[Functional rasterstereographic images. A new method for biomechanical analysis of skeletal geometry]

Scoliosis and Lower Limb Inequality: To Lift or Not to Lift, That Is the Question

In subjects with scoliotic alterations of the spine, asymmetrical lengths of the lower limbs are frequently observed, a condition commonly referred to as leg length inequality (LLI) or discrepancy (LLD). This asymmetry can induce pelvic misalignments, manifested by an asymmetric height of the iliac crests, and consequently an alteration of the spine's axis. Although correcting this discrepancy might appear to be a straightforward solution, further investigation may reveal other indications. The purpose of this article is to aid clinicians confronted with the decision of whether to compensate for an LLI in individuals with scoliosis, encompassing both adolescents and adults. It presents a literature review on the incidence of LLIs in the general population, distinguishing between structural LLI (sLLI) and functional LLI (fLLI) types of LLIs, and quantifying their magnitude with clinical and instrumental evaluation. Additionally, it links these two types of LLIs to the type of scoliosis (structural or functional). From a clinical perspective, it also examines the compensatory mechanisms employed by the pelvis in the presence of structural or functional LLIs in order to draw useful indications for therapeutic decisions. Moreover, it proposes an additional evaluation parameter in the coronal plane, namely the central sacral vertical line (CSVL), to aid in the decision-making process regarding LLI compensation. Although this parameter has been documented in the literature, it has been little associated with LLIs. The findings indicate that scoliotic discrepancies should be compensated (conservatively or surgically) only when the imbalance of the femoral heads is on the same side as the imbalance of the sacrum and the iliac crests; this corrective action should result in a reduction of the overhang in the coronal plane.

Immediate Effect of Simulated High Heels on Pelvic and Spinal Posture in Healthy Young Subjects: A Cross-Sectional Study

Background Investigations regarding the role of high-heeled shoes in the alteration of the spinopelvic profile attempted to identify a correlation with pain in the lower back. Conclusions from these studies, however, are controversial. In authors knowledge no studies were carried out to investigate the effect of heels on male population, which has been overlooked due to gender-related customs. Research question What is the immediate effect of the height of heels on the sagittal back profile (trunk inclination (TI), pelvic inclination, lordotic lumbar angle (ITL-ILS), kyphotic dorsal angle, lumbar arrow, and cervical arrow) in females and males, not used to wearing high-heeled shoes? Methods One hundred healthy young adult subjects were enrolled. Three were excluded. The remaining 97 subjects (48 female and 49 male) underwent a three-dimensional analysis of the posterior surface of the trunk, using rasterstereography. The spinopelvic profile in the barefoot condition, and with the heel raised by 3 and 7 cm, was recorded. To evaluate the reproducibility of the measure, the neutral evaluation was repeated twice in 23 subjects (13 males, 10 females). Results The change of heel height did not show statistically significant differences for any of the variables used; instead, significant differences were found stratifying the results according to the sex of the subjects tested. Test-retest evaluation in the neutral condition showed no significant differences using the Student's t-test (p > 0.05). Repeatability was excellent and significant for all data used (minimum TI r = 0.85, maximum ITL-ILS r = 0.97). Significance Studying the effect of heels on the spino-pelvic profile also in the male population is crucial for promoting gender-inclusive healthcare, enhancing occupational health practices and developing possible preventive measures. Nevertheless, in the sample of females and males evaluated in this study, the different heights of heel lift did not immediately induce significant changes in pelvis and spine posture. If there is therefore a correlation between low-back pain and the use of heels, it should not reasonably be sought in the immediate change of the spino-pelvic profile caused by raising the heels. However, the variables analyzed differed according to sex.

Differences in upper body posture between patients with lumbar spine syndrome and healthy individuals under the consideration of sex, age and BMI

BACKGROUND

Work-related forced postures, such as prolonged standing work, can lead to complaints in the lower back. Current research suggests that there is increased evidence of associations between patients with low back pain (LBP) and reduced lordosis in the lumbar spine and generally less spinal tilt in the sagittal plane. The aim of this study is to extend the influence of LBP to other parameters of upper body posture in standing, taking into account the rotational and frontal planes.

METHODS

The study included a no-LBP group (418 males, 412 females, aged 21-65 years) and an LBP group (138 subjects: 80 females, 58 males, aged 18-86 years) with medically diagnosed lumbar spine syndrome (LSS). The "ABW BodyMapper" back scanner from ABW GmbH in Germany was used for posture assessment using video raster stereography. Statistical analyses employed two-sample t-tests or Wilcoxon-Mann-Whitney-U tests to assess the relationship between the LBP/no-LBP groups and back posture parameters. Linear and logarithmic regressions were used with independent variables including group, sex, height, weight and body mass index (BMI). Significance level: α = 0.05 (95% confidence).

RESULTS

The regression analysis showed that sagittal parameters of the spine (sagittal trunk decline, thoracic and lumbar bending angle, kyphosis and lordosis angles) depend primarily on sex, age, BMI, height and/or weight but not on group membership (LBP/no-LBP). In the shoulder region, a significant dependency between group membership and scapular rotation was found. In the pelvic region, there were only significant dependencies in the transverse plane, particularly between pelvic torsion and BMI, weight, height and between pelvic rotation and group membership, age and sex.

CONCLUSION

No difference between the patients and healthy controls were found. In addition, sex appears to be the main influencing factor for upper body posture. Other influencing factors such as BMI, height or weight also seem to have a significant influence on upper body posture more frequently than group affiliation.

Forced Straightening of the Back Does Not Improve Body Shape

BACKGROUND

Sitting for a long time causes various postural problems, such as slump sitting. It has been reported that employing a corrected sitting position while lifting the sternum is effective in improving this form of posture. We investigated how a corrected sitting posture with the lifting of the sternum is different from a forced position that is applied through the command and passive positions.

MATERIALS AND METHODS

The postural angle of 270 subjects aged 19-23 years was measured in the passive, forced, and corrected positions using a Saunders inclinometer and a Formetric 4D system.

RESULTS

As a result, the corrected position had a small range (min-max) at all angles, but the forced position and passive position had a large range (min-max). The lumbar lordosis angle in the corrected position showed positive values throughout its range (min-max), while the other groups showed negative values, which indicates the kyphotic position of the lumbar section. In addition, the percentage error in the corrected position was small, but it presented high values in the other groups. When comparing the average angles between the groups, there were substantial changes observed between the corrected position and the other groups. It was found that the corrected position with the sternum lifted, which is applied to improve slump sitting in the clinical environment, exhibited an angle that differed from that of the forced position and the passive position.

CONCLUSIONS

Our results suggest that a forced position on the command "scapular retraction" does not meet the clinical assumptions of posture correction, in contrast to the corrected position with the lifting of the sternum for the improvement of slump sitting. The accurate correction of the position of the sternum and sacrum improves the position of the spine in the sagittal plane, enabling physiological values for the kyphosis and lordosis angle parameters to be obtained. This approach combines the ease of execution and precision of the effect. The fact that this method does not require complex tools to accurately correct the body encourages the implementation of this solution in clinical practice.

