Journal: Clinical Biomechanics

Abbreviation

Clin Biomech

Publisher

Elsevier

Journal Volumes

ISSN

0268-0033
1879-1271

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Publications1 - 10 of 35
  • Moment arms of forearm rotators
    Item type: Journal Article
    Bremer, Anne K.; Sennwald, Gontran R.; Favre, Philippe; et al. (2006)
    Clinical Biomechanics
  • A review on the mechanical quality of articular cartilage
    Item type: Journal Article
    Knecht, Sven; Vanwanseele, Benedicte; Stüssi, Edgar (2006)
    Clinical Biomechanics
  • Age and activity but not lumbar spinal stenosis and muscle fatigue affect sagittal spinal alignment: A pilot study
    Item type: Journal Article
    Koch, David; Nüesch, Corina; Ignasiak, Dominika; et al. (2025)
    Clinical Biomechanics
    Background: Ageing is associated with changes in spinal alignment. Lumbar spinal stenosis may alter spinal alignment due to pain, muscle atrophy and fatigue. While spinal alignment and motion are crucial in lumbar spinal stenosis, the effects of age, activity, and muscle fatigue on spinal alignment remain unclear. This study investigates these factors using motion capture analysis. Methods: In 11 patients with lumbar spinal stenosis (5 M/6 W; age, 71 ± 9 years; body mass index, 29 ± 5 kg/m2), 10 older controls (5 M/5F; 65 ± 5 years; 25 ± 6 kg/m2), and 10 young controls (5 M/5F; 26 ± 2 years; 22 ± 2 kg/m2), spinal alignment was assessed during standing and walking before and after a modified Biering-Sørensen test using reflective markers. The curvature of the thoracic and lumbar spine was modelled using a cubic polynomial. Spine inclination, thoracic kyphosis, lumbar lordosis and pelvic tilt were used to describe spinal alignment. The effects of group, activity and paraspinal muscle fatigue were investigated using bootstrapped mixed-effect models. Findings: Patients and older controls had greater spine inclination than young controls. Spinal alignment did not differ between patients and older controls. Dynamic activity increased spine inclination, thoracic kyphosis, and pelvic tilt across all groups. Compared to non-fatigued conditions, significant spine inclination increases and lumbar lordosis decreases occurred with fatigue. A significant interaction effect for group and activity was found between patients and young controls. Interpretation: Our findings suggest that age and activity, rather than lumbar spinal stenosis and muscle fatigue, play a critical role in spinal alignment. Further studies are warranted to investigate the underlying mechanisms. ClinicalTrials.gov ID NCT05309447.
  • Biomechanical background and clinical observations of rotational malalignment in TKA: Literature review and consequences
    Item type: Review Article
    Zihlmann, Monika Silvia; Stacoff, Alex; Romero, José; et al. (2005)
    Clinical Biomechanics
  • Novel passive ankle-foot prosthesis mimics able-bodied ankle angles and ground reaction forces
    Item type: Journal Article
    Schlafly, Milli; Reed, Kyle B. (2020)
    Clinical Biomechanics
    Background: During gait, the human ankle both bends with ease and provides push-off forces that facilitate forward motion. The ankle is crucial for support, stabilization, and adapting to different slopes and terrains. Individuals with lower limb amputation require an ankle-foot prosthesis for basic mobility. Methods: Inspired by the role of the ankle-foot in an able-bodied gait, the 3D printed Compliant and Articulating Prosthetic Ankle (CAPA) foot was designed. It consists of four articulating components connected by torsion springs and produces forces that are dependent on the ankle angle. Using the Computer Assisted Rehabilitation Environment, able-bodied individuals walked wearing a prosthetic simulator with the Solid Ankle Cushioned Heel foot, Renegade® AT, and multiple versions of the CAPA. These versions test compliant vs. stiff, small vs. large rocker radius, and pretension vs. none. We hypothesized that the CAPA would have larger ankle range of motion, push-off forces, and braking forces. Findings: Compared to existing prostheses, the novel prosthesis exhibits greater and significantly different ankle range of motion and sagittal plane ground reaction forces than existing prostheses during gait. Nine out of ten individuals prefer the novel prosthesis to the existing prostheses, and there is a statistically significant difference in difficulty level ratings. Interpretation: By providing a personalizable and passive alternative to existing designs, the CAPA could improve the quality of life for the growing number of individuals living with limb loss in the United States and around the world.
  • Airway morphology and inspiratory flow features in the early stages of Chronic Obstructive Pulmonary Disease
    Item type: Journal Article
    Van de Moortele, Tristan; Goerke, Ute; Wendt, Chris H.; et al. (2019)
    Clinical Biomechanics
