Axial rotation is regarded as an essential movement of the trunk that allows many individuals to participate in vocations, sports and activities of daily living. Unfortunately when the destabilising nature of rotation is combined with that of spinal flexion, the risk of injuring the spine can increase significantly. Few studies have investigated the potential benefits that maximizing trunk rotation has in certain vocation and sport-related arenas and none have looked at whether adopting certain spinal postures in the sagittal plane can maximise trunk rotation more than others. The aim of the study was to determine the effects of alterations of trunk inclination, spinal posture, pelvic fixation and turning direction on the active range of motion (ROM) of trunk rotation. Twenty healthy individuals participated in the main study. Retro-reflective markers were placed on key anatomical locations and used to track the movement of the thorax and pelvis during a series of repeated maximal trunk rotations in ten different spinal positions within the sagittal plane. Trunk kinematics and kinetics were recorded simultaneously using an optoelectronic motion analysis and force platform measuring system. A repeated-measures multiple analysis of variance (MANOVA) was used to test for the main effects of trunk inclination, spinal posture, fixation of pelvis and direction of turn on maximum active ROM of trunk rotation, maximum pelvic rotation and the anterior-posterior and lateral displacement of the centre of pressure (COP). To investigate test-retest reliability, ten participants were tested on two separate days. Repeatability for each outcome measure was investigated using interclass correlation coefficients (ICC) and Bland Altman graphs. The majority of subjects showed reasonable test-retest reliability for trunk rotation measures in each of the test positions, with ICC’s ranging between 0.562 – 0.731. Overall, trunk inclination (0°, 22.5°, 45°) forward in the sagittal plane had a significant effect on trunk and pelvic rotation (p<0.001) and lateral displacement of the COP (p<0.005) during trunk rotation. As trunk inclination increased from 0° to 45° there was an average increase in trunk rotation ROM of approximately 10 % (approximately 3.4°). Furthermore, increasing trunk inclination led to an increase in lateral displacement of the COP and a decrease in pelvic rotation. Spinal posture (neutral, flexed, extended) at a forward inclination of 45° had a significant effect on trunk rotation (p<0.01) and pelvic rotation (p<0.05), with a neutral spine averaging approximately 3 % (approximately 1.1°) more trunk rotation than a flexed or extended posture. The position and posture of the spine in the sagittal plane appears to have a significant influence on ranges of trunk rotation. The study suggests that rotating the trunk when adopting a neutral spine inclined to 45° will maximise range of trunk rotation and encourage a natural stabilisation of the lower body. This posture meets the unique set of biomechanical requirements for the sport of golf and may help to reduce the risk of injury in manual material handling tasks. Conversely, rotating the trunk whilst the thoracolumbar spine is flexed leads to a reduction in trunk rotation ROM, encourages greater pelvic and lower body rotation, reduces torque production of the trunk and may increase the risk of lower back injury. These findings have important implications in relation to the teaching of spinal position during vocations, sports and activities of daily living that seek to maximise trunk rotation.