Effects of Artificially Induced Leg Length Discrepancy on Treadmill-Based Walking and Running Symmetry in Healthy College Students: A Lab-Based Experimental Study

Leg length discrepancy (LLD) is a common postural deviation of musculoskeletal origin, which causes compensatory reactions and often leads to injury. The aim of the study was to investigate the effect of artificially induced LLD on gait symmetry by means of the spatiotemporal gait parameters and ground reaction forces (GRFs) using a treadmill equipped with capacitive sensors (instrumented) as well as the EMG activity of trunk and hip muscles during walking and running. Twenty-six healthy male and female college students were required to perform two sets of four 2.5-min walking and running trials on an instrumented treadmill at 5.6 and 8.1 km·h-1, respectively, without (0) and with 1, 2, and 3 cm LLD implemented by wearing a special rubber shoe. Statistical analysis was performed using one-way repeated measures or a mixed-design ANOVA. Most spatiotemporal gait parameters and GRFs demonstrated an increase or decrease as LLD increased either on the short-limb or the long-limb side, with changes becoming more apparent at ≥1 cm LLD during walking and ≥2 cm LLD during running. The EMG activity of trunk and hip muscles was not affected by LLD. Our findings showed that gait symmetry in terms of treadmill-based spatiotemporal parameters of gait and GRFs is affected by LLD, the magnitude of which depends on the speed of locomotion.

Influence of Lateral Sitting Wedges on the Rasterstereographically Measured Scoliosis Angle in Patients Aged 10-18 Years with Adolescent Idiopathic Scoliosis

Adolescent idiopathic scoliosis (AIS) is a three-dimensional axial deviation of the spine diagnosed in adolescence. Despite a long daily sitting duration, there are no studies on whether scoliosis can be positively influenced by sitting on a seat wedge. For the prospective study, 99 patients with AIS were measured with the DIERS formetric III 4D average, in a standing position, on a level seat and with three differently inclined seat wedges (3°, 6° and 9°). The rasterstereographic parameters 'scoliosis angle' and 'lateral deviation RMS' were analysed. The side (ipsilateral/contralateral) on which the optimal correcting wedge was located in relation to the lumbar/thoraco-lumbar convexity was investigated. It was found that the greatest possible correction of scoliosis occurred with a clustering in wedges with an elevation on the ipsilateral side of the convexity. This clustering was significantly different from a uniform distribution (p < 0.001; chi-square = 35.697 (scoliosis angle); chi-square = 54.727 (lateral deviation RMS)). It should be taken into account that the effect of lateral seat wedges differs for individual types of scoliosis and degrees of severity. The possibility of having a positive effect on scoliosis while sitting holds great potential, which is worth investigating in follow-up studies.

Reference values and functional descriptions of transverse plane spinal dynamics during gait based on surface topography

Spinal dynamics during gait have been of interest in research for many decades. Based on respective previous investigations, the pelvis is generally expected to be maximally forward rotated on the side of the reference leg at the beginning of each gait cycle and to reach its maximum counterrotation approximately at the end of the reference leg's stance phase. The pelvic-upper-thoracic-spine coordination converges towards an anti-phase movement pattern in high velocities during ambulation. The vertebral bodies around the seventh thoracic vertebra are considered to be an area of transition during human ambulation where no or at least little rotary motion can be observed. The respective cranial and caudal vertebrae meanwhile are expected to rotate conversely around this spinal point of intersection. However, these previous assumptions are based on scarce existing research, whereby only isolated vertebrae have been analyzed contemporaneously. Due to huge methodological differences in data capturing approaches, the results are additionally hardly comparable to each other and involved measurement procedures are often not implementable in clinical routines. Furthermore, none of the above-mentioned methods provided reference data for spinal motion during gait based on an appropriate number of healthy participants. Hence, the aim of this study was to present such reference data for spinal rotary motion of every vertebral body from C7 down to L4 and the pelvis derived from surface topographic back shape analyses in a cohort of 201 healthy participants walking on a treadmill at a given walking speed of 5 km/h. Additionally, the spine's functional movement behavior during gait should be described in the transverse plane based on data derived from this noninvasive, clinically suitable measurement approach and, in conclusion, the results shall be compared against those of previous research findings derived from other measurement techniques. Contrary to the previous functional understanding, the area of the mid-thoracic spine was found to demonstrate the largest amplitude of rotary motion of all investigated vertebrae and revealed an approximately counterrotated movement behavior compared to the rotary motion of the pelvis. In both directions, spinal rotation during gait seemed to be initiated by the pelvis. The overlying vertebrae followed in succession in the sense of an ongoing movement. Therefore, the point of intersection was not statically located in a specific anatomical section of the spine. Instead, it was found to be dynamic, ascending from one vertebra to the next from caudal to cranial in dependence of the pelvis's rotation initiation.

Reference Values for 3D Spinal Posture Based on Videorasterstereographic Analyses of Healthy Adults

Visual examinations are commonly used to analyze spinal posture. Even though they are simple and fast, their interrater reliability is poor. Suitable alternatives should be objective, non-invasive, valid and reliable. Videorasterstereography (VRS) is a corresponding method that is increasingly becoming established. However, there is a lack of reference data based on adequate numbers of participants and structured subgroup analyses according to sex and age. We used VRS to capture the spinal posture of 201 healthy participants (aged 18-70 years) divided into three age cohorts. Three-dimensional reference data are presented for the global spine parameters and for every vertebral body individually (C7-L4) (here called the specific spine parameters). The vertebral column was found to be systematically asymmetric in the transverse and the coronal planes. Graphical presentations of the vertebral body posture revealed systematic differences between the subgroups; however, large standard deviations meant that these differences were not significant. In contrast, several global parameters (e.g., thoracic kyphosis and lumbar lordosis) indicated differences between the analyzed subgroups. The findings confirm the importance of presenting reference data not only according to sex but also according to age in order to map physiological posture changes over the life span. The question also arises as to whether therapeutic approximations to an almost symmetrical spine are biomechanically desirable.

Acute Effects of Self-Correction on Spine Deviation and Balance in Adolescent Girls with Idiopathic Scoliosis

Background: Adolescent idiopathic scoliosis (AIS) is a three-dimensional deformity of spine and trunk with a higher incidence in girls. AIS alters and reduces postural control and balance. Self-correction movement (SCM) is a well-known non-invasive approach to ameliorate spine curve in AIS subjects. We aimed to evaluate the effects of SCM on the spine and on the balance of adolescents with AIS with a new non-invasive instrumentation. Methods: A total of 38 girls with AIS were recruited. To evaluate the acute effects of SCM and the oscillations of center of pressure (COP), we used LiDAR technology combined with a stabilometric platform to evaluate both changes in spinal curves and balance at the same time. Two tests were carried out simultaneously using the two instruments: before the execution of SCM, in the spontaneously assumed position of each subject (SP) and after the execution of SCM, during the achieved position (SC). Sway area, COP medio-lateral and antero-posterior directions, eccentricity of the ellipse and vertebral lateral deviation were recorded. The two conditions were compared with a Wilcoxon signed-rank test. Results: In general, all measures showed lower values in SC condition (p < 0.05), except the variation along the Y axis. Conclusions: Thanks to objective measured data, the therapists observed real-time changes during the performance of SCM, appreciating its efficacy on curve correction.

Influence of Footwear on Posture and Comfort in Elite Rugby Players

Influence of footwear on posture in athletes is poorly documented despite its potential impact on biomechanics and injury risk. The aim of this study was to investigate effects of different footwear geometries on comfort and posture on a cohort of 48 elite rugby players. Spine posture was characterized by photogrammetry, while center of pressure was measured by means of a force platform. Three different footwear outsoles architectures (one rugby shoe with flat outsole, one rugby shoe with a 10 mm heel rise and foot arch support, and a running shoe with a 10mm heel rise and foot arch support) were compared to non-shod in randomized order. Then comfort felt at the level of foot and spine was also estimated by subjective questionnaires. Compared to the flat rugby model, both other models induced significantly (p<0.05) greater comfort at the level of foot and spine, a slight shift toward of center of pressure and a spinal posture closer to that observed when non-shod. The footwear geometry influences comfort and posture at the level of the foot as well as spine and should be considered in a dual purpose of injury prevention and performance.

