The Poisson’s ratio of the nucleus pulposus is strain dependent

Part of the Soft Tissue Biomechanics Session this presentation is to characterise the true Poisson’s ratio of the nucleus pulposus is strain dependen

Poisson’s ratio of nucleus pulposus tissue : comparison of experimental results with a biphasic poroviscoelastic finite element model

This presentation looks at Poisson’s ratio of nucleus pulposus tissue, comparison of experimental results with a biphasic poroviscoelastic finite element mode

Effect of indenter velocity on the stiffness of articular cartilage

This presentation looks at the effect of indenter velocity on the stiffness of articular cartilag

Haversian canal structures can be associated with size effects in cortical bone

Prediction of periprosthetic failure may be improved by an improved model of bone elasticity which includes microstructural information. Micropolar theory facilitates such information to be included in a continuum model. We assessed the extent of bone’s micropolar behaviour in bending both numerically and experimentally. The numerical model was consistent with micropolar behaviour, and experimental results exhibited size effects that may have been confounded by surface roughness effects, as predicted numerically

Ethical Concerns of Heroism Training

Heroism training programs originated in the mid-2000s with the goal to “Train everyday heroes” (Heroic Imagination Project, 2017). Most participants of these programs are students between the ages of 10 and 20. Anecdotal and empirical evidence suggests that these programs may create more courageous and prosocial people (Heiner, 2018; Kohen & Sólo, 2019), however there is very little discussion in the emerging academic field of heroism science about the potential ethical concerns of training minors to be heroes (Beggan, 2019; Franco & Zimbardo, 2016; Franco et al., 2017). With the growth of heroism science scholarship, it would be wise to examine and offer best practices for the ethical training of heroism with minors. Heroic action is inherently risky, and while training programs currently discuss mortality and risk assessment, minors have not developed the neural or cognitive capacity to assess risks as adults can. Furthermore, the content and goals of heroism training may go against schools’ and parents’ wishes. Heroism training programs also have the potential to make heroism seem glamorous, which could lead some participants to seek out, or create, situations requiring heroic action. The paper discusses these, and other, ethical concerns in training minors to be heroes. The paper concludes with a variety of best practice recommendations for heroism training programs working with minors including; obtaining parent consent for training, working to improve minors’ risk assessment abilities, domain specific training, and involving parents and other relevant stakeholders in the heroism training process

Modelling micropolar behaviour in cortical bone

This presentation looks at modelling micropolar behaviour in cortical bon

Non-invasive assessment of lower limb alignment is accurate for pre-operative planning and post-operative follow up

Knee alignment is a fundamental measurement in the assessment, monitoring and surgical management of patients with OA. In spite of extensive research into the consequences of malalignment, there is a lack of data regarding the potential variation between supine and standing (functional) conditions. The purpose of this study was to explore this relationship in asymptomatic, osteoarthritic and prosthetic knees. Our hypothesis was that the change in alignment of these three groups would be different. Infrared position capture was used to assess knee alignment for 30 asymptomatic controls and 31 patients with OA, before and after TKA. Coronal and sagittal mechanical femorotibial (MFT) angles in extension (negative values varus/hyperextension) were measured supine and in bi-pedal stance and changes analysed using a paired t-test. To quantify this change in 3D, vector plots of ankle centre displacement relative to the knee centre were produced. Alignment in both planes changed significantly from supine to standing for all three groups, most frequently towards relative varus and extension. In the coronal plane, the mean±SD(°) of the supine/standing MFT angles was 0.1±2.5/−1.1±3.7 for asymptomatic (p=0.001), −2.5±5.7/−3.6±6.0 for osteoarthritic (p=0.009) and −0.7±1.4/ −2.5±2.0 for prosthetic knees (p<0.001). In the sagittal plane, the mean±SD(°) of the supine/standing MFT angles was −1.7±3.3/−5.5±4.9 for asymptomatic (p<0.001), 7.7±7.1/1.8±7.7 for osteoarthritic (p<0.001) and 6.8±5.1/1.4±7.6 for prosthetic knees (p<0.001). The vector plots showed that the trend of relative varus and extension in stance was similar in overall magnitude and direction between the groups. The similarities between each group did not support our hypothesis. The consistent kinematic pattern for different knee types suggests that soft tissue restraints rather than underlying joint deformity may be more influential in dynamic control of alignment from lying to standing. This potential change should be considered when positioning TKA components on supine limbs as post-operative functional alignment may be different

Learning Together 1: an educational model for training GPs, paediatricians: initial findings.

Learning Together is primarily an educational intervention, where paediatric registrars [SpRs] and General Practice (GP) registrars [GPSTs] see children together in a primary care setting. Over a six month period in 2013/2014, 44 learning pairs were set up mainly in North East and Central London. Proof of concept for the model at scale was achieved. Reported learning demonstrated: clinical learning themes of new knowledge, skill and communication skills; and collaborative themes of ongoing collaboration, satisfaction with team working and change in attitudes. These themes were identified in both sets of trainees. The self-reported learning is backed up by the results of a retrospective notes review of four common conditions based on NICE guidelines; constipation, asthma, feverish illness and eczema (CAFE). Guidance adherence improved from 57% before the intervention in solo GP training consultations to 72% during the joint clinic intervention (p < 0.01). After the intervention when the GP registrars returned to normal consultations, guidance adherence was 77% compared to before the intervention (p < 0.01). In addition 99% of the parents, who handed in feedback forms or took part in interviews, reported a good experience of care, and 87% reported increased confidence to manage their children's health following the consultation. A second, linked article examines the cost utility of Learning Together in its South London extension

Concurrent validity and test-retest reliability of the Polhemus Liberty for the measurement of spinal range

This paper discusses concurrent validity and test-retest reliability of the Polhemus Liberty for the measurement of spinal range.It was presented at the International Society of Biomechanics, XXII World Congress, in 2009

Assessment of seating forces imparted through daily activity by children with special needs

Extensor spasms regularly occur in spastic Cerebral Palsy (CP) children making their bodies unbalanced and causing wheelchair instability. Furthermore the child may be uncomfortable as a result of the high contact forces potentially causing pain and injury, which will impair their functional ability. Dynamic seating systems have been designed to absorb the energy associated with these spasms. For people with physical disabilities, especially patients who have strong extensor spasticity, the dynamic design prevents pressure ulcers and injury from impact. However, the quantitative effectiveness and impact of using dynamic components has yet to be established. Therefore our objective is to compare the imparted forces on equivalent rigid and dynamic seating systems, to understand the interactions between force, wheelchair compliance and physical activity throughout a four hour session of non-laboratory based daily living