William R. Taylor


Last Name

Taylor

First Name

William R.

ORCID

0000-0003-4060-4098

Organisational unit

03994 - Taylor, William R. / Taylor, William R.

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2012 - 2019942020 - 2026123
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Publications 1 - 10 of 217
  • Complex curvature analysis of the middle spinal line in non-ionizing 3d diagnosis of adolescent idiopathic disorders
    Item type: Conference Paper
    Cukovic, Sasa; Ghionea, Ionuţ; Luković, Vanja; et al. (2018)
    BIBE 2018; International Conference on Biological Information and Biomedical Engineering
  • The role of limb alignment on tibio-femoral kinematics: A dynamic videofluroscopy study
    Item type: Other Conference Item
    Postolka, Barbara; Taylor, William R.; List, Renate; et al. (2021)
    Book of Abstracts: 26th Congress of the European Society of Biomechanics (ESB 2021)
  • Does Subthalamic Deep Brain Stimulation Impact Asymmetry and Dyscoordination of Gait in Parkinson's Disease?
    Item type: Journal Article
    Ravi, Deepak K.; Baumann, Christian R.; Bernasconi, Elena; et al. (2021)
    Neurorehabilitation and Neural Repair
    Background. Subthalamic deep brain stimulation (STN-DBS) is an effective treatment for selected Parkinson's disease (PD) patients. Gait characteristics are often altered after surgery, but quantitative therapeutic effects are poorly described. Objective. The goal of this study was to systematically investigate modifications in asymmetry and dyscoordination of gait 6 months postoperatively in patients with PD and compare the outcomes with preoperative baseline and to asymptomatic controls without PD. Methods. A convenience sample of thirty-two patients with PD (19 with postural instability and gait disorder (PIGD) type and 13 with tremor dominant disease) and 51 asymptomatic controls participated. Parkinson patients were tested prior to the surgery in both OFF and ON medication states, and 6-months postoperatively in the ON stimulation condition. Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) I to IV and medication were compared to preoperative conditions. Asymmetry ratios, phase coordination index, and walking speed were assessed. Results. MDS-UPDRS I to IV at 6 months improved significantly, and levodopa equivalent daily dosages significantly decreased. STN-DBS increased step time asymmetry (hedges' g effect sizes [95% confidence interval] between pre- and post-surgery: .27 [-.13, .73]) and phase coordination index (.29 [-.08, .67]). These effects were higher in the PIGD subgroup than the tremor dominant (step time asymmetry: .38 [-.06, .90] vs .09 [-.83, 1.0] and phase coordination index: .39 [-.04, .84] vs .13 [-.76, .96]). Conclusions. This study provides objective evidence of how STN-DBS increases asymmetry and dyscoordination of gait in patients with PD and suggests motor subtypes-associated differences in the treatment response.
  • The Restoration of Passive Rotational Tibio-Femoral Laxity after Anterior Cruciate Ligament Reconstruction
    Item type: Journal Article
    Moewis, Philippe; Duda, Georg N.; Jung, Tobias; et al. (2016)
    PLoS ONE
    While the anterior cruciate ligament (ACL) is considered one of the most important ligaments for providing knee joint stability, its influence on rotational laxity is not fully understood and its role in resisting rotation at different flexion angles in vivo remains unknown. In this prospective study, we investigated the relationship between in vivo passive axial rotational laxity and knee flexion angle, as well as how they were altered with ACL injury and reconstruction. A rotometer device was developed to assess knee joint rotational laxity under controlled passive testing. An axial torque of ±2.5Nm was applied to the knee while synchronised fluoroscopic images of the tibia and femur allowed axial rotation of the bones to be accurately determined. Passive rotational laxity tests were completed in 9 patients with an untreated ACL injury and compared to measurements at 3 and 12 months after anatomical single bundle ACL reconstruction, as well as to the contralateral controls. Significant differences in rotational laxity were found between the injured and the healthy contralateral knees with internal rotation values of 8.7°±4.0° and 3.7°±1.4° (p = 0.003) at 30° of flexion and 9.3°±2.6° and 4.0°±2.0° (p = 0.001) at 90° respectively. After 3 months, the rotational laxity remained similar to the injured condition, and significantly different to the healthy knees. However, after 12 months, a considerable reduction of rotational laxity was observed towards the levels of the contralateral controls. The significantly greater laxity observed at both knee flexion angles after 3 months (but not at 12 months), suggests an initial lack of post-operative rotational stability, possibly due to reduced mechanical properties or fixation stability of the graft tissue. After 12 months, reduced levels of rotational laxity compared with the injured and 3 month conditions, both internally and externally, suggests progressive rotational stability of the reconstruction with time.