Relationship Between Electromyographic Frequency of the Erector Spinae and Location, Direction, and Number of Spinal Curvatures in Children with Scoliotic Changes

INTRODUCTION

The aim of the study was to assess the relationship between erector spinae electromyographic frequency (SEMG) and the location, direction and number of spinal curvatures in children with scoliotic changes.

METHODS

Analysis comprised 103 (42,21%) children with scoliosis and 141 (57.79%) with scoliotic posture. Body posture and the spine were examined using the Diers formetric III 4D optoelectronic method. Electromyographic analysis was performed using a 14-channel Noraxon TeleMyo DTS apparatus.

RESULTS

In girls, the highest mean SEMG frequency of the erector spinae, calculated from 16 measurements, occurred in the case of scoliotic posture (Mean = 73.69 Hz), while in boys, the greatest values were noted for scoliosis (Mean = 79.75 Hz). There was a significant correlation between erector spinae SEMG frequency and curvature location, both in the scoliosis group (p = 0.003) and in the group with scoliotic posture (p = 0.04). There was also a significant correlation between SEMG frequency of the erector spinae and direction of the curvature, both in the scoliosis (p = 0.01) and scoliotic posture groups (p = 0.04), as well as between the erector spinae SEMG frequency and the number of spinal curvatures (scoliosis group: p = 0.03; scoliotic posture group: p = 0.03).

CONCLUSION

The study is of applicative value and fills the gap in research on erector spinae SEMG frequency of in low-grade scoliosis among small children. Our research can also be used in research on the etiology and progression scoliosis. Visible disturbances in the erector spinae SEMG frequency (activity and tension) contribute to the development of curvature and testify to the fact that these changes are the primary cause of idiopathic scoliosis. Scoliosis is merely a symptom, an external expression of CNS dysfunction that is not fully recognised. It is also visible on the SEMG record of postural muscles. Our objective is to contribute to creating a future model record for SEMG of the postural muscles, characteristic for children with scoliosis. Then, based on electromyographic examination, it will be possible to identify initial symptoms of scoliosis and start preventive rehabilitation before irreversible bone changes occur.

The influence of smartphone use on spinal posture - A laboratory study

BACKGROUND

Smartphones have become increasingly more popular and complicated tasks can be performed with these devices. However, the increasing use is associated with shoulder and neck pain, as well as with psychological addiction.

RESEARCH QUESTION

Do different smartphone tasks lead to changes in spinal posture and pelvic position? Is there a relationship between smartphone addiction and changes in posture?

METHODS

A cross-sectional study including 50 participants was performed. Test subjects completed the Smartphone Addiction Scale and the SF-36 health questionnaire. Subjects spinal posture and pelvic position during different smartphone tasks were measured through a surface topography system. The different tasks were: standing in an upright position, simulating a phone call, texting with one or two hands during standing or while walking on a treadmill. Paired T-tests and ANOVA tests were performed to evaluate differences. The Kendall rank test was used to investigate the association between clinical scores and changes in spinal posture.

RESULTS

All smartphone tasks lead to a significant increase in thoracic kyphosis and trunk inclination during standing and while walking. A significant increased lumbar lordosis was also found. Texting with one or two hands correlated with increased surface rotation. No associations between smartphone addiction and changes of the spinal posture were reported.

SIGNIFICANCE

This represents the first surface topography study that investigated the influence of different smartphone tasks on the spinal posture and pelvic position during standing and while walking. With the results of this study we demonstrated that smartphone use leads to significant changes of sagittal and frontal spine parameters. Further research should focus on the evaluation of possible detrimental effects of long-term smartphone use on the spinal posture and on the development of preventive measures.

Relationship between back posture and early orthodontic treatment in children

Background

The purpose of this study was to analyze the relationship between body posture and sagittal dental overjet in children before and after early orthodontic treatment with removable functional orthodontic appliances.

Methods

Angle Class II patients (mean age 8.2 ± 1.2 years; 29 males and 25 females) with a distinctly enlarged overjet (> 9 mm) were retrospectively examined regarding body posture parameters before and after early orthodontic treatment. In addition, changes in overjet were investigated with the aid of plaster models. Forms of transverse dysgnathism (crossbite, lateral malocclusions) and open bite cases were excluded. Body posture parameters kyphosis, lordosis, surface rotation, pelvic tilt, pelvic torsion and trunk imbalance were analyzed by means of rasterstereographical photogrammetry to determine, if the orthodontic overjet correction is associated with specific changes in posture patterns.

Results

In nearly all patients an overjet correction and an improvement regarding all body posture and back parameters could be noted after early orthodontic treatment. Overjet reduction (− 3.9 mm ± 2.1 mm) and pelvic torsion (− 1.28° ± 0,44°) were significantly (p < 0.05) and moderately correlated (R = 0.338) with no significant associations found for the other posture and back parameters (p > 0.05).

Conclusion

Overjet reduction during early orthodontic treatment may be associated with a detectable effect on pelvic torsion.

Standard reference values of the upper body posture in healthy middle-aged female adults in Germany

In order to classify and analyze the parameters of upper body posture, a baseline in form of standard values is demanded. To this date, standard values have only been published for healthy young women. Data for female adults between 51 and 60 years are lacking. 101 symptom-free female volunteers aged 51–60 (55.16 ± 2.89) years. The mean height of the volunteers was 1.66 ± 0.62 m, with a mean body weight of 69.3 ± 11.88 kg and an average BMI of 25.02 ± 4.55 kg/m². By means of video raster stereography, a 3D-scan of the upper back surface was measured in a habitual standing position. The confidence interval, tolerance range and ICCs were calculated for all parameters. The habitual standing position is almost symmetrical in the frontal plane the most prominent deviation being a slightly more ventral position of the left shoulder blade in comparison to the right. The upper body (spine position) is inclined ventrally with a minor tilt to the left. In the sagittal plane, the kyphosis angle of the thoracic spine is greater than the lordosis angle of the lumbar spine. The pelvis is virtually evenly balanced with deviations from an ideal position falling under the measurement error margin of 1 mm/1°. There were also BMI influenced postural variations in the sagittal plane and shoulder distance. The ICCs are calculated from three repeated measurements and all parameters can be classified as "almost perfect". Deflections from an ideally symmetric spinal alignment in women aged 51–60 years are small-scaled, with a minimal frontal-left inclination and accentuated sigmoidal shape of the spine. Postural parameters presented in this survey allow for comparisons with other studies as well as the evaluation of clinical diagnostics and applications.

Body Posture Defects and Body Composition in School-Age Children

The aim of the study was to assess the relationship between the shape of the anteriorposterior spinal curvature and body composition in schoolchildren. The study included 257 children, aged 11–12. Correct spinal curvature was established in 106 (41.08%) subjects. Other types included: decreased kyphosis and correct lordosis—40 participants (15.50%), correct kyphosis and decreased lordosis—24 individuals (9.30%), increased kyphosis and correct lordosis—17 subjects (6.59%), correct kyphosis and increased lordosis—22 children (8.53%), decreased kyphosis and decreased lordosis—32 people (12.40%), decreased kyphois and increased lordosis—four of the examined subjects (1.55%) increased kyphosis and lordosis—13 people (5.04%). In addition, 134 (51.94%) demonstrated scoliotic posture and eight (3.10%) scoliosis. There were significant relationships between the shape of the anteriorposterior curvatures and body composition in schoolchildren. Those with a strong body build (predominance of mesomorphs) were generally characterised by the correct formation of these curvatures. In contrast, lean subjects (with the predominance of ectomorphic factors) were more likely to experience abnormalities. No correlations with body composition were observed in the group with scoliotic posture or scoliosis. Both in the prevention and correction of postural defects, one should gradually move away from one-sided, usually one-system, therapeutic effects. An approach that takes into account both somatic and neurophysiological factors seems appropriate. With the correct body composition and structure, shaping the habit of correct posture is much easier.