    Background Chronic Obstructive Pulmonary Disease (COPD) is among the leading causes of death worldwide. Inhaled pollutants are the prime risk factor, but the pathogenesis and progression of the diseased is poorly understood. Most studies on the disease onset and trajectory have focused on genetic and molecular biomarkers. Here we investigate the role of the airway anatomy and the consequent respiratory fluid mechanics on the development of COPD. Methods We segmented CT scans from a five-year longitudinal study in three groups of smokers (18 subjects each) having: (i) minimal/mild obstruction at baseline with declining lung function at year five; (ii) minimal/mild obstruction at baseline with stable function, and (iii) normal and stable lung function over the five year period. We reconstructed the bronchial trees up to the 7th generation, and for one subject in each group we performed MRI velocimetry in 3D printed models. Findings The subjects with airflow obstruction at baseline have smaller airway diameters, smaller child-to-parent diameter ratios, larger length-to-diameter ratios, and smaller fractal dimensions. The differences are more significant for subjects that develop severe decline in pulmonary function. The secondary flows that characterize lateral dispersion along the airways are found to be less intense in the subjects with airflow obstruction. Interpretation These results indicate that morphology of the conducting airways and inspiratory flow features are correlated with the status and progression of COPD already at an early stage of the disease. This suggests that imaging-based biomarkers may allow a pre-symptomatic diagnosis of disease progression.
  • Friction between finger flexor tendons and the pulley system in the crimp grip position
    Item type: Journal Article
    Moor, Beat K.; Nagy, Ladislav; Snedeker, Jess Gerrit; et al. (2009)
    Clinical Biomechanics
  • An algorithm for estimation of shoulder muscle forces for clinical use
    Item type: Journal Article
    Favre, Philippe; Sheikh, Ralph; Fucentese, Sandro F.; et al. (2005)
    Clinical Biomechanics
  • The quantitative influence of current treatment options on patellofemoral stability in patients with trochlear dysplasia and symptomatic patellofemoral instability - a finite element simulation
    Item type: Journal Article
    Kaiser, Dominik; Trummler, Linus; Götschi, Tobias; et al. (2021)
    Clinical Biomechanics
    Background Trochlear dysplasia is highly associated with patellofemoral instability. The goal of conservative and surgical treatment is to stabilize the patella while minimizing adverse effects. However, there is no literature investigating the quantitative influence of different treatment options on patellofemoral stability in knees with trochlear dysplasia. We created and exploited a range of finite element models to address this gap in knowledge. Methods MRI data of 5 knees with trochlear dysplasia and symptomatic patellofemoral instability were adapted into this previously established model. Vastus medialis obliquus strengthening as well as double-bundle medial patellofemoral ligament reconstruction and the combination of medial patellofemoral ligament reconstruction and trochleoplasty were simulated. The force necessary to dislocate the patella by 10 mm and fully dislocate the patella was calculated in different flexion angles. Findings Our model predicts a significant increase of patellofemoral stability at the investigated flexion angles (0°-45°) for a dislocation of 10 mm and a full dislocation after medial patellofemoral ligament reconstruction and the combination of medial patellofemoral ligament reconstruction and trochleoplasty compared to trochleodysplastic (P = 0.01) and healthy knees (P = 0.01–0.02). Vastus medialis obliquus strengthening has a negligible effect on patellofemoral stability. Interpretations This is the first objective quantitative biomechanical evidence supporting the place of medial patellofemoral ligament reconstruction and medial patellofemoral ligament reconstruction combined with trochleoplasty in patients with symptomatic patellofemoral instability and trochlear dysplasia type B. Vastus medialis obliquus strengthening has a negligible effect on patellar stability at a low total quadriceps load of 175 N.
  • Patellofemoral instability in trochleodysplastic knee joints and the quantitative influence of simulated trochleoplasty - A finite element simulation
    Item type: Journal Article
    Kaiser, Dominik; Trummler, Linus; Götschi, Tobias; et al. (2021)
    Clinical Biomechanics
    Background Patellofemoral instability is a debilitating condition mainly affecting young patients and has been correlated with trochlear dysplasia. It can occur when the patella is insufficiently guided through its range of motion. Currently, there is no literature describing patellofemoral stability in trochleodysplastic knees and the effect of isolated trochleoplasty on patellofemoral stability. Methods The effect of isolated trochleoplasty in trochleodysplastic knees of patients with symptomatic patellofemoral instability was investigated using a quasi-static finite element model. MRI data of five healthy knees were segmented, meshed and a finite element analysis was performed in order to validate the model. A second validation was performed by comparing simulated patellofemoral kinematics to in-vivo values obtained from upright- weight bearing CT scans. Subsequently, five trochleodysplastic knees were modelled before and after simulated trochleoplasty. The force necessary to dislocate the patella by 10 mm and to fully dislocate the patella was calculated in various knee flexion angles between 0 and 45°. Findings The developed models successfully predicted outcome values within the range of reference values from literature. Lateral stability was significantly lower in trochleodysplastic knees compared to healthy knees. Trochleoplasty was determined to significantly increase the force necessary to dislocate the patella in trochleodysplastic knees to comparable values as in healthy knees. Interpretation This is the first study to investigate lateral patellofemoral stability in patients with symptomatic patellofemoral instability and dysplasia of the trochlear groove. We confirm that patellofemoral stability is significantly lower in trochleodysplastic knees than in healthy knees. Trochleoplasty increases patellofemoral stability to levels similar to healthy.
Publications1 - 10 of 35