Instantaneous centers of rotation for lumbar segmental extension in vivo

Aiyangar, Ameet; Zheng, Liying; Anderst, William; Zhang, Xudong

doi:10.1016/j.jbiomech.2016.12.021

Cited by 29 publications

(29 citation statements)

References 47 publications

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“…supported by the model predictions. Specifically, the study corroborated previous conjecture based on experimental observations of lumbar segmental kinematics (Aiyangar et al, 2017):…”

Section: °15°30°45°( A) Maximum Deviations Of Compression Forces ([Nsupporting

confidence: 90%

“…Level-specific definitions of AP and SI direction corresponded with the inferior vertebra's local coordinate system. The covered range of COR variation approximately represents 50% of the vertebral body size and is in accordance with physiological COR migration distances during extension movement as measured in in vivo kinematic assessments (Aiyangar et al, 2017). To avoid bushing forces caused by the translation of CORs the joint bushings were repositioned to match with the new joint centers.…”

Section: Methodssupporting

confidence: 60%

“…Indeed, representing lumbar joints as rotational joints with a fixed COR is almost universally applied (Daggfeldt and Thorstensson, 2003;De Zee et al, 2007;Delp et al, 2007;Senteler et al, 2016;Zhu et al, 2013) and is one of the basic design aspects featured in modern prosthetic disc replacements (Dreischarf et al, 2015). Recent improvements in dynamic imaging techniques (Ahmadi et al, 2009;Aiyangar et al, 2014;Anderst et al, 2008;Wu et al, 2014), and the ability to compute instantaneous axes of rotation for smaller rotational step sizes (Aiyangar et al, 2017;Baillargeon and Anderst, 2013;Ellingson and Nuckley, 2015), however, has rekindled interest in utilizing instantaneous COR patterns for identifying pathologies such as lumbar instability (Ahmadi et al, 2009) and degenerative spondylolisthesis (Ellingson and Nuckley, 2015). At the same time, Zander and co-workers demonstrated the inaccuracy of the accepted ''average" COR in locating the point where muscle activity and joint reaction forces are minimized for a static upright pose, using the center of reaction concept (Zander et al, 2016).…”

Section: Discussionmentioning

confidence: 99%

“…Several studies have shown that lumbar segments exhibit coupled translations associated with rotational movement. Mapping the migration path of the instantaneous centers of rotation (ICRs) between two adjacent vertebrae over a given motion -the centrode -has been shown to be a reasonable way to quantitatively describe such coupled motion (Aiyangar et al, 2017;Gertzbein et al, 1984;Ogston et al, 1986). More importantly, the ICR have been shown to have a biological basis linking aberrations in its location to anatomical and pathological factors (Bogduk et al, 1995;Schneider et al, 2005), based on its strong association with the center of reaction (Gracovetsky et al, 1987;Zander et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

“…The longstanding limitations regarding lacking data is being overcome with recent developments in direct measurement of bone kinematics using dynamic radiographic techniques, particularly during in vivo load bearing functional activities (Ahmadi et al, 2009;Aiyangar et al, 2014;Anderst et al, 2008;Wu et al, 2014). Very recently, Aiyangar et al mapped the migration patterns of the instantaneous COR during a lifting task using dynamic stereo radiography (DSX) to show that the COR generally migrates from an anterior-most location towards a posterior location during a progressive extension movement from a forward flexed to an upright position (Aiyangar et al, 2017). Further they also demonstrated that the average COR superior-inferior (SI) location is level-specific, with the average SI coordinates tending to be located in an increasingly superior location as one moves inferiorly from L2L3 toward the lowest anatomical segment (L5S1).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Sensitivity of intervertebral joint forces to center of rotation location and trends along its migration path