Clinical classification of scoliosis patients using machine learning and markerless 3D surface trunk data

Markerless 3D surface topography for scoliosis diagnosis and brace treatment can avoid repeated radiation known from standard X-ray analysis and possible side effects. Combined with the method of torso asymmetry analysis, curve severity and progression can be evaluated with high reliability. In the current study, a machine learning approach was utilised to classify scoliosis patients based on their trunk surface asymmetry pattern. Frontal X-ray and 3D scanning analysis with a clinical classification based on Cobb angle and spinal curve pattern were performed with 50 patients. Similar as in a previous study, each patient's trunk 3D reconstruction was used for an elastic registration of a reference surface mesh with fixed number of vertices. Subsequently, an asymmetry distance map between original and reflected torso was calculated. A fully connected neural network was then utilised to classify patients regarding their Cobb angle (mild, moderate, severe) and an Augmented Lehnert-Schroth (ALS) classification based on their full torso asymmetry distance map. The results reveal a classification success rate of 90% (SE: 80%, SP: 100%) regarding the curve severity (mild vs moderate-severe) and 50-72% regarding the ALS group. Identifying patient curve severity and treatment group was reasonably possible allowing for a decision support during diagnosis and treatment planning. Graphical abstract.

Dynamic spinal posture and pelvic position analysis using a rasterstereographic device

BACKGROUND

Until recently, rasterstereographic analysis of the spine was limited to static measurements. However, understanding and evaluating the motion of the spine under dynamic conditions is an important factor in the diagnosis and treatment of spinal pathologies. The aim of this study was to study the spinal posture and pelvic position under dynamic conditions and compare it to static measurements using a dynamic rasterstereographic system.

METHODS

A total of 121 healthy volunteers (56 females; 65 males) were included in this observational study. The parameters trunk inclination, trunk imbalance, pelvic obliquity, kyphotic angle, lordotic angle, surface rotation, and lateral deviation were studied and compared under static and dynamic (1, 2, 4, 5 km/h) conditions using the system "Formetric 4D Motion®" (DIERS International GmbH, Germany).

RESULTS

Female volunteers had a higher lordotic angle than males under static conditions (p < 0.001). Trunk inclination (5.31° vs. 6.74°), vertebral kyphotic angle (42.53° vs. 39, 59°), and surface rotation (3.35° vs. 3.81°) increase under dynamic conditions (p < 0.001). Trunk inclination and lordotic angle both show significant changes during walking compared to static conditions (p < 0.001).

CONCLUSION

The spinal posture differs between females and males during standing and during walking. Rasterstereography is a valuable tool for the dynamic evaluation of spinal posture and pelvic position, which can also be used to quantify motion in the spine and therefore it has the potential to improve the understanding and treatment of spinal pathologies.

TRIAL REGISTRATION

Retrospectively registered.

Innovative decision support for scoliosis brace therapy based on statistical modelling of markerless 3D trunk surface data

Recently markerless 3D scanning methods receive an increased interest for therapy planning and brace treatment of patients with scoliosis. This avoids repeated radiation known from standard X-Ray analysis. Several authors introduced the method of asymmetry distance maps in order to classify curve severity and progression. The current work extends this approach by statistical mean shape 3D models of the human trunk in order to classify patients. 50 patients were included in this study performing frontal X-ray and 3D scanning analysis. All patients were classified by a clinician according to their Cobb angle and spinal curve pattern (Augmented-Lehnert-Schroth ALS). 3D reconstructions of each patient trunk were processed in a way to elastically register a reference surface mesh with fixed number of data points. Mean 3D shape models were generated for each curve pattern. An asymmetry distance map was then calculated for each patient and mean shape model. Single patient 3D reconstructions were classified according to severity and ALS treatment group. Optimal sensitivity and specificity was 97%/39% thoracic and 87%/42% lumbar respectively for detecting mild and moderate-severe patients. Identifying a treatment group was possible for three combined groups allowing to support decisions during diagnosis and therapy planning.

Comparison of two different designs of forefoot off-loader shoes and their influence on gait and spinal posture

BACKGROUND

The purpose of forefoot off-loader shoes (FOS) is to unload the operated region of the foot in order to allow early mobilization and rehabilitation. However, little is known about the actual biomechanical effects of different designs of FOS on gait, pelvis and spine.

RESEARCH QUESTION

Aim of this study was to analyse and compare the effects of two different designs of forefoot unloader shoes.

METHODS

Ortho-Wedge (FOS A) and Relief-Dual® (FOS B) were evaluated in this study during standing and while walking. Changes of the pelvic position and spinal posture were measured with a surface topography system and an instrumented treadmill. Gait phases were detected automatically by a built-in pressure plate.

RESULTS

Both FOS resulted in a significant increase of pelvic obliquity, pelvic torsion, lateral deviation and surface rotation (p < 0.001) while standing. Between both shoe models, pelvic obliquity and lateral deviation (p < 0.05) were significantly different. During walking, both FOS had a significant effect on spine and pelvis (p < 0.05), however only minor differences were found between the designs. All gait parameters were affected more, wearing FOS A than B. Step length were significantly longer by wearing FOS (p < 0.005). However stance phase raised and swing phase is reduced on the leg wearing FOS A (p < 0.001).

SIGNIFICANCE

The study showed that FOS lead to significant changes in pelvic position and spinal posture during standing and while walking. A compensating shoe on the contralateral side is therefore recommend. Gait parameters however were affected more by the traditional FOS A half-shoe. The sole- design and shape of FOS B leads to a more physiological roll-over of the foot.

Dynamic evaluation of simulated leg length inequalities and their effects on the musculoskeletal apparatus

BACKGROUND

Leg length inequalities (LLI) are a common problem in medicine. So far, the diagnosis and treatment are performed under static conditions. Surface Topography (ST) is an optical, non-invasive technique that uses the principle of triangulation to measure spinal posture and pelvic position. This technique offers the opportunity to detect and treat LLIs and their effects under dynamic conditions.

RESEARCH

question The aim of the study is to show that ST can detect simulated LLIs under dynamic conditions and to prove if there are differences between the effects on the human body under static and dynamic conditions.

METHODS

In the clinical study a total of 30 test subjects were examined with a ST measuring device. LLIs (1 to 4 cm) were simulated using a custom- built sandal and insoles of various thickness. The pelvic obliquity, the surface rotation and lateral deviation of the spine were detected on a treadmill under static and dynamic conditions (3 km/h).

RESULTS

Under static and dynamic conditions LLIs lead to a significant increase of all measured parameters. The pelvic obliquity reaches a significant level of p < 0.0001 under static and p = 0.0001-0.0421 under dynamic conditions. However, for all examined parameters the magnitudes of the parameters under dynamic conditions were smaller than under static conditions.

