Spinal Alignment and Low Back Pain Indicating Spine Shape Parameters(Pathogenesis) Part 3

Parameters of spinal alignment

Three-way ANOVAs revealed significant within-subjects effects for only a few video raster stereography parameters of the spinal alignment. Pelvis torsion (P-Tors) and lumbar lordosis angle (LA-max) showed significant changes for the total of the low back pain patients – a group statistically verified – manifesting themselves in pelvis position correction (-0,6°; F=5,145; p=0,025) and lumbar spinal erection (-0,7°; F=6,548; p=0,012), respectively (tab. 7).

Tr-Inc [mm]

Tr-Imb [mm]

P-Tilt [mm]

P-Tors [dgr]

KA-max [dgr]

LA-max [dgr]

Rot-rms [dgr]

Side-rms [mm]

LBP t1 total









± SD









LBP t2 total









± SD













-0,6 *


-0,7 *





















Table 7. Spine shape parameters before (t1) and after (t2) the exercise program for the total (n=107) of low back pain patients (within-subjects effect: p<0,05 *, p<0,01 **, p<0,001 ***)

Changes in the sagittal plane were depending on gender (interaction: F=6,651; p=0,011), but not on age (interaction: F=2,596; p=0,110). Naturally, there were differences in the lumbar lordosis angle (LA-max) between males (t1: 31,6° ± 7,2°; t2: 31,8° ± 7,6°) and females (t1: 41,3° ± 8,0°; t2: 40,0° ± 8,0°) (between-subjects effect: F=25,305; p<0,001), but there was no significant difference between younger and older patients (between-subjects effect: F=2,420; p=0,123).

Changes of pelvis torsion (P-Tors) were neither depending on gender (interaction: F=0,041; p=0,840) nor on age (interaction: F=0,582; p=0,447). There were no significant differences between males and females in the pelvis torsion (between-subjects effect: F=0,353; p=0,554), and also not between younger and older patients (between-subjects effect: F=0,642; p=0,425).

Differences from pre- to post-test for the total of the examined low back pain patients (n=107) in any other spine shape parameter did not reach significance levels (within-subjects effects: p>0,05) (tab. 7). And there were no significant between-subjects effects for gender (p>0,05) or age (p>0,05), except for the trunk inclination, where older people showed significantly larger values than younger persons (F=13,063; p<0,001). Furthermore, there were no significant interactions between the within-subjects factor (treatment) and the between-subjects factors (gender and age), neither for trunk inclination (Tr-Inc), trunk imbalance (Tr-Imb), pelvis tilt (P-Tilt), and thoracic kyphosis angle (KA-max) nor for the vertebral side deviation (Side-rms) or the vertebral rotation (Rot-rms) (p>0,05).

Looking for specific adaptations of spinal alignment, bivariate correlations of alterations -maybe corrections – of spine shape parameters with extra-ordinary deviations (out-layers of the standard deviation interval before the start of the exercise program) in the frontal plane revealed significant correlation coefficients for trunk imbalance (r=0,40; p=0,021; n=33), pelvis tilt (r=0,43; p=0,038; n=23), and pelvis torsion (r=0,72; p<0,001; n=26). There were no significant correlation coefficients for any other spine shape parameter, neither for the sagittal plane nor for the coronal plane, in this specific pre-post-analysis investigating parameter changes depending on the initial state prior to the exercise intervention.

Taking account of the alterations of spine shape parameters additional to the peak force increases, a linear multiple regression model explained the total variance of pain decrease (R=0,399; R2=16%) better than using only peak force increases as predictors (R=0,292; R2=9%). Only trunk imbalance contributed significantly as a predictor (P=0,248; p=0,036) to explain pain decrease.


Cross-sectional findings

A literature review from the beginning of the 21st century did not come to a conclusive position of evidence (Bernard, 2002). Are there any correlations between posture or spinal mal-alignment and muscle function deficits connective with low back complaints? Univariate investigations – using video raster stereography or not – could not confirm these expectations (Heckmann et al., 2008; Nourbakhsh, Arabloo & Salavati, 2006). But in the field of physiotherapy or manipulative medicine and respective treatment as well as diagnostic procedures of low back pain (LBP) this assumption is considered to be a major guide line for therapy interventions (Lewit, 1991; Seeger et al., 1997).

