THE RELIABILITY AND VARIABILITY OF THREE-DIMENSIONAL TlBlAL ACCELERATION DURING RUNNING

Axial and resultant peak tibial acceleration might be useful for screening/monitoring runners at risk of lower limb injury. This study quantified between-session reliability and variability of axial and resultant peak tibial acceleration during running. Fourteen runners completed four running speeds at two testing sessions seven days apart with tri-axial wireless accelerometers attached to the tibia. Average mean differences between sessions across all four speeds (for the right or left side) were 4.5-5.7% (ES 0.01-0.17; ICC 0.73-0.95; CV% 7.5-1 7.9) for axial and 0.9-5.1 % (ES 0.01 -0.1 2; ICC 0.84-0.97; CV% 5.913.9)) for resultant peak tibial acceleration. While both axial and resultant peak tibial acceleration are reliable and therefore appropriate for monitoring and assessment of an intervention, resultant peak tibial acceleration should be preferentially used

SOFT TISSUE LOADS AT THE HUMAN KNEE DURING RUNNING AND CUTTING MANOEUVRES

Tensile forces on the ACL increase when the knee is in an extended posture and required to accommodate applied moments in flexion, varus, valgus and/or internal rotation. However, the loading of knee joint support structures during sporting actions that are related to non-contact injuries are largely unknown. We studied external loading of the knee during running, side-stepping and cross-over cutting in 10 male subjects under both pre-planned and unanticipated conditions. Soft tissue structures of the knee were exposed to high FE, VV and IE applied moments during the cutting tasks, especially when performed in the unanticipated condition. Whilst muscle activation could accommodate some of this applied load, soft tissue structures were particularly vulnerable during the cross-over cut task where the residual loads were high

THE EFFECT OF LOWER LIMB TRAINING ON MUSCULAR SUPPORT OF THE KNEE AND RISK OF ANTERIOR CRUCIATE LIGAMENT INJURY.

An intervention study was performed to investigate the effect of lower-limb training programs on knee muscle activation patterns and their potential to support the knee load during running and cutting manoeuvres. It is known that balance training can reduce ACL injury but the underlying mechanisms are unknown. The effects that strength training has on support for the knee joint during sporting manoeuvres are also not known. Analysis of activation levels and patterns of leg muscles during running, sidestepping and crossover-cutting manoeuvres prior to and following 12-week training programs revealed important results in terms of potential support of load on the ACL. Balance training increased co-contraction and supportive muscle activation patterns, as did the combination of machine and balance training to a lesser extent. The strength training programs tended to reduce co-contraction and were associated with changes which would lead to less stability of the knee during sporting manoeuvres. It is recommended that balance training should be implemented to reduce an athlete’s risk of ACL injury

SCIENCE TO COMMERCIALISATION –TRANSLATING SCIENCE TO COMMERCIAL OUTCOMES

Validation is a critical component to the scientific method and translation of scientific knowledge, algorithms, and technology to real-world sporting or clinical settings, and requires rigorous testing by multiple stakeholders. This process can take decades to have an influence on clinical practice. Validation is also a crucial part of translating technology and science into commercial application, although in this context validation needs to take into account usability, manufacturing, price/performance trade-offs, finding a product-market fit and determining your value proposition in the market place. This discussion will draw on the experience of a diverse panel to highlight some of the challenges of translating science to commercial applications. By illustrating through examples from the diverse and experienced panel members, various validation methods and their implications for commercialising a product or algorithm, compared with validating a hypothesis, will be covered

Changes in In Vivo Knee Contact Forces through Gait Modification

Gait modification represents a non-invasive method for reducing knee joint loading in patients with knee osteoarthritis. Previous studies have shown that a variety of gait modifications are effective in reducing the external knee adduction moment. The external knee adduction moment is often used as a surrogate measure of medial compartment force. However, a recent study showed that reductions in the external knee adduction moment do not guarantee reductions in medial compartment loads. Therefore, direct measurement of changes in knee contact force is important for determining the effectiveness of gait modifications. A previous study found that medial thrust gait and walking with hiking poles reduced contact force in a patient with a force-measuring knee replacement. The purpose of this study was to investigate the effects of additional gait modifications (mild crouch, moderate crouch, forefoot strike and bouncy gait) and four configurations of hiking poles on medial and lateral contact forces measured by a force-measuring knee replacement

