordosis and the trunk inclination angle were estimated. Background. The shape of the spine has been analyzed mostly for static or quasi-static conditions. The parameters relating the lumbar spine lordosis and trunk inclination in dynamics have not been analyzed. Methods. Healthy subjects performed unconstrained weight lifts from ground to mid-thigh level. Kinematic data were derived from the tracking of markers (light-emitted diodes) placed over the spine and pelvis using an OPTPTRAK system. The relationship between lordosis and trunk inclination was analyzed. Results. The relationship between lumbar spine curvature (lumbo-sacral angle or lordosis) and trunk inclination during weight lifting was described by an exponential function with three parameters. These were the lordosis extremes associated with the horizontal and vertical positions of the trunk and the trunk inclination when lordosis equals zero. The absolute value of the lordosis angle decreases at the onset of the extension phase of lifting when the load increases, implying active reaction of musculosceletal system to increasing load. Conclusions. The changes in the lordosis and trunk inclination are strictly correlated impiying that the nervous system actively coordinates the degrees of freedom of the spine, providing an inter-joint synergy. Relevance The study of factors influencing the lumbar spine curvature is essential to the understanding of lumbar spine function and, in particular, to understanding the control of multiple degrees of freedom of the trunk (the redundancy problem). To address these problems, we analysed the relationship between the lumbo-sacral angle and the load lifted.

The psoas major muscle: A three-dimensional geometric study

The purpose of this study was to use anatomical data obtained from cadavers, and geometrical scaling data obtained from MRI scans of living subjects, to assess the line of action and mechanical function of the psoas major muscle in three dimensions about each lumbar spine level. In addition, the line of action of the psoas major was documented as a function of lordosis. A total of seven cadavers were dissected from which fibre/tendon architecture was measured, while MRI scans were performed on 15 males to obtain centroid paths and area scales of the muscle over its length. In this way, the curving path of muscle line of action was accommodated together with force and moment predictions that recognized the presence of a tendon at lower lumbar levels (up to L3 in some subjects) significantly increasing the stress. Results confirm that the mechanics of the psoas cannot be adequately represented with a series of straight line vectors from vertebral origins to insertion. Moreover, the mechanical action of the psoas major does not change as a function of lumbar spine lordosis as the muscle path of action changes in accordance with changes in spine posture. Functionally, contrary to claims, the psoas cannot act as a ‘derotator’ of the spine, does not impose large shear forces on the spine in any posture except at L5-S1, and cannot have major affects to ‘control lordosis’. It has the potential to stabilize the lumbar spine with compressive loading and with bilateral activation, to laterally flex it, and can create large anterior shear forces but only at L5-S1.