There is some evidence for the relevance of psychosocial factors influencing the development and the progredience of low back pain. Furthermore, chronification and behavioral aspects of individual coping strategies could be established to be predictive factors for a treatment success (Hildebrandt et al., 1997). But with respect to organic signs, low back pain is considered to be unspecific. Pain is not assigned to structural correlates. Radiographic findings indicate the cause of low back pain only accidentally (Waddell et al., 1980). From an organic point of view, spinal instability seems to be a major risk factor, and probably might be a criterion for diagnosis procedures and therapy interventions (Panjabi, 1992).

According to this instability hypothesis, significant associations could be verified between low back pain and functional deficits of trunk muscle peak force (Cady et al., 1979; Denner, 1997; McNeill et al., 1980) and neuromuscular coordination patterns (Richardson, Hodges & Hides, 2004). Resulting deconditioning syndromes might not only be accompanied by functional disorders, but also by spinal mal-alignment and postural abberations (Muller, 1999).

Some epidemiological reviews or radiographic cross-sectional and follow-up studies extracted frontal plane asymmetries and a flatter lumbosacral transition as anthropometric risk factors for the development and progredience of low back pain (Adams, Mannion & Dolan, 1999; Balague, Troussier & Salminen, 1999; During et al., 1985; Harrison et al., 1998; Masset, Piette & Malchaire, 1998; Nissinen et al., 1994).

As a main result, the present investigations could confirm these findings from the literature by means of multivariate analysis approaches and with the help of a non-invasive spine shape reconstruction device. Using video raster stereography, particular spine shape parameters were identified to be associated with low back pain (tab. 3 and tab. 4). Patients with chronic low back pain showed larger values for trunk imbalance (Tr-Imb: p<0,01) and trunk inclination (Tr-Inc: p<0,001) compared to pain free volunteers (tab. 5). Trunk inclination should be considered to be due to the higher age of the patients sample (Gelb et al., 1995; Kobayashi et al., 2004; Takeda et al., 2009), but trunk imbalance remained as an indicator variable to identify low back pain (Schroder, Stiller & Mattes, 2010; 2011). Additionally, female patients showed higher values in the parameter pelvis torsion (P-tors: p<0,001), and male patients had a flatter lumbar lordosis (LA-max: p<0,01), respectively (fig. 4) (Schroder, Strubing & Mattes, 2010). These findings were in a line with earlier studies based on radiological methods or mathematical models, respectively (During et al., 1985; Harrison et al., 1998).

Those recent results provide the idea that spinal mal-alignment should be associated with low back pain. Spine shape abberations might be one organic risk factor for the development of low back pain, but – on the other hand – it might also be a symptom of deconditioning processes in chronic low back complaints, as is well known for deficits of muscle function (Cady et al., 1979; Denner, 1997; 1999; McNeill et al., 1980).

Reconditioning and spinal alignment

Referring to systematic associations between spinal mal-alignment or aberrations of ‘normal’ spine shape and back complaints in chronic low back pain patients described above, we conducted a longitudinal study to analyse adaptations of an individualized exercise program. The exercise program was determinded by individual spine shape parameter findings, muscle function findings, and anamnestic data related to individual back complaints – comparable to programs based only on functional profiles of trunk muscle performance, evaluated earlier (Denner, 1997). Patients were meant to face individually composed tasks to generate almost individual adaptations – with an idea of treatment specificity.

In the present study, clinical outcome variables and muscular function parameters increased like they did in comparable studies using intensive muscle activation (Denner, 1999; Mannion et al., 2001a; 2001b; 2001c; Uhlig, 1999). Low back pain patients started the exercise therapy with a pain state of 3,8 (±2,3) points, in terms of Borg’s CR10 scale meaning a back pain level from moderate to strong. Pain decreased to 2,3 (±1,8) points, meaning a pain level from very weak to moderate. These decreases were accompanied by peak force increases ranging from about 20% to approximately 40% (fig. 5), assigning that kind of reconditioning process described elsewhere for low back patients who went through an active rehabilitation program (Denner, 1997; 1999; Mannion et al., 2001a; 2001b; 2001c; Schroder et al., 2009). Multivariate analysis procedures seeking for a direct correlation between pain decrease and muscle function increases could not reveal significant coefficients (R=0, 292). These findings were in a line with earlier investigations, where a correlation coefficient of r=0,20 (p=0,60) could be established, which was also not suitable to support an assumption of a direct dependency between clinical out-come and muscle function state (Mannion et al., 2001b). Psychological factors, like awareness of increased muscle function and re-established self-confidence, were assumed to be reasonable mediators between decreases of pain or increases of health state parameters and increased muscle function and performance parameters (Mannion et al., 2001c).

