Comparing inertial measurement units and marker-based biomechanical models during dynamic rotation of the torso

Inertial measurement units (IMUs) enable human movements to be captured in the field and are being used increasingly in high performance sport. One key metric that can be derived from IMUs are relative angles of body segments which are important for monitoring form in many sports. The purpose of this study was to a) examine the validity of relative angles derived from IMUs placed on the torso and pelvis; and b) determine optimal positioning for torso mounted sensors such that the IMU relative angles match closely with gold standard torso-pelvis and thorax-pelvis relative angle data derived from an optoelectronic camera system. Seventeen adult participants undertook a variety of motion tasks. Four IMUs were positioned on the torso and one was positioned on the pelvis between the posterior superior iliac spines. Reflective markers were positioned around each IMU and over torso and pelvis landmarks. Results showed that the IMUs are valid with the root mean square errors expressed as a percentage of the angle range (RMSE%) ranging between 1% and 7%. Comparison between the IMU relative angles and the torso-pelvis and thorax-pelvis relative angles showed there were moderate to large differences with RMSE% values ranging between 4% and 57%. IMUs are highly accurate at measuring orientation data; however, further work is needed to optimize positioning and modelling approaches so IMU relative angles align more closely with relative angles derived using traditional motion capture methods

The validity of using inertial measurement units to monitor the torso and pelvis sagittal plane motion of elite rowers

In elite sport, inertial measurement units (IMUs) are being used increasingly to measure movement in-field. IMU data commonly sought are body segment angles as this gives insights into how technique can be altered to improve performance and reduce injury risk. The purpose of this was to assess the validity of IMU use in rowing and identify if IMUs are capable of detecting differences in sagittal torso and pelvis angles that result from changes in stroke rates. Eight elite female rowers participated. Four IMUs were positioned along the torso and over the pelvis of each athlete. Reflective markers surrounded each IMU which were used to compute gold-standard data. Maxima, minima, angle range and waveforms for ten strokes at rates of 20, 24, 28 and 32 strokes per minute were analysed. Root mean square errors as a percentage of angle range fell between 1.44% and 8.43%. In most cases when significant differences (p < 0.05) in the angles were detected between stroke rates, this was observed in both IMU and gold-standard angle data. These findings suggest that IMUs are valid for measuring torso and pelvis angles when rowing and are capable of detecting differences that result from changes in stroke rate

Ironies of proximity: Intergroup threat and contact avoidance on neighbourhood interface areas

Research on the dynamics of neighbourhood desegregation and diversity has identified a paradox. On the one hand, such processes may engender positive intergroup contact experiences, improving intergroup attitudes and relations. On the other hand, they may have the opposite effect, exacerbating negative intergroup relations and generating new forms of avoidance and exclusion. The present research explored one aspect of this paradox. Building on a field survey conducted with Indian residents (n = 364) of a suburb of Pietermaritzburg, South Africa, we demonstrate how their relative proximity to areas occupied by ‘incoming’ Black African residents has shaped their perceptions of intergroup threat and associated reactions such as contact avoidance, boundary fortification and support for policies resisting desegregation. At the same time, we demonstrate how such effects are moderated by residents' wider experiences of positive interracial contact. In conclusion, we emphasize the need to better integrate psychological work on the contact hypothesis with work in companion disciplines such as urban studies and human geography. Please refer to the Supplementary Material section to find this article's Community and Social Impact Statement

Genetic screening for cystic fibrosis: An overview of the science and the economics

AbstractThe aim of this paper is to provide an overview of the current scientific and economic thinking on the use of genetic technologies for cystic fibrosis (CF) screening. The paper takes a public health genetics viewpoint and gives an overview of the genetics behind CF, then describes current practices in screening for the disease. We then discuss the current literature on the economic evaluations of screening for CF. As the “wet” science improves, there are direct implications for health service. Therefore, it is important to keep examining both clinical practice and economics behind the technologies