Axial rotation is regarded as an essential movement of the trunk that allows many individuals to participate in vocations, sports and activities of daily living. Unfortunately when the destabilising nature of rotation is combined with that of spinal flexion, the risk of injuring the spine can increase significantly. Few studies have investigated the potential benefits that maximizing trunk rotation has in certain vocation and sport-related arenas and none have looked at whether adopting certain spinal postures in the sagittal plane can maximise trunk rotation more than others. The aim of the study was to determine the effects of alterations of trunk inclination, spinal posture, pelvic fixation and turning direction on the active range of motion (ROM) of trunk rotation. Twenty healthy individuals participated in the main study. Retro-reflective markers were placed on key anatomical locations and used to track the movement of the thorax and pelvis during a series of repeated maximal trunk rotations in ten different spinal positions within the sagittal plane. Trunk kinematics and kinetics were recorded simultaneously using an optoelectronic motion analysis and force platform measuring system. A repeated-measures multiple analysis of variance (MANOVA) was used to test for the main effects of trunk inclination, spinal posture, fixation of pelvis and direction of turn on maximum active ROM of trunk rotation, maximum pelvic rotation and the anterior-posterior and lateral displacement of the centre of pressure (COP). To investigate test-retest reliability, ten participants were tested on two separate days. Repeatability for each outcome measure was investigated using interclass correlation coefficients (ICC) and Bland Altman graphs. The majority of subjects showed reasonable test-retest reliability for trunk rotation measures in each of the test positions, with ICC’s ranging between 0.562 – 0.731. Overall, trunk inclination (0°, 22.5°, 45°) forward in the sagittal plane had a significant effect on trunk and pelvic rotation (p<0.001) and lateral displacement of the COP (p<0.005) during trunk rotation. As trunk inclination increased from 0° to 45° there was an average increase in trunk rotation ROM of approximately 10 % (approximately 3.4°). Furthermore, increasing trunk inclination led to an increase in lateral displacement of the COP and a decrease in pelvic rotation. Spinal posture (neutral, flexed, extended) at a forward inclination of 45° had a significant effect on trunk rotation (p<0.01) and pelvic rotation (p<0.05), with a neutral spine averaging approximately 3 % (approximately 1.1°) more trunk rotation than a flexed or extended posture. The position and posture of the spine in the sagittal plane appears to have a significant influence on ranges of trunk rotation. The study suggests that rotating the trunk when adopting a neutral spine inclined to 45° will maximise range of trunk rotation and encourage a natural stabilisation of the lower body. This posture meets the unique set of biomechanical requirements for the sport of golf and may help to reduce the risk of injury in manual material handling tasks. Conversely, rotating the trunk whilst the thoracolumbar spine is flexed leads to a reduction in trunk rotation ROM, encourages greater pelvic and lower body rotation, reduces torque production of the trunk and may increase the risk of lower back injury. These findings have important implications in relation to the teaching of spinal position during vocations, sports and activities of daily living that seek to maximise trunk rotation.

Stenosis is one of the most common causes for spinal surgery. Laminectomy decompression and fusion are surgical procedures prescribed for this condition. The intention of this work was to investigate the effects of a laminectomy decompression, followed by fusion, on a lumbar functional spinal unit (FSU) through in vitro dynamic (±8Nm at 0.125Hz) and quasi-static (±7.5Nm at 0.1Hz) biomechanical tests, for flexion, extension, bending and rotation motions. Six FSUs where disarticulated from four human cadaveric lumbar spines (63 ± 12 years) and were tested under the following sequence: (1) intact, (2) laminectomy decompression, and (3) Pedicle Screw System (PSS), using a load-displacement controlled system. Dynamic neutral zone (NZ), dynamic neutral zone stiffness (NZS) and the range of motion (ROM) were the parameters evaluated. Since only 6 FSUs from different spinal levels were used, any effect related to the spinal level could not be evaluated. This limitation enforced to consider normalized data (with respect to intact) as an alternative analysis, but large standard deviations after transforming the data forced us to contemplate this "a pilot study". Dynamic testing revealed that there were no significant differences in the neutral zone magnitude for any motion after a laminectomy decompression, while its magnitude for flexion-extension was significantly affected by PSS treatment (p<0.004). The change in dynamic NZ (normalized data) was significantly different (p<0.03) after both treatments for flexion-extension motion. The reduction in stiffness (normalized data) for extension after a laminectomy, and the increase in stiffness (normalized data) for flexion and extension after PSS treatment, were both significant (p<0.03 and p<0.05, respectively). The ROM were not statistically significant for the three treatments, but normalized data showed significant differences (p<0.05) for all motions, except for right bending after laminectomy and right rotation after PSS. Non-normalized data from quasi-static testing didn't show any statistically significant difference between the treatments for any motion. Normalized data suggested significant differences for the change in ROM for all motions at multiple load conditions, especially for flexion and extension. This pilot study suggests there may be a considerable effect of a laminectomy on the stability of a lumbar FSU. Dynamic data suggested the changes in neutral zone stiffness triggered by a laminectomy procedure may be significant for extension. PSS treatment increased segment's NZ stiffness by more than double. The changes in ROM from quasi-static loading caused by a laminectomy decompression may be significant as well, especially for flexion (20%) and extension (greater than 10%). It is suggested that further studies involving spine biomechanics should consider and report, but not be limited to the following variables: exposure time of the specimen to room temperature, preservation and testing conditions, ligaments and joints conditions, testing protocol, and loading history.