Additionally, systematic and significant spine shape alterations – apparent in lumbar erection and correction of pelvis asymmetries – could be verified (tab. 7), comparable to earlier investigations (Schroder et al., 2009). With respect to the knowledge of inter- individual spine shape variability and intra-individual variations in repeated measurements of spinal alignment (Jackson et al., 2000) known as ‘margin error’ in pre-post-analyses (Weifi, Dieckman & Gerner, 2003; Weifi & Klein, 2006) these small changes of pelvis torsion (P-tors: -0,6° ; p=0,025) and lumbar lordosis angle (LA-max: -0,7°; p=0,012) were interpreted as relevant and statistically significant effects, following an active exercise program based on individual findings and using specific treatment elements, like a reasonably high training intensity (Dalichau et al., 2005; Denner, 1997; 1999; Uhlig, 1999) and the special coordination patterns for deep trunk muscles known as Segmental Stabilization Training (Richardson, Hodges & Hides, 2004).

Unfortunately, the evidence of specificity of those exercise induced adaptations was still lacking. On the one hand, adaptations of spine shape parameters in the frontal plane (trunk imbalance, pelvis tilt, pelvis torsion) were greater the more abnormal these values were before the treatment (r=0,40 to 0,72; p<0,05), but on the other hand, pain reduction could not be explained sufficiently, neither by increases of muscle function (R=0,292) nor by corrections of spinal mal-alignment (R=0,256), nor by the total of all parameters, muscle function and spinal alignment (R=0, 399).

Since correlations between clinical out-come variables and functional adaptations of trunk muscle peak force had rarely been investigated, correlations between pain decrease and alterations in the spinal alignment – with a focus on the monitoring of low back pain intervention and using video raster stereography – had as yet not been investigated anywhere else, apart from our own pilot study, where decreasing values of trunk imbalance were associated with pain decrease in those patients who showed sacroiliac symptoms (Schroder et al., 2009). Dalichau et al. (2005) used an ultra sound topometry device (Zebris®, Isny, Germany) to detect a thoracic erection following three modes of muscle activation exercise programs. Spinal erection was accompanied by trunk muscle peak force increases, adaptations in the performance of the Matthiass-Test (at the end of a 30-second test period) and pain decreases. Dalichau et al. (2005) found high correlation coefficients, but not directly between spine shape and peak force or pain changes. They correlated the degree of deviation of the thoracic kyphosis angle at the end of the Matthiass-Test with back pain intensity (r=0,91) and functional deficits (r=0,89). So, the results of Mannion and collaborates (2001b; 2001c), mentioned above, might serve as the only reference remaining for directly calculated correlations in a longitudinal study between peak force increases and pain decreases (r=0,20; p=0,60), but not taking into account exercise induced spine shape alterations.

Additional applications of spine shape analysis

Although the majority of all low back pain cases are of unknown etiology, new diagnosis procedures, such as video raster stereography, might be able to find structural or functional correlates of some specific origin for back pain complaints (McGill, 2007, p. 5).

For example, video raster stereography (Formetric®-system) is able to detect local changes of the convexity of the spinal curvature 6. A sensitivity study of n=21 volunteers suffering from accidental vertebral blockades provided the idea of automatically detectable structural deviations in the alignment of spinous processes in terms of overreaching the midline in the curve of the second mathematical differentiation of the lateral projection of the spine (fig. 6).

Lateral projection of spinal alignment (left) with back surface (drawn green line) and calculated line of vertebral centres (dotted green line) with a focus on the thoracic spine (blue dotted oval) and the second mathematical differentiation (right) with the curve of local changes of angles at a given point (drawn red line) with an emphasis on curve areas reaching or overreaching the midline (red dotted ovals) indicating structural deviations in the normal spinal alignment of the thoracic spine (area above the black dotted line).

Fig. 6. Lateral projection of spinal alignment (left) with back surface (drawn green line) and calculated line of vertebral centres (dotted green line) with a focus on the thoracic spine (blue dotted oval) and the second mathematical differentiation (right) with the curve of local changes of angles at a given point (drawn red line) with an emphasis on curve areas reaching or overreaching the midline (red dotted ovals) indicating structural deviations in the normal spinal alignment of the thoracic spine (area above the black dotted line).

