Journal: Journal of Biomechanics

Abbreviation

J. biomech.

Publisher

Elsevier

Journal Volumes

ISSN

0021-9290
1873-2380

Description

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Publications 1 - 10 of 167
  • Investigation of microdamage in murine bone under dynamic load
    Item type: Journal Article
    Meier, Matias; Vogel, Peter; Voide, Romain; et al. (2008)
    Journal of Biomechanics
  • Multimodal patient-cooperative rehabilitation robotics
    Item type: Other Conference Item
    Riener, R. (2006)
    Journal of Biomechanics
  • Foot kinematics during walking measured using bone and surface mounted markers
    Item type: Journal Article
    Nester, Christopher; Jones, Richard K.; Liu, Anmin; et al. (2007)
    Journal of Biomechanics
    The aim was to compare kinematic data from an experimental foot model comprising four segments ((i) heel, (ii) navicular/cuboid (iii) medial forefoot, (iv) lateral forefoot), to the kinematics of the individual bones comprising each segment. The foot model was represented using two different marker attachment protocols: (a) markers attached directly to the skin; (b) markers attached to rigid plates mounted on the skin. Bone data were collected for the tibia, talus, calcaneus, navicular, cuboid, medial cuneiform and first and fifth metatarsals (n=6). Based on the mean differences between the three data sets during stance, the differences between any two of the three kinematic protocols (i.e. bone vs skin, bone vs plate, skin vs plate) were >3° in only 35% of the data and >5° in only 3.5% of the data. However, the maximum difference between any two of the three protocols during stance was >3° in 100% of the data, >5° in 73% of the data and >8° in 23% of the data. Differences were greatest for motion of the combined navicular/cuboid relative to the calcaneus and the medial forefoot segment relative to the navicular/cuboid. The differences between the data from the skin and plate protocols were consistently smaller than differences between either protocol and the kinematic data for each bone comprising the segment. The pattern of differences between skin and plate protocols and the actual bone motion showed no systematic pattern. It is unlikely that one rigid body foot model and marker attachment approach is always preferable over another.
  • Assessing radiographic spinopelvic alignment parameters using motion capture
    Item type: Journal Article
    Büttiker , Nicola; Koch, David; Mündermann , Annegret; et al. (2025)
    Journal of Biomechanics
    While radiographic imaging is the gold standard for assessing spinopelvic alignment, it may not fully reflect symptom severity in patients with lumbar spinal stenosis (LSS) as patients employ dynamic compensatory strategies. This study aimed to develop a method to align static spinopelvic alignment parameters derived from motion capture with radiographic definitions. 27 patients underwent EOS radiography and motion capture analysis in a standardized posture. Radiopaque and retroreflective markers were placed on the same anatomical landmarks before EOS radiography and motion capture analysis, respectively. Offset angles were calculated to align motion capture-derived with radiographic parameters. Postural agreement between the two modalities was assessed using Bland-Altman analysis of the vertical distances between the posterior and anterior superior iliac spine markers (ASIS-PSIS) and the horizontal distances between the C7 and sacrum markers (SACR-C7). The influence of postural variation between modalities on alignment parameters was estimated using trigonometric analysis. Radiographic parameters differed notably from motion-capture derived parameters, particularly sacral slope, with an average offset of 31.1° (range: –0.4°–46.4°). The mean vertical ASIS-PSIS distance was −3.3 mm (LoA (limits of agreement): [−21.4; 14.8] mm) and the mean horizontal SACR-C7 distance was +4.9 mm (LoA: [−16.3; 26.1] mm), corresponding to maximum angular deviations of 5.9° for sacral slope and 3.7° for spine inclination. In conclusion, the large offset ranges underscore the need for radiography and individual offset corrections to approximate spinopelvic alignment parameters using motion capture. However, the close replication of the EOS posture highlights this method's potential for assessing spinopelvic alignment in dynamic conditions.
  • Feasibility of two-dimensional speckle-tracking echocardiography of aortic valve in patients with calcific aortic valve disease
    Item type: Journal Article
    Nemchyna, Olena; Knierim, Jan; Dandel, Michael; et al. (2021)
    Journal of Biomechanics