SIGNIFICANCE

The study showed that simulated LLIs also have a significant effect on the human pelvis and spine under dynamic conditions, but with a smaller magnitude than under static conditions. The human individuum is a dynamic one. Because of that, for the future it should be of great interest to use dynamic measurements to detect and treat LLIs to provide an over correction of LLIs.

Spinal posture changes using dynamic rasterstereography during the modified Matthiass test discriminate between postural weak and strong healthy children (10-14 years): a pilot study

The aim of this pilot study was to investigate whether the clinical Matthiass test can be objectified by means of dynamic rasterstereography in children. We aimed at discriminating between postural weak and strong children. Dynamic rasterstereography was used to capture sagittal spinal posture changes during the modified Matthiass test (mMT). Primary outcomes were spinal posture changes (trunk inclination, kyphotic and lordotic angles) during the test. Two-step cluster analysis was run jointly on the three primary outcomes. Data of 101 healthy children (10-14 years, 46% girls) were assessed. Cluster analysis identified two groups of participants with significantly different postural performance levels during the mMT (low vs. high performers). Low performers showed a higher increase in backward lean, as well as kyphosis and lordosis (4°-5°, respectively) when compared to high performers. The two performance groups were age-, BMI-, and activity-matched.Conclusion: This pilot study established preliminary normative data on spinal posture changes during the Matthiass test (high performers) and provided corresponding cutoff values for postural weakness (low performers). These results could provide a basis for future longitudinal and interventional studies targeting long-term consequences of childhood postural weakness and the prevention of back pain. What is Known: • The prevalence of postural insufficiencies in children is high. • No consensus exists about the postural assessment in children. • A common clinical test to identify postural insufficiency is the Matthiass test yet criticized for its subjective assessment. What is New: • This pilot study objectified the modified Matthiass test by rasterstereography and statistically identified two groups of healthy children with different postural performance levels. • It established preliminary normative data on spinal posture changes and provided corresponding cutoff values for postural weakness.

Three dimensional analysis of spino-pelvic alignment in individuals with acutely herniated lumbar intervertebral disc

BACKGROUND

Lumbar intervertebral disc herniation affects a large number of patients annually and are the most common cause of sciatica.

OBJECTIVES

This study was aimed at measuring the spino-pelvic alignment and its relation to the functional limitations in subjects with acutely herniated lumbar disc.

METHODS

Sixteen patients with acute Lumbar Disc Herniation (LDH group) and 16 healthy matched volunteers (healthy group) represented the sample of the study. The patients were recently diagnosed as lumbar disc herniation (L4-5 or L5-S1) with acute sciatica and antalgic posture using magnetic resonance imaging. Spino-pelvic alignment was measured via Rasterstereography. Functional disability among patients was assessed using Oswestry Disability Index Arabic version.

RESULTS

Trunk inclination, trunk imbalance, pelvic obliquity, pelvic torsion, lordotic and scoliotic angles were significantly different between groups (P ≤ 0.05). A non-significant difference in kyphotic angle was found between the patients and healthy controls. There was no association between the measured postural changes and functional disabilities in patients with lumbar disc herniation (P ≤ 0.05).

CONCLUSION

There are significant postural changes in patients with acutely herniated lumbar disc which has no relation to functional disability. These results support the concept of staying active during acute stage.

Appraisal of the DIERS method for calculating postural measurements: an observational study

Background

Surface topography is increasingly used with postural analysis. One system, DIERS formetric 4D, measures 40 defined spine shape parameters from a 6-s scan. Through system algorithms, a set of spine shape parameter values from 1 of 12 recorded images obtained during a scan becomes the DIERS-reported value (DRV) for postural assessment. The purpose of the current study was to compare DRV with a standard average value (SAV) calculated from all 12 images to determine which method is more appropriate for assessing postural change.

Methods

One mannequin and 30 human participants were scanned over 5 days. Values from each image and the DRV for 40 defined spine shape parameters were exported, and mean DRV, mean SAV, mean DRV, and within-scan variance were calculated. Absolute difference and percent change between mean DRV and mean SAV were calculated for the mannequin and humans. Inter-method reliability was calculated for humans. Within-scan variance for each parameter was tested for significant variability.

Results

For all spine shape parameters on the mannequin, absolute difference (< 0.6 mm, 0.1°, or 0.1%) and percent change (< 2.90%) between mean DRV and mean SAV for each parameter were small. Nine parameters on human participants had a large percent change (> 7%). Absolute difference between mean DRV and mean SAV for those nine parameters was small (≤ 0.87 mm or 0.61°). Absolute difference for all other parameters ranged from 0.02 to 6.98 mm for distance measurements, from 0.01 to 1.21° for angle measurements, and from 0.15 to 0.22% for percentage measurements. Inter-method reliability between DRV and SAV was excellent (0.94–1.00). For the mannequin, within-scan variance was small (< 1.62) for all parameters. For humans, within-scan variance ranged from 0.05 to 36.04 and was different from zero for all parameters (all P < 0.001).

Conclusions

The minimal variability observed in the mannequin suggested the DIERS formetric 4D instrument had high within-scan reliability. The DRV and SAV provided comparable spine shape parameter values. Because within-scan variability is not reported with the DRV, the clinical usefulness of current DRV values is limited. Establishing an estimate of variance with the SAV will allow clinicians to better identify a clinically meaningful change.

Influence of proprioceptive insoles on spinal curvature in patients with slight idiopathic scoliosis

PURPOSE

Proprioceptive insoles are known to influence the functions of posture and gait by modulations of the sensory structures at the sole of the foot. Literature has shown that they could improve the position of the upper-body in patients with postural complaints of the musculoskeletal system. The aim of this study was to evaluate the influence of proprioceptive insoles on the spinal curvature in patients with slight idiopathic scoliosis.

PATIENTS AND METHODS

Eighteen patients were included in this prospective, single-centre, randomized study. All patients needed to have a relevant growth potential and suffered from a slight idiopathic scoliosis. Two groups were used, where group 1 performed physiotherapy twice a week, whereas group 2 was additionally supplied with proprioceptive insoles. Patients underwent three-dimensional rasterstereography for back-shape analysis. Furthermore, a conventional x-ray imaging of the spine was performed at the beginning and 1 year later to document the curvatures.

RESULTS

There was no statistical difference in the Cobb angles, and in almost all parameters of the rasterstereography, there was no statistically significant change between and within both groups.

CONCLUSION

According to the results of this study, there was no evidence of any statistical significant effect of proprioceptive insoles on spinal curvature in patients with slight idiopathic scoliosis.

The correlation between radiographic and surface topography assessments in three plane pelvic parameters

BACKGROUND

Noninvasive rasterstereography has been reported as a helpful tool for assessing pelvic parameters. However, the validation and reproducibility of this tool are still questionable.

OBJECTIVE

To investigate the correlation between video rasterstereography device (VRD) and X-ray photography in terms of validity and reproducibility (inter- and intra-examiner reliability) in pelvic parameters.

METHODS

Thirty male and female healthy subjects with a mean age (26.9 ± 4.9 years) participated in this study. Subjects were examined by VRD for three pelvic parameters (pelvic torsion, pelvic tilt, and pelvic inclination). Measurements were conducted by three different examiners. Subjects were examined by X-ray radiography for the same pelvic parameters as well. Pearson correlation coefficient (r) was used to examine the validity and Intra-class correlation coefficient (ICC) was used to check intra- and inter-examiner reliability.

RESULTS

For pelvic torsion, tilt, and inclination the validity levels of VRD were 0.867, 0.996, and 0.930 (P < 0.05), respectively; while the intra- and inter-examiner reliability coefficients were 0.999, 0.999, and 0.998 and 0.990, 0.997, and 0.989, respectively.