But video raster stereographic signals indicated signs for a vertebral blockade much more often than a manual examination by an expert did. Sensitivity of video raster stereography was almost poor (23%) (Schroder, Farber & Mattes, 2009; Schroder, Stiller & Mattes, 2011).

Furthermore, there was some evidence for the possibility to get helpful additional diagnostic information to identify sacroiliac joint (SIJ) pain origins in patients with single localized low back pain. Problems concerning the sacroiliac joints are supposed to be the cause for about 20% of all low back complaints, but diagnosis is difficult (Foley & Buschbacher, 2006). In a cross-sectional study, women with single localized low back pain corresponding to the area of sacroiliac joints (n=23) showed significantly higher values for trunk imbalance (mean-diff.: 4,9 mm; p<0,001), for pelvis tilt (mean-diff.: 2,8 mm; p=0,007) and for pelvis torsion (mean-diff.: 1,1°; p=0,014) than pain free women (n=89). This was indicating deviations in the frontal plane like in low back pain patients, but enhancing the role of exceeded pelvis parameters. Maybe due to the normal differences between shape and geometry of male and female pelvis anatomy, these sacroiliac signs could not be confirmed statistically for male patients with comparable single localized pain (Schroder, Stiller & Mattes, 2011).

In the field of specific low back complaints, we could identify signals in the spinal alignment of the lumbar lordosis that referred to structural abberations of specific vertebral segments in low back pain patients suffering from a facet joint syndrome (fig. 7) (Schroder, Strubing & Mattes, 2010).

Spinal alignment of three low back pain patients with different types of spine shape suffering from lumbar facet syndrome in repeated measurements (back surface [drawn] and calculated vertebral centres [dotted] before [red] and after [blue] treatment) with signals for structural changes of vertebral elements [arrows]

Fig. 7. Spinal alignment of three low back pain patients with different types of spine shape suffering from lumbar facet syndrome in repeated measurements (back surface [drawn] and calculated vertebral centres [dotted] before [red] and after [blue] treatment) with signals for structural changes of vertebral elements [arrows]

A functional diagnosis procedure to quantify leg length differences and to try out the best fitting correction had been evaluated earlier (Drerup et al., 2001). A functional test protocol for the quantification of spinal flexibility – especially for back extension limitations – by means of video raster stereography is currently performed (fig. 8), as the evidence of lumbar hypermobility or flexibility deficits is well known as a cause or a symptom of low back pain.

With regard to technical limitations of the high resolution Formetric®-system – anticipation of problems dealing with an automatic recognition of the vertebra prominens without manually fixed extra markers, while the upper body was hyperextended maximally and the camera was looking at it from above – the test protocol had to include three test positions. Data acquisition had been performed in a normal position, serving as a native reference to qualify the individual’s spinal alignment. But pictures had also to be taken in a position with a forced hyper kyphosis as a basic reference for the following test position with the same artificial hyper kyphosis performed in a maximally extended spine position (fig. 8). Spinal flexibility for the backward hyperextension could be quantified in terms of changes of the lumbar lordosis angle, which was not affected by the artificial hyper kyphosis test position.

Test position with artificial hyper kyphosis in a basic (left) and a maximally hyper-extended position (middle) and the video raster stereographic representation of spinal mobility (right) for the back extension task

Fig. 8. Test position with artificial hyper kyphosis in a basic (left) and a maximally hyper-extended position (middle) and the video raster stereographic representation of spinal mobility (right) for the back extension task


A single cross-sectional study does not allow to draw any conclusions, whether spine shape alterations are the cause of low back pain or the symptoms following a process of deconditioning. But exercise induced adaptations of spinal alignment suggest the assumption that there is the possibility for a correction of mal-alignment. These alterations should be considered to be due to a functional restoration, comparable to increases of trunk muscle peak forces observed in the process of reconditioning.

Finally, the role of video raster stereography for quality management should be emphasized. The indirect and non-invasive assessment of the spinal curvature and pelvis position parameters offered valid, reliable and helpful information throughout the screening and monitoring processes for out-patient low back pain rehabilitation.

Further investigations, if possible with clustered samples of the degree of chronification or personal strategies of behavioral coping and – if possible – distinguished specific back pain complaints, are necessary to learn more about the role of spinal mal-alignment in patients with low back pain, and probably more about specific effects of different exercise treatment modes.

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