Evaluation of Parallel Authentic Research-Based Courses in Human Biology on Student Experiences at Stanford University and the University of Gothenburg

Abstract: Under a previous grant (2005-08), researchers and teachers at Stanford University (SU) and the University of Gothenburg (GU) co-designed a ten-week interdisciplinary, research-based laboratory course in human biology to be taught online to undergraduate students. Essentials in the subject were taught during the first four weeks of this course. Subsequently, student groups at SU and GU developed their own research questions, conducted live-streamed experiments remotely, processed their unique data with support from multiple interactive resources, cross-cultural collaboration and an interdisciplinary network of expert consultants, and presented original scientific results remotely. Student course-perceptions were evaluated using online questionnaires, scientific logbooks, and observations. In student teams from both universities, the course concept clearly improved student abilities to conduct research using laboratory experiments while learning theoretical basics. A comparison of pre and post course scores from student surveys showed that post course student comfort levels with several research-related tasks increased radically at both universities. All participating staff generally agreed that the methods and tools were valuable in this type of course and should be evaluated at other levels and areas of higher education, and shared in an expanded network of universities.

Muscle Synergies Improve Estimation of Knee Contact Forces during Walking

This study investigates whether use of subject-specific muscle synergies can improve optimization predictions of muscle excitation patterns and knee contact forces during walking. Muscle synergies describe how a small number of neural commands generated by the nervous system can be linearly combined to produce the broad range of muscle electromyographic (EMG) signals measured experimentally. By quantifying the interdependence of individual EMG signals, muscle synergies provide dimensionality reduction for the neural control redundancy problem. Our hypothesis was that use of subjectspecific muscle synergies to limit muscle excitation patterns would improve prediction of muscle EMG patterns at the hip, knee, and ankle and of contact forces at the knee using a subject-specific lower body musculoskeletal computer model. The predictions were evaluated against in vivo experimental data collected from a subject implanted with a force-measuring tibial prosthesis

Synergies Controls Improve Prediction of Knee Contact Forces and Muscle Excitations during Gait

This study investigates whether use of muscle excitation controls constructed from subjectspecific muscle synergy information can improve optimization prediction of knee contact forces and muscle excitations during walking. Muscle synergies quantify how a large number of experimental muscle electromyographic (EMG) signals can be reconstructed by linearly mixing a much smaller number of neural commands generated by the nervous system. Our hypothesis was that controlling all muscle excitations with a small set of experimentally calculated neural commands would improve prediction of knee contact forces and leg muscle excitations compared to using independently controlled muscle excitations

Reproducibility in modeling and simulation of the knee:Academic, industry, and regulatory perspectives

Stakeholders in the modeling and simulation (M&amp;S) community organized a workshop at the 2019 Annual Meeting of the Orthopaedic Research Society (ORS) entitled “Reproducibility in Modeling and Simulation of the Knee: Academic, Industry, and Regulatory Perspectives.” The goal was to discuss efforts among these stakeholders to address irreproducibility in M&amp;S focusing on the knee joint. An academic representative from a leading orthopedic hospital in the United States described a multi-institutional, open effort funded by the National Institutes of Health to assess model reproducibility in computational knee biomechanics. A regulatory representative from the United States Food and Drug Administration indicated the necessity of standards for reproducibility to increase utility of M&amp;S in the regulatory setting. An industry representative from a major orthopedic implant company emphasized improving reproducibility by addressing indeterminacy in personalized modeling through sensitivity analyses, thereby enhancing preclinical evaluation of joint replacement technology. Thought leaders in the M&amp;S community stressed the importance of data sharing to minimize duplication of efforts. A survey comprised 103 attendees revealed strong support for the workshop and for increasing emphasis on computational modeling at future ORS meetings. Nearly all survey respondents (97%) considered reproducibility to be an important issue. Almost half of respondents (45%) tried and failed to reproduce the work of others. Two-thirds of respondents (67%) declared that individual laboratories are most responsible for ensuring reproducible research whereas 44% thought that journals are most responsible. Thought leaders and survey respondents emphasized that computational models must be reproducible and credible to advance knee M&amp;S.</p