CONCLUSION

The results of this study revealed that the VRD has both high validity and reliability in assessing the selected three pelvic parameters that reflect the three fundamental planes of movement in healthy subjects. Further studies using VRD are recommended to assess low back pain-associated pelvic parameters.

[Conservative treatment of idiopathic scoliosis : Influence of archetypical Cheneau-Corsets on trunk asymmetry]

BACKGROUND

The vertical posture of the growing child requires minute central nervous control mechanisms to maintain the symmetry of the torso in its various activities. Measuring only static parameters such as the Cobb angle does not describe the dynamic changes of scoliotic deformities in gait. A constant deviation in the frontal, transverse, and sagittal planes from the dynamic symmetry of the trunk is described in motion analysis and the surface changes of the spinopelvic complex.

METHODS

Early intervention with effective bracing, physiotherapy and sport can reverse curve progression in growth spurts, once these are identified by screening. Modern braces have a derotating and reducing effect ("mirror effect") on asymmetric body volumes, thus influencing the growing torso and restoring lasting symmetry. These braces can be reduced for archetypical designs. Latest data support the use of braces to reverse progressing scoliosis.

Effects on posture by different neuromuscular afferent stimulations and proprioceptive insoles: Rasterstereographic evaluation

BACKGROUND

Proprioceptive neuromuscular stimulating insoles are increasingly applied in treating functional complaints, chronic pain, foot disorders and so on.

OBJECTIVES

To evaluate rasterstereography as a tool in objectifying postural changes resulting from neuromuscular afferent stimulation and proprioceptive neuromuscular stimulating insoles and to compare the respective effects on posture.

STUDY DESIGN

This is a prospective experimental study.

METHODS

A total of 27 healthy volunteers were consecutively exposed to six different varying intense neuromuscular afferent stimulating test conditions at three different times. One test condition featured proprioceptive neuromuscular stimulating insoles. In each test condition, a sequence of 12 rasterstereographic recordings of back shape was documented. Changes between six different test conditions and over time for 14 posture characterising parameters were investigated, for example, trunk inclination, pelvic torsion, lateral deviation of the spine's amplitude or sagittal spinal curve.

RESULTS

Standard deviation of our rasterstereographic measurements (±2.67 mm) was better than in most comparable reference values. Different neuromuscular stimuli were found to provoke significant changes to various posture parameters, including trunk inclination, pelvic torsion and so on ( each p < 0.001, F-tests). Proprioceptive neuromuscular stimulating insoles induced significant changes for parameter lateral deviation of the spine's amplitude (p = 0.03).

CONCLUSION

Neuromuscular afferent stimulation and proprioceptive neuromuscular stimulating insoles induce postural changes, which can be detected reliably by rasterstereography.

CLINICAL RELEVANCE

We demonstrated that rasterstereography - a radiation-free imaging modality - enables visualisation and documentation of subtle postural changes induced by varying intense neuromuscular afferent stimulation and the application of proprioceptive neuromuscular stimulating insoles.

Impact of pregnancy on back pain and body posture in women

[Purpose] The purpose of this single-center investigation was to study the impact of pregnancy on back pain and body posture. [Subjects] The subjects were 26 pregnant females. [Methods] Data were generated with a spine scanner (Diers(®) formetric 4D), trunk strength measurement (Diers(®) myoline), a numeric pain scale (0 to 10), and a biomechanical model. Parameters were compared during each trimester. [Results] The alteration in pain level at rest and lumbar lordosis angle in the females revealed a statistical trend during pregnancy. Spearman's test showed positive correlations between body weight and trunk inclination during the second trimester, and between body weight and the kyphosis angle in the third trimester. The trunk inclination and the kyphosis angle revealed a negative correlation in the third trimester. Based on our analysis, the highest moments and muscle strength must be expended in the third trimester. The actual muscle strength is greatest in the second trimester. [Conclusion] Pain at rest must be given greater attention in pregnant females, and their increasing lumbar kyphosis must be counteracted. Exercising the deep segmental muscles may serve as a preventive measure.

[Surgical treatment of scoliosis in childhood and adolescence: Age group and etiology-related indications and choice of instrumentation]

The indications for a corrective surgical procedure for the complex 3-dimensional deformations of the spine collectively known under the term scoliosis, essentially depend on knowledge of the underlying etiology, the time of initial diagnosis in relation to the growth curve of the child and on considerations about the general operability of the patient. An early onset of scoliosis in childhood under defined diagnostic criteria is usually associated with a fast progression of spinal curvature and requires early surgical intervention during the growth period, while scoliosis in adolescence often allows a delayed surgical intervention until all conservative means have been taken into consideration. Corrective measures in the growing spine require procedures and adjustable hardware which can be adapted to vertebral and thoracic growth and thus anticipate the threat of pulmonary insufficiency due to postural and spinal collapse. Towards the end of puberty when spinal growth slowly comes to an end, corrective spinal fusion procedures are considered in those cases of early and late onset scoliosis, where curvature progression is likely to occur.

Early postural changes in individuals with idiopathic Parkinson's disease

Background and Objectives. Postural changes are frequent and disabling complications of Parkinson's disease (PD). Many contributing factors have been evident either related to disease pathology or to adaptive changes. This study aimed at studying the postural changes in subjects with Parkinson's disease and its relation to duration of illness and disease severity. Methods. Eighteen patients with PD and 18 healthy matched volunteers represented the sample of the study. The patients were at stage 1 or 1.5 according to the Modified Hoehn and Yahr Staging with duration of illness between 18 and 36 months. Three-dimensional analysis of the back surface was conducted to explore the postural changes in the sagittal and frontal planes in both the patients and the healthy subjects. Results. Kyphotic angle, lordotic angle, fleche cervicale, fleche lombaire, scoliotic angle, and associated vertebral rotation and pelvic obliquity were significantly increased in patients with PD compared to the healthy subjects (P ≤ 0.05). There was no association between the measured postural changes and duration of illness as well as the severity of the IPD (P ≤ 0.05). Conclusion. Postural changes start in the early stages of idiopathic PD and they have no relationship to the duration of illness and disease severity.

Rasterstereographic measurement of scoliotic deformity

BACKGROUND

Back surface topography has gained acceptance in recent decades. At the same time, the motivation to use this technique has increased. From the view of the patient, the cosmetic aspect has played and still plays a major role as it provides a comprehensive documentation of cosmetic impairment. From the view of the medical practitioner, the aspect of reducing X-ray exposures in diagnosis and follow-up has been dominant and still prevails. Meanwhile, new aspects have emerged: due to the consequent three-dimensional view of the scoliotic condition, treatment success can be visualized convincingly. Clinical diagnosis is supported by information otherwise not supplied by X-rays, such as when functional examinations and diagnostic tests are recorded.

METHODS

Like rasterstereography, most techniques of actual back surface measurement refer to photogrammetry and the triangulation method. However, with respect to the particular clinical application, a wide spectrum of implementations exists. Applications in a clinic require high accuracy of measurement in a short time and comprehensive analysis providing data to be used to supplement and compare with radiographic data. This is exemplified by rasterstereography; the procedures of surface analysis and localization of landmarks using curvatures and the reconstruction of the spinal midline will be described.

ORTHOPAEDIC RELEVANCE

Based on rasterstereographic analysis, different geometrical measures that characterize the back surface are given and underlying skeletal structures described. Furthermore, in analogy to radiological projection, a 3-D reconstruction of the spinal midline is visualized by a frontal and lateral projection, allowing comparison with pertinent X-rays.