    Calcific aortic valve (AV) disease is associated with increased stiffness and reduced motion of AV leaflets, has a progressive course, and can develop into aortic stenosis (AS). Our aim was to evaluate whether two-dimensional speckle-tracking echocardiography (STE) may be used for the assessment of AV stiffness. We applied STE to AV leaflets in patients with various degrees of degenerative changes of AV and measured strain as an absolute value of the radial deformation of AV leaflets. Deformation of AV expressed as averaged AV strain was greatest in patients with a normal AV (23.4 ± 6.4%), compared to those with aortic sclerosis (12.9 ± 3.2%), moderate-to-severe AS (11.9 ± 4%), and severe AS (10.9 ± 3.5%) (p < 0.01). A non-linear relationship and moderate correlation of AV strain with transvalvular hemodynamic parameters was observed. In patients with mild-to-moderate AS, the strain of AV leaflets also correlated negatively with AV calcification (r = −0.59, p = 0.008). Good inter-observer agreement was obtained for averaged AV strain with a coefficient of variation of 0.15 and an interclass correlation coefficient of 0.94 (p < 0.0001). In this study we demonstrated that deformation of AV leaflets as assessed by STE might be a potential method for a non-invasive evaluation of AV biomechanical properties and of the progression of calcific aortic disease. Further development of the two-dimensional speckle tracking technique specifically for valve structures is needed to enable a better quantification of leaflet deformation.
  • Knee contact force alone is insufficient to validate joint mechanics in musculoskeletal models
    Item type: Journal Article
    Guo, Ning; Maas , Allan; Grupp , Thomas M.; et al. (2025)
    Journal of Biomechanics
    Musculoskeletal modelling plays a crucial role in understanding joint mechanics, particularly in applications such as surgical planning and implant design. As a common approach, these models are generally validated by assessing their ability to predict knee contact forces. However, such validation may not necessarily guarantee an accurate reconstruction of the complete joint biomechanics, where predicted kinematic patterns are often neglected, which is critical for understanding soft tissue loading and wear/interface conditions. In this study, we used a musculoskeletal model of the knee incorporating detailed representations of articular contact and soft tissue constraints to explore the relationship between the rigor of knee contact force validation and uncertainties in kinematic predictions. A Monte Carlo simulation with 1000 variations in muscle activation strategies was conducted, using a cost function that minimized the sum of squared muscle activations. The resulting outcomes of level walking and squatting simulations were then analysed. Our findings indicate that simulations yielding appropriate knee contact force estimates do not necessarily guarantee precise predictions of joint kinematics. Specifically, extending the acceptable root mean square error range for knee contact force estimates by 15 % of body weight led to an increase in the uncertainty of kinematic outcomes, reaching approximately 8 mm in translations and 10° in joint rotations. Stricter force validation criteria may mitigate, but not eliminate, inaccuracies in kinematic predictions. Our results highlight the need for comprehensive validation that includes both kinetic and kinematic data to achieve robust modelling outcomes. This is especially critical in applications requiring precise joint mechanics, such as implant design and in silico wear prediction.
  • In vivo blood flow measurements at bifurcations in the cerebral microvasculature
    Item type: Other Conference Item
    Obrist, Dominik; Landolt, Andrin; Wyss, Matthias; et al. (2012)
    Journal of Biomechanics
  • 3D printed clamps for fixation of spinal segments in biomechanical testing
    Item type: Journal Article
    Cornaz, Frédéric; Burkhard, Marco; Fasser, Marie-Rosa; et al. (2021)
    Journal of Biomechanics
    3D printed clamps provide multiple advantages compared to potting for the fixation of spinal specimens and in a recent study, superior fixation stability was reported. The aim of this study was to evaluate the fixation efficacy of 3D printed vertebra clamps during routine application and to present and evaluate a novel clamp for sacrum fixation. Further, public access to the template files is provided. 98 human single-level cadaveric specimens were biomechanically tested in flexion-extension (FE), lateral bending (LB), axial rotation (AR), anteroposterior shear (AS), lateral shear (LS) and axial compression-decompression (AC). Loading amplitudes were +/-7.5 Nm for FE, LB and AR, +/- 150 N for AS and LS and + 400/-100 N for AC. The novel sacrum clamp was used in 8 specimens. The median relative motion between clamps and specimens was 0.6 degrees in FE, 0.7 degrees in LB, 0.3 degrees in AR, 0.5 mm in AS, 0.5 mm in LS and 0.1 mm in AC. With sacrum clamps, the median relative motion was 0.3 degrees in FE, 0.1 degrees in LB, 0.08 degrees in AR, 0.8 mm in AS, 0.7 mm in LS and 0.2 mm in AC. The vertebra clamps used during routine testing provided better stability compared to the values in the literature in all six loading directions (p < 0.05). The sacrum clamp showed superior anchoring stability in three loading directions compared to the caudal vertebra clamps (p < 0.05), while inferior stability was measured in AS (p < 0.001). We conclude that 3D printed vertebra clamps and 3D printed sacrum clamps represent reliable methods for specimen fixation during routine biomechanical testing.
  • In Silico Quantification of the Elastic and Failure Properties of Bone Screws in Trabecular Bone
    Item type: Other Conference Item
    Steiner, Juri A.; Wenger, Christoph; Mueller, Thomas L.; et al. (2012)
    Journal of Biomechanics
  • Development of osteoinductive radiopaque hydrogel for 3D bioprinting and µCT visualization
    Item type: Other Conference Item
    Wüst, Silke; Godla, Maria E.; Hofmann, Sandra; et al. (2012)
    Journal of Biomechanics
Publications 1 - 10 of 167