  • A frame orientation optimisation method for consistent interpretation of kinematic signals
    Item type: Journal Article
    Ortigas Vásquez, Ariana; Taylor, William R.; Maas, Allan; et al. (2023)
    Scientific Reports
    In clinical movement biomechanics, kinematic data are often depicted as waveforms (i.e. signals), characterising the motion of articulating joints. Clinically meaningful interpretations of the underlying joint kinematics, however, require an objective understanding of whether two different kinematic signals actually represent two different underlying physical movement patterns of the joint or not. Previously, the accuracy of IMU-based knee joint angles was assessed using a six-degrees-of-freedom joint simulator guided by fluoroscopy-based signals. Despite implementation of sensor-to-segment corrections, observed errors were clearly indicative of cross-talk, and thus inconsistent reference frame orientations. Here, we address these limitations by exploring how minimisation of dedicated cost functions can harmonise differences in frame orientations, ultimately facilitating consistent interpretation of articulating joint kinematic signals. In this study, we present and investigate a frame orientation optimisation method (FOOM) that aligns reference frames and corrects for cross-talk errors, hence yielding a consistent interpretation of the underlying movement patterns. By executing optimised rotational sequences, thus producing angular corrections around each axis, we enable a reproducible frame definition and hence an approach for reliable comparison of kinematic data. Using this approach, root-mean-square errors between the previously collected (1) IMU-based data using functional joint axes, and (2) simulated fluoroscopy-based data relying on geometrical axes were almost entirely eliminated from an initial range of 0.7°–5.1° to a mere 0.1°–0.8°. Our results confirm that different local segment frames can yield different kinematic patterns, despite following the same rotation convention, and that appropriate alignment of reference frame orientation can successfully enable consistent kinematic interpretation.
  • Restoring range of motion in reduced acetabular version by increasing femoral antetorsion – What about joint load?
    Item type: Journal Article
    Roth, Tabitha; Rahm, Stefan; Jungwirth-Weinberger, Anna; et al. (2021)
    Clinical Biomechanics
    Background Acetabular retroversion results in reduced range of motion, and is thought to contribute to femoroacetabular impingement. Severe retroversion can be corrected with a periacetabular osteotomy, which is a technically demanding intervention. In this study, we investigated whether increasing femoral antetorsion is a potential alternative to restore the range of motion and how this approach would affect hip joint loading. Methods Six different finite element models of the same subject were built from MRI and used to simulate different load scenarios during stance phase, including healthy and pathological configurations with different acetabular version and femoral torsion angles. The subject's gait was analysed in our gait lab and motion data as well as joint reaction forces were integrated into the model. Hip range of motion, hip abductor muscle forces as well as localization and magnitude of hip joint loads were determined. Findings The negative effects of acetabular retroversion on hip range of motion including flexion and internal rotation can be reversed by increasing femoral anteversion. The rotation of the femur furthermore affected muscular functionality by shortening the moment arms of the hip abductor muscles, resulting in increased abductor muscle forces, joint reaction forces and hip joint loading. Interpretation Even though increased femoral antetorsion can compensate for the loss of hip range of motion due to reduced acetabular version, rotational ostotomy of the proximal femur is likely to alter muscular moment arms and therefore increase hip joint load, conflicting the goal of a long-term healthy joint.