CONCLUSIONS

Surface topography and, in particular, rasterstereography provide reliable and consistent results that may be used to reduce X-ray exposure. Unfortunately, the correlation of shape parameters with the radiological Cobb angle is poor. However, the wealth of additional applications substantially enhances the spectrum of clinical value.

[Conservative treatment of idiopathic scoliosis with effective braces: early response to trunk asymmetry may avoid curvature progress]

Vertical posture of the growing child requires minute central nervous control mechanisms in order to maintain symmetry of the torso in its various activities. Scoliosis describes a constant deviation in the frontal, transverse and sagittal planes from the dynamic symmetry of the trunk. Early intervention with effective bracing, physiotherapy and sports can reverse curve progression during growth spurts, once these are identified in screening. Modern braces have a derotating and reducing effect (mirror effect) on asymmetric body volumes, thus influencing the growing torso and restoring lasting symmetry. Recent data support the use of braces to reverse progressing scoliosis.

Does age affect the response of pelvis and spine to simulated leg length discrepancies? A rasterstereographic pilot study

PURPOSE

The purpose of this study was to investigate age differences in the response of the spine and pelvis to simulated leg length inequalities (LLIs).

METHODS

A total of 107 subjects, separated into three age groups (group 1: 20-39 years, group 2: 40-59 years, group 3: >60 years), were used to evaluate for any age effects in the response to LLIs. LLIs of +10, +20, and +30 mm were simulated with a simulation platform on both sides, and the respective changes of pelvic position (pelvic obliquity, pelvic torsion) and spinal posture (lateral deviation, surface rotation, kyphotic, and lordotic angles) were measured with a rasterstereographic system.

RESULTS

In all three age groups an increase in LLI led to significant changes in the pelvic position as measured by the parameters of pelvic obliquity and torsion. No significant differences in the response of the pelvis to the LLIs were found between the age groups. In all age groups an increase in surface rotation and lateral deviation of the spine with increasing LLIs was found. However, none of these parameters responded significantly different between the three age groups.

CONCLUSIONS

Under static conditions, LLIs lead to significant changes of the pelvic position and spinal posture. Despite all known age-related changes, no significant differences of the measured pelvic and spinal parameters in elderly patients as a response to the simulated LLIs occurred.

Evaluation of a novel spine and surface topography system for dynamic spinal curvature analysis during gait

Introduction

The assessment of spinal deformities with rasterstereography can enhance the understanding, as well as can reduce the number of x-rays needed. However, to date this technique only allows measurements under static conditions. Since it would be of great value to be able to also analyze the spine in dynamic conditions, the present study evaluated a novel rasterstereographic system.

Materials and Methods

A new rasterstereographic device was evaluated in a comparison with the gold standard in motion analysis, the VICON system. After initial testing using 12 flat infrared markers adhered to a solid plate, the two systems were evaluated with the markers adhered onto the backs of 8 test subjects. Four triangles were defined using the markers, and the sides of each triangle were measured under static and dynamic conditions.

Results

On the solid plate, the sides of the 4 triangles were measured with a measuring tape and then by the two optical systems. Rasterstereography showed a high accuracy in marker detection on the solid plate. Under dynamic conditions, with the subjects walking on a treadmill, the rasterstereographically-measured side lengths were compared with the lengths measured by the VICON system as an assessment of marker detection. No significant differences (p>0.05) were found between the systems, differing only 0.07–1.1% for all sides of the four triangles with both systems.

Discussion

A novel rasterstereographic measurement device that allows surface and spine topography under dynamic conditions was assessed. The accuracy of this system was with one millimeter on a solid plate and during dynamic measurements, to the gold standard for motion detection. The advantage of rasterstereography is that it can be used to determine a three-dimensional surface map and also allows the analysis of the underlying spine.

Trunk stabilization with sling training in osteoporosis patients—a randomized clinical trial

Fractures due to osteoporosis are one of the principal causes of functional limitations, chronic pain, and greater morbidity in advanced age. In addition to bone risk factors for osteoporotic fractures include extraosseous causes such as falls or reduced neuromuscular capacity. Muscle and coordination exercises enhance the patients’ abilities in daily life and prevent falls. In view of recent conclusions drawn from competitive sports, which stress the significance of the muscles of the trunk in respect of reducing back pain and optimizing posture, we used sling exercises to determine whether osteoporosis patients benefit from it and whether it is more advantageous than traditional physiotherapy. Fifty patients were randomized into two groups. Group A received traditional physiotherapy, while group B was given sling exercises, in each case twice a week for a period of 3 months. The results of treatment (pre-post) were analyzed in terms of pain levels, mobility, trunk strength, and the shape of the back. After a further 3 months with no specific exercise treatment, we retested all patients in order to draw conclusions about the long-term effects of the two types of exercise. Forty-four patients (88 %) completed the study. Patients were assigned to small groups (a maximum of five patients in each group) and, thus, received individual attention and motivation. Positive training effects were achieved in both groups. Significantly better results as regards improvement of mobility and reduction of falls were registered in the sling exercise group.

Determination of the amount of leg length inequality that alters spinal posture in healthy subjects using rasterstereography

PURPOSE

Leg length inequalities (LLIs) can result in an increased energy consumption, abnormal gait or osteoarthritis of the hip. In a previous study we simulated different LLIs of up to 15 mm and evaluated their effects on the pelvic position and spinal posture. We found a correlation between LLIs and resulting changes of the pelvic position. Despite suggestions in the literature we were not able to detect significant changes of the spinal posture. Therefore, the purpose of this study was to determine the amount of LLI that would in fact alter the spinal posture.

METHODS

The subjects were placed on a simulation platform, whose height could be precisely controlled by the measuring device, to simulate different LLIs of up to 20 mm. For LLIs >20 mm, additional precision-cut wooden blocks were used under one foot. After an adaptation period the resulting changes of the pelvis and spine were measured with a rasterstereographic device.

RESULTS

We found a significant correlation between platform height changes and changes of the pelvic position. The frontal spinal parameters surface rotation and lateral deviation changed significantly when simulating differences greater than 20 mm. No changes of the sagittal spinal curvature were measured, however, a trend to decreasing kyphotic angles was noted.

CONCLUSIONS

Our study has shown for the first time that LLIs >20 mm will lead to significant changes in the spinal posture of healthy test subjects. However, these changes were only found in frontal (surface rotation and lateral flexion) spinal parameters, but not in sagittal parameters. Here for the kyphotic angle only a tendency to decreasing angles was noted. We have also found a significant correlation between different leg lengths and changes of the pelvic position. Further, females and males seem to react in the same way to LLIs.

Spinal posture and pelvic position in three hundred forty-five elementary school children: a rasterstereographic pilot study

Children's posture has been of growing concern due to observations that it seems to be impaired compared to previous generations. So far there is no reference data for spinal posture and pelvic position in healthy children available. Purpose of this pilot study was to determine rasterstereographic posture values in children during their second growth phase. Three hundred and forty-five pupils were measured with a rasterstereographic device in a neutral standing position with hanging arms. To further analyse for changes in spinal posture during growth, the children were divided into 12-month age clusters. A mean kyphotic angle of 47.1°±7.5 and a mean lordotic angle of 42.1°±9.9 were measured. Trunk imbalance in girls (5.85 mm±0.74) and boys (7.48 mm± 0.83) varied only little between the age groups, with boys showing slightly higher values than girls. The trunk inclination did not show any significant differences between the age groups in boys or girls. Girls' inclination was 2.53°±1.96 with a tendency to decreasing angles by age, therefore slightly smaller compared to boys (2.98°±2.18). Lateral deviation (4.8 mm) and pelvic position (tilt: 2.75 mm; torsion: 1.53°; inclination: 19.8°±19.8) were comparable for all age groups and genders. This study provides the first systematic rasterstereographic analysis of spinal posture in children between 6 and 11 years. With the method of rasterstereography a reliable three-dimensional analysis of spinal posture and pelvic position is possible. Spinal posture and pelvic position does not change significantly with increasing age in this collective of children during the second growth phase.

