The ergonomics of wheelchair configuration for optimal sport performance

The ergonomics of wheelchair configuration for optimal sport performanc

Troubleshooting and rectifying structural mechanics problems –- applied mechanics in industry

This paper outlines the general process of troubleshooting and rectifying unexpected structural mechanics problems in industrial plant and infrastructure. Typically the process includes the combination and correlation of site measurements (strain, vibration), and computational simulations (finite element analysis, computational fluid dynamics) to identify root cause sources and guide redesign and rectification means. Details of typical site installations are outlined, including mining machinery, gas pipelines, railway lines, manufacturing plant and ships. Four case studies are included, ranging from resin manufacturing tubular agitators suffering vortex induced resonance, ore grinding mills needing better access manhole design, mine dump trucks, and ship shafting issues

Combined Computational and Intracellular Peptide Library Screening: Towards a Potent and Selective Fra1 Inhibitor

To date, most research into the inhibition of oncogenic transcriptional regulator, Activator Protein 1 (AP-1), has focused on heterodimers of cJun and cFos. However, the Fra1 homologue remains an important cancer target. Here we describe library design coupled with computational and intracellular screening as an effective methodology to derive an antagonist that is selective for Fra1 relative to Jun counterparts. To do so the isCAN computational tool was used to rapidly screen >75 million peptide library members, narrowing the library size by >99.8% to one accessible to intracellular PCA selection. The resulting 131,072-member library was predicted to contain high quality binders with both a high likelihood of target engagement, while simultaneously avoiding homodimerization and off-target interaction with Jun homologues. PCA screening was next performed to enrich those members that meet these criteria. In particular, optimization was achieved via inclusion of options designed to generate the potential for compromised intermolecular contacts in both desired and non-desired species. This is an often-overlooked prerequisite in the conflicting design requirement of libraries that must be selective for their target in the context of a range of alternative potential interactions. Here we demonstrate that specificity is achieved via a combination of both hydrophobic and electrostatic contacts as exhibited by the selected peptide (Fra1W). In vitro analysis of the desired Fra1-Fra1W interaction further validates high Fra1 affinity (917 nM) yet selective binding relative to Fra1W homodimers or affinity for cJun. The isCANPCA based multidisciplinary approach provides a robust screening pipeline in generating target-specific hits, as well as new insight into rational peptide design in the search for novel bZIP family inhibitors

Expert users’ perceptions of racing wheelchair design and set up: The knowns, unknowns and next steps

This paper demonstrates how a qualitative methodology can be used to gain novel insights into the demands of wheelchair racing and the impact of particular racing chair configurations on optimal sport performance via engagement with expert users (wheelchair racers, coaches and manufacturers). We specifically explore how expert users understand how wheels, tires and bearings impact upon sport performance and how they engage, implement or reject evidence-based research pertaining to these components. We identify areas where participants perceive there to be an immediate need for more research especially pertaining to the ability to make individualized recommendations for athletes. The findings from this project speak to the value of a qualitative research design for capturing the embodied knowledge of expert users and also make suggestions for ‘next step’ projects pertaining to wheels, tires and bearings drawn directly from the comments of participants

Brake assembly bench part set up and part presentation

In partnership with Meritor, this project focused on improving the part presentation and downtime losses of the current brake assembly process. The way in which the parts are currently presented to an operator causes an ergonomic strain on the worker, which is not ideal for production, resulting in worker downtime losses and an inefficient build rate. The Rapid Upper Limb Assessment (RULA) was conducted to ensure the ergonomic strain on the worker remains at an acceptable level. As a result of performing two fishbone diagrams on the downtime and ergonomic strain, the team quantified the system losses by the amount of time lost and quantified harmful motions by conducting a RULA assessment. Based on the findings of the Pareto chart and utilizing various Industrial Engineering tools, the team was able to provide solutions to reduce the amount of downtime while also ensuring the motions of workers remain ergonomically safe

SPEED PROFILES IN WHEELCHAIR COURT SPORTS; COMPARISON OF TWO METHODS FOR MEASURING WHEELCHAIR MOBILITY PERFORMANCE

Wheelchair mobility performance is an important aspect in most wheelchair court sports, commonly measured with an indoor tracking system or wheelchair bound inertial sensors. Both methods provide key performance outcomes regarding speed. In this study, we compared speed profiles of both methods to gain insight in the level of agreement. Data were obtained from 5 players during 6x 10 min. of wheelchair basketball match play. Both systems provide similar outcomes regarding distance covered and average speed. Due to differences in sample frequency and reference position on the wheelchair (for speed calculation), minor differences show at low speeds (\u3c2.5 m/s). Since both systems provide complementary features, a hybrid solution as proved feasible in this study, could possibly serve as the new standard for mobility performance measurement in court sports

The physiological and biomechanical effects of forwards and reverse sports wheelchair propulsion

Objective To explore the physiological and biomechanical differences between forwards (FOR) and reverse (REV) sports wheelchair propulsion. Design Fourteen able-bodied males with previous wheelchair propulsion experience pushed a sports wheelchair on a single-roller ergometer in a FOR and REV direction at three sub-maximal speeds (4, 6, and 8 km/hour). Each trial lasted 3 minutes, and during the final minute physiological and biomechanical measures was collected. Results The physiological results revealed that oxygen uptake (1.51 ± 0.29 vs. 1.38 ± 0.26 L/minute, P = 0.005) and heart rate (121 ± 19 vs. 109 ± 14 beats/minute, P 0.05). However, greater mean resultant forces were applied during FOR (P < 0.0005) at 4 km/hour (66.7 ± 19.5 vs. 49.2 ± 10.3 N), 6 km/hour (90.7 ± 21.9 vs. 65.3 ± 18.6 N), and 8 km/hour (102.5 ± 17.6 vs. 68.7 ± 13.5 N) compared to REV. Alternatively, push times and push angles were significantly lower (P ≤ 0.001) during FOR at each speed. Conclusions The current study demonstrated that at higher speeds physiological demand becomes elevated during REV. This was likely to be associated with an inability to apply sufficient force to the wheels, thus requiring kinematic adaptations in order to maintain constant speeds in REV

Validity and reliability of an inertial sensor for wheelchair court sports performance

The purpose of the current study was to determine the validity and reliability of an inertial sensor for assessing speed specific to athletes competing in the wheelchair court sports (basketball, rugby, and tennis). A wireless inertial sensor was attached to the axle of a sports wheelchair. Over two separate sessions, the sensor was tested across a range of treadmill speeds reflective of the court sports (1.0 to 6.0 m/s). At each test speed, ten 10-second trials were recorded and were compared with the treadmill (criterion). A further session explored the dynamic validity and reliability of the sensor during a sprinting task on a wheelchair ergometer compared with high-speed video (criterion). During session one, the sensor marginally overestimated speed, whereas during session two these speeds were underestimated slightly. However, systematic bias and absolute random errors never exceeded 0.058 m/s and 0.086 m/s, respectively, across both sessions. The sensor was also shown to be a reliable device with coefficients of variation (% CV) never exceeding 0.9 at any speed. During maximal sprinting, the sensor also provided a valid representation of the peak speeds reached (1.6% CV). Slight random errors in timing led to larger random errors in the detection of deceleration values. The results of this investigation have demonstrated that an inertial sensor developed for sports wheelchair applications provided a valid and reliable assessment of the speeds typically experienced by wheelchair athletes. As such, this device will be a valuable monitoring tool for assessing aspects of linear wheelchair performance