  • Occupational sitting behaviour and its relationship with back pain - A pilot study
    Item type: Journal Article
    Lorenzetti, Silvio; Zemp, Roland; Fliesser, Michael; et al. (2016)
    Applied Ergonomics
    Nowadays, working in an office environment is ubiquitous. At the same time, progressively more people suffer from occupational musculoskeletal disorders. Therefore, the aim of this pilot study was to analyse the influence of back pain on sitting behaviour in the office environment. A textile pressure mat (64-sensor-matrix) placed on the seat pan was used to identify the adopted sitting positions of 20 office workers by means of random forest classification. Additionally, two standardised questionnaires (Korff, BPI) were used to assess short and long-term back pain in order to divide the subjects into two groups (with and without back pain). Independent t-test indicated that subjects who registered back pain within the last 24 h showed a clear trend towards a more static sitting behaviour. Therefore, the developed sensor system has successfully been introduced to characterise and compare sitting behaviour of subjects with and without back pain.
  • In vivo spinal posture during sitting upright and reclined in an office chair
    Item type: Other Conference Item
    Zemp, Roland; Taylor, William R.; Lorenzetti, Silvio (2013)
  • The Effects of Selective Dorsal Rhizotomy on Balance and Symmetry of Gait in Children with Cerebral Palsy
    Item type: Journal Article
    Rumberg, Franziska; Bakir, Mustafa Sinan; Taylor, William R.; et al. (2016)
    PLoS ONE
    Aim Cerebral palsy (CP) is associated with dysfunction of the upper motor neuron and results in balance problems and asymmetry during locomotion. Selective dorsal rhizotomy (SDR) is a surgical procedure that results in reduced afferent neuromotor signals from the lower extremities with the aim of improving gait. Its influence on balance and symmetry has not been assessed. The aim of this prospective cohort study was to evaluate the impact of SDR on balance and symmetry during walking. Methods 18 children (10 girls, 8 boys; age 6 years (y) 3 months (m), SD 1y 8m) with bilateral spastic CP and Gross Motor Function Classification System levels I to II underwent gait analysis before and 6 to 12 months after SDR. Results were compared to 11 typically developing children (TDC; 6 girls, 5 boys; age 6y 6m, SD 1y 11m). To analyse balance, sway velocity, radial displacement and frequency were calculated. Symmetry ratios were calculated for balance measures and spatio-temporal parameters during walking. Results Most spatio-temporal parameters of gait, as well as all parameters of balance, improved significantly after SDR. Preoperative values of symmetry did not vary considerably between CP and TDC group and significant postoperative improvement did not occur. Interpretation The reduction of afferent signalling through SDR improves gait by reducing balance problems rather than enhancing movement symmetry.
  • Spatial Navigation as a Digital Marker for Clinically Differentiating Cognitive Impairment Severity
    Item type: Working Paper
    Colombo, Giorgio; Minta, Karolina; Taylor, William R.; et al. (2025)
    medRxiv
    Navigation impairments emerge early in Alzheimer’s disease, but assessments targeting these deficits remain underutilised or impractical for cognitive screening. The Spatial Performance Assessment for Cognitive Evaluation (SPACE) is a digital tool that evaluates spatial navigation deficits associated with cognitive impairment. In a memory clinic and community cohort (n = 300), SPACE reliably distinguished Clinical Dementia Rating levels, exceeding the accuracy of demographic models and matching or surpassing most traditional neuropsychological tests. Including SPACE significantly increased the AUC for distinguishing between no dementia from mild dementia (0.76 to 0.94), no dementia from moderate dementia (0.79 to 0.95), and questionable dementia from mild dementia (0.70 to 0.91), all with consistently high sensitivity and specificity. A short version of SPACE (< 11 minutes) reduced administration time by 40% while maintaining high diagnostic accuracy. These findings highlight the potential of digital navigation assessments to advance early detection, contributing to scalable and accessible healthcare.
Publications 1 - 10 of 217