Senteler

Aiyangar

Weisse

et al. 2018

Journal of Biomechanics

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Translational vertebral motion during functional tasks manifests itself in dynamic loci for center of rotation (COR). A shift of COR affects moment arms of muscles and ligaments; consequently, muscle and joint forces are altered. Based on posture- and level-specific trends of COR migration revealed by in vivo dynamic radiography during functional activities, it was postulated that the instantaneous COR location for a particular joint is optimized in order to minimize the joint reaction forces. A musculoskeletal multi-body model was employed to investigate the hypotheses that (1) a posterior COR in upright standing and (2) an anterior COR in forward flexed posture leads to optimized lumbar joint loads. Moreover, it was hypothesized that (3) lower lumbar levels benefit from a more superiorly located COR. The COR in the model was varied from its initial position in posterior-anterior and inferior-superior direction up to ±6 mm in steps of 2 mm. Movement from upright standing to 45° forward bending and backwards was simulated for all configurations. Joint reaction forces were computed at levels L2L3 to L5S1. Results clearly confirmed hypotheses (1) and (2) and provided evidence for the validity of hypothesis (3), hence offering a biomechanical rationale behind the migration paths of CORs observed during functional flexion/extension movement. Average sensitivity of joint force magnitudes to an anterior shift of COR was +6 N/mm in upright and -21 N/mm in 30° forward flexed posture, while sensitivity to a superior shift in upright standing was +7 N/mm and -8N/mm in 30° flexion. The relation between COR loci and joint loading in upright and flexed postures could be mainly attributed to altered muscle moment arms and consequences on muscle exertion. These findings are considered relevant for the interpretation of COR migration data, the development of numerical models, and could have an implication on clinical diagnosis and treatment or the development of spinal implants.

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“…supported by the model predictions. Specifically, the study corroborated previous conjecture based on experimental observations of lumbar segmental kinematics (Aiyangar et al, 2017):…”

Section: °15°30°45°( A) Maximum Deviations Of Compression Forces ([Nsupporting

confidence: 90%

Section: Methodssupporting

confidence: 60%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Sensitivity of intervertebral joint forces to center of rotation location and trends along its migration path

Senteler

Aiyangar

Weisse

et al. 2018

Journal of Biomechanics

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ISSLS Prize in Bioengineering Science 2021: in vivo sagittal motion of the lumbar spine in low back pain patients—a radiological big data study

et al. 2021

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Muscle-driven and torque-driven centrodes during modeled flexion of individual lumbar spines are disparate

Rockenfeller

Müller

Damm

et al. 2020

Biomech Model Mechanobiol

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Lumbar spine biomechanics during the forward-bending of the upper body (flexion) are well investigated by both in vivo and in vitro experiments. In both cases, the experimentally observed relative motion of vertebral bodies can be used to calculate the instantaneous center of rotation (ICR). The timely evolution of the ICR, the centrode, is widely utilized for validating computer models and is thought to serve as a criterion for distinguishing healthy and degenerative motion patterns. While in vivo motion can be induced by physiological active structures (muscles), in vitro spinal segments have to be driven by external torque-applying equipment such as spine testers. It is implicitly assumed that muscle-driven and torque-driven centrodes are similar. Here, however, we show that centrodes qualitatively depend on the impetus. Distinction is achieved by introducing confidence regions (ellipses) that comprise centrodes of seven individual multi-body simulation models, performing flexion with and without preload. Muscle-driven centrodes were generally directed superior–anterior and tail-shaped, while torque-driven centrodes were located in a comparably narrow region close to the center of mass of the caudal vertebrae. We thus argue that centrodes resulting from different experimental conditions ought to be compared with caution. Finally, the applicability of our method regarding the analysis of clinical syndromes and the assessment of surgical methods is discussed.

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Instantaneous centers of rotation for lumbar segmental extension in vivo

Cited by 29 publications

References 47 publications

Sensitivity of intervertebral joint forces to center of rotation location and trends along its migration path

Sensitivity of intervertebral joint forces to center of rotation location and trends along its migration path

ISSLS Prize in Bioengineering Science 2021: in vivo sagittal motion of the lumbar spine in low back pain patients—a radiological big data study

Muscle-driven and torque-driven centrodes during modeled flexion of individual lumbar spines are disparate

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