Bei einer altersgerechten Arbeitsgestaltung mittels digitaler Menschmodelle (DMM) sind die altersbedingten Veränderungen der menschlichen Leistungsfähigkeit zu berücksichtigen. Altersbedingte Veränderungen wie bspw. der Beweglichkeit sind aktuell nur rudimentär bei der virtuellen Arbeitsprozessgestaltung abbildbar. Deshalb wird im Beitrag ein Konzept zur Integration von Altersfaktoren in DMM vorgestellt. Dem User-Centered-Design Prozess folgend, werden die einzelnen Schritte zur Integration von Altersfaktoren am Beispiel der Beweglichkeit dargestellt. Dazu werden die erhobenen Nutzeranforderungen und die Darstellung der nutzerorientierten Konfiguration der Altersfaktoren im DMM dargestellt. Im Ergebnis wird gezeigt, wie altersbedingte Veränderungen der menschlichen Leistungsfähigkeit in DMM nutzer-orientiert eingebunden werden können. Dem Nutzer soll damit perspektivisch eine effektive und effiziente altersgerechte Gestaltung in DMM mittels akkurater, relevanter Daten sowie geeigneter Unterstützung ermöglicht werden.

Bei einer altersgerechten Arbeitsgestaltung mittels digitaler Menschmodelle (DMM) sind die altersbedingten Veränderungen der menschlichen Leistungsfähigkeit zu berücksichtigen. Altersbedingte Veränderungen wie bspw. der Beweglichkeit sind aktuell nur rudimentär bei der virtuellen Arbeitsprozessgestaltung abbildbar. Deshalb wird im Beitrag ein Konzept zur Integration von Altersfaktoren in DMM vorgestellt. Dem User-Centered-Design Prozess folgend, werden die einzelnen Schritte zur Integration von Altersfaktoren am Beispiel der Beweglichkeit dargestellt. Dazu werden die erhobenen Nutzeranforderungen und die Darstellung der nutzerorientierten Konfiguration der Altersfaktoren im DMM dargestellt. Im Ergebnis wird gezeigt, wie altersbedingte Veränderungen der menschlichen Leistungsfähigkeit in DMM nutzer-orientiert eingebunden werden können. Dem Nutzer soll damit perspektivisch eine effektive und effiziente altersgerechte Gestaltung in DMM mittels akkurater, relevanter Daten sowie geeigneter Unterstützung ermöglicht werden.

Leitthema ARBEIT(S).WISSEN.SCHAF(F)T ; Grundlage für Management & Kompetenzentwicklung Mit zunehmendem Alter kommt es zu einer Verringerung der Beweglichkeit. Mit Hilfe digitaler Menschmodelle können daraus resultierende Auswirkungen auf die Arbeitsgestaltung analysiert und bei der Planung von Arbeitssystemen berücksichtigt werden. Als Voraussetzung dafür müssen in Menschmodellen valide Daten integriert werden. Hierzu werden im Beitrag Datenquellen zur Beweglichkeit in Bezug zur altersbedingten Veränderung vorgestellt und deren Nutzung zur Ableitung von Referenzdaten für eine Integration in digitale Menschmodelle diskutiert. Als Quellen können Fachbücher, Primärstudien, Reviews und Meta-Analysen verwendet werden. Diese sind anhand von Kriterien zur Qualität und der Aufstellung von Referenzwerten zu bewerten. Im Ergebnis wird festgestellt, dass es wesentliche Unterschiede in der Studien- und Berichtsqualität gibt. Insbesondere fehlende Angaben zur Erhebung und der Studienpopulation erschweren die Studienbewertung und Einordnung hinsichtlich Referenzwerte. Referenzdaten unterscheiden sich auch hinsichtlich der Bereitstellung von alters- und geschlechtsspezifischen Angaben. Um eine adäquate Integration in digitale Menschmodelle vornehmen zu können, muss eine kritische Auseinandersetzung mit der Qualität der Erhebung und Repräsentativität der Daten erfolgen.