Spine deviations and orthodontic treatment of asymmetric malocclusions in children

Background

The aim of this randomized clinical trial was to assess the effect of early orthodontic treatment for unilateral posterior cross bite in the late deciduous and early mixed dentition using orthopedic parameters.

Methods

Early orthodontic treatment was performed by initial maxillary expansion and subsequent activator therapy (Münster treatment concept). The patient sample was initially comprised of 80 patients with unilateral posterior cross bite (mean age 7.3 years, SD 2.1 years). After randomization, 77 children attended the initial examination appointment (therapy = 37, control = 40); 31 children in the therapy group and 35 children in the control group were monitored at the follow-up examination (T2). The mean interval between T1 and T2 was 1.1 years (SD 0.2 years). Rasterstereography was used for back shape analysis at T1 and T2. Using the profile, the kyphotic and lordotic angle, the surface rotation, the lateral deviation, pelvic tilt and pelvic torsion, statistical differences at T1 and T2 between the therapy and control groups were calculated (t-test).

Our working hypothesis was, that early orthodontic treatment can induce negative therapeutic changes in body posture through thoracic and lumbar position changes in preadolescents with uniltaral cross bite.

Results

No clinically relevant differences between the control and the therapy groups at T1 and T2 were found for the parameters of kyphotic and lordotic angle, the surface rotation, lateral deviation, pelvic tilt, and pelvic torsion.

Conclusions

Our working hypothesis was tested to be not correct (within the limitations of this study). This randomized clinical trial demonstrates that in a juvenile population with unilateral posterior cross bite the selected early orthodontic treatment protocol does not affect negatively the postural parameters.

Trial registration

DRKS00003497 on DRKS

Comparative evaluation of a novel measurement tool to assess lumbar spine posture and range of motion

PURPOSE

The diagnosis of low back pain pathology is generally based upon invasive image-based assessment of structural pathology, but is limited in methods to evaluate function. The accurate and robust measurement of dynamic function may assist in the diagnosis and monitoring of therapy success. Epionics SPINE is an advanced strain-gauge measurement technology, based on the two sensor strips SpineDMS system, which allows the non-invasive assessment of lumbar and thoraco-lumbar motion for periods of up to 24 h. The aim of this study was to examine the reliability of Epionics SPINE and to collect and compare normative data for the characterisation of spinal motion in healthy subjects. Furthermore, the identification of parameters that influence lumbar range of motion (RoM) was targeted.

METHODS

Spinal shape was measured using Epionics SPINE in 30 asymptomatic volunteers during upright standing, as well as maximum flexion and extension, to check intra-rater reliability. Furthermore, back shape was assessed throughout repeated maximum flexion and extension movements in 429 asymptomatic volunteers in order to collect normative data of the lordosis angle and RoM in different gender and age classes.

RESULTS

The lordosis angle during standing in the healthy collective measured with Epionics SPINE was 32.4° ± 9.7°. Relative to this standing position, the average maximum flexion angle was 50.8° ± 10.9° and the average extension angle 25.0° ± 11.5°. Comparisons with X-ray and Spinal Mouse data demonstrated good agreement in static positions. Age played a larger role than gender in influencing lumbar posture and RoM.

CONCLUSIONS

The Epionics SPINE system allows the practical and reliable dynamic assessment of lumbar spine shape and RoM, and may therefore provide a clinical solution for the evaluation of lower back pain as well as therapy monitoring.

Test-retest reliability of 3D ultrasound measurements of the thoracic spine

OBJECTIVE

To explore the reliability of the Zebris CMS 20 ultrasound analysis system with pointer application for measuring end-range flexion, end-range extension, and neutral kyphosis angle of the thoracic spine.

SETTING

The study was performed within the School of Physiotherapy in cooperation with the Orthopedic Department at a University Hospital.

PARTICIPANTS

The thoracic spines of 28 healthy subjects were measured.

METHODS

Measurements for neutral kyphosis angle, end-range flexion, and end-range extension were taken once at each time point. The bone landmarks were palpated by one examiner and marked with a pointer containing 2 transmitters using a frequency of 40 kHz. A third transmitter was fixed to the pelvis, and 3 microphones were used as receiver. The real angle was calculated by the software. Bland-Altman plots with 95% limits of agreement, intraclass correlations (ICC), standard deviations of mean measurements, and standard error of measurements were used for statistical analyses. The test-retest reliability in this study was measured within a 24-hour interval.

MAIN OUTCOME MEASUREMENTS

Statistical parameters were used to judge reliability.

RESULTS

The mean kyphosis angle was 44.8° with a standard deviation of 17.3° at the first measurement and a mean of 45.8° with a standard deviation of 16.2° the following day. The ICC was high at 0.95 for the neutral kyphosis angle, and the Bland-Altman 95% limits of agreement were within clinical acceptable margins. The ICC was 0.71 for end-range flexion and 0.34 for end-range extension, whereas the Bland-Altman 95% limits of agreement were wider than with the static measurement of kyphosis. Compared with static measurements, the analysis of motion with 3-dimensional ultrasound showed an increased standard deviation for test-retest measurements.

CONCLUSIONS

The test-retest reliability of ultrasound measuring of the neutral kyphosis angle of the thoracic spine was demonstrated within 24 hours. Bland-Altman 95% limits of agreement and the standard deviation of differences did not appear to be clinically acceptable for measuring flexion and extension.

The effect of simulating leg length inequality on spinal posture and pelvic position: a dynamic rasterstereographic analysis

INTRODUCTION

Leg length inequalities (LLI) are a common finding. Rasterstereography offers a non-invasive, contact-free and reliable method to detect the effects of LLIs on spinal posture and pelvic position.

MATERIALS AND METHODS

A total of 115 subjects were rasterstereographically examined during different artificially created leg length inequalities (5-15 mm) using a platform. The pelvic obliquity and torsion and the lateral and frontal deviation of the spine, as well as the surface rotation, were measured.

RESULTS

Changes in platform height led to an increase of the pelvic tilt and torsion. Only minor changes in the spinal posture were found by different simulated leg length inequalities.

CONCLUSIONS

Our study showed that there was a correlation between an artificial leg length inequality up to 15 mm and pelvic tilt or torsion, but only minor changes in the spinal posture were measured. Further studies should investigate the effects of greater leg length inequalities on spine and pelvis.

Reliability and validity of 4D rasterstereography under dynamic conditions

Purpose of this study was to evaluate the reliability and validity of 4D rasterstereography under dynamic conditions. Therefore simulated anatomical fixed points on a wooden plate were measured during different movements. Seven different motion patterns in all three angles of space were evaluated. The simulated parameter trunk length was measured with an accuracy of 3.58 mm (SD±3.29 mm) and the dimple distance was detected with an accuracy of 0.88 mm (SD±1.04 mm). With this rasterstereographic prototype it is possible to examine dynamically the spinal posture with adequate accuracy.