The Slippery Slope Between Falling And Recovering: An Examination Of Sensory And Somatic Factors Influencing Recovery After A Slip

Background: Slips and falls account for large rates of injury and mortality in multiple populations. During an unexpected slip, sensory mechanisms are responsible for signaling the slip to the central nervous system, and a series of corrective responses is generated to arrest the slip and prevent a fall. While previous research has examined the corrective responses elicited, the answer of how these systems break down during a fall remains elusive. Purpose: To examine differences in postural control (slip detection), lower extremity corrective responses (slip recovery), and cortical control of the slip recovery response between individuals who fall and those who recover. Methods: One hundred participants were recruited for this study (50 males & 50 females). Participant’s gait kinematics and kinetics were collected during normal gait (NG) and an unexpected slip (US). The slip was classified as a fall or recovery, and by slip severity. Once classified, postural control, reaction times, corrective moments, and cortical contribution were examined between groups using ANOVAs and independent t-tests. Additionally, prediction equations for slip outcome, and slip severity were created using a binary logistic regression model. Slip Detection Results: Postural sway when the proprioceptive (OR = 0.02, CI: 0.01-1.34) and vestibular (OR = 0.60, CI: 0.26-1.39) systems are stressed were negatively associated with odds of falling. While postural sway when the visual system was stressed (OR = 3.18, CI: 0.887-11.445) was positively associated with odds of falling. Slip Recovery Results: Increased time to peak hip extension (OR = 1.006, CI: 1.00-1.01) and ankle dorsiflexion (OR = 1.005, CI: 1.00-1.01) moments increased the odds of falling. While the average ankle moment was negatively associated with falling (OR = 0.001, CI: 0.001-0.005). Cortical Contribution Results: Spectral power in the Piper frequency band was increased in US trials compared to NG. Further, fallers exhibited an increase in cortical activity compared to those who recovered. Conclusions: Rapid lower extremity corrective responses appear critical in arresting the slip and preventing a fall, and the temporal nature of this response may depend on slip detection and subsequent response selection. Moreover, our results suggest that more severe slips may require increased activation of higher centers of the motor cortex

The Influence of Casual Footwear on Human Balance

Falls are the third leading cause of unintentional death in homes and communities in the United States, causing 27,800 fatalities in 2012. The ability to maintain postural control is an essential part of activities of daily living (ADLs). However, recent types of casual footwear may be putting the body’s postural control system at a functional disadvantage, predisposing wearers to the risk of a fall. The purpose of this study was to examine the effects three forms of casual footwear (thong style flip-flops (FF), clog style Crocs® (CC), and Vibram® Five-Fingers (MIN)) have on postural control following a one mile walk at a preferred-pace. Eighteen healthy male adults (age: 22.9±2.8 years; height: 179±6.0 cm; mass: 81.3±8.8 kg) with no history of neuro-musculoskeletal disorders participated in this study. Static balance measures were recorded using eyes open (EO), eyes closed (EC), eyes open with sway referenced vision (EOSRV), and support, (EOSRP) conditions of the Sensory Organization Test (SOT). The average velocity (VEL) and root-mean-square (RMS) of the center of pressure (CoP) was used to quantify postural sway in the anterior-posterior (APVEL & APRMS) and medial-lateral (MLVEL & MLRMS) directions. Dynamic balance measures were recorded using the medium and large translations of the Motor Control Test (MCT). Muscle activity was collected at 1,500 Hz on the medial gastrocnemius (PF) and tibialis anterior (DF) using a Noraxon EMG system. Mean sway and EMG variables were analyzed using a 3x2 (footwear x time) repeated measures ANOVA. Footwear main effect significance was observed for APRMS in the EC condition (F2,34) = 7.914, p = 0.002), MLVEL (F(2,34) = 3.681, p = 0.036), and APVEL (F(2,34) = 7.469, p = 0.002) in the EOSRV condition with pairwise comparisons displaying increased instability in the CC and FF compared to MIN. Time main effect significance was seen for MLRMS in the EOSRV (F(1,17) = 6.532, p = 0.02) and EOSRP (F(1,17) = 8.982, p = 0.008) conditions with increased instability following the one-mile walk. Future research should seek to elucidate which combinations of these casual footwear characteristics are most detrimental to human balance

Persisting mobile phone use while driving and possible solutions for New Zealand

In New Zealand the use of hand-held phones while driving was prohibited in 2009, but ‘hands-free’ phones are still permitted. We recently presented the results of an observational study into mobile phone among Wellington drivers at a conference (for details see the proceedings). The main findings were that out of 8335 cars systematically observed at traffic lights and 9520 cars in moving traffic (each at three different Wellington locations), the use of mobile phones was 1.87% (95%CI: 1.60-2.18) and 1.34% (95%CI: 1.13-1.59) respectively

Educational trips and resource visitors available to the central school in the town of Colchester, Connecticut

Thesis (Ed.M.)--Boston Universit

Estimating Under Five Mortality in Space and Time in a Developing World Context

Accurate estimates of the under-5 mortality rate (U5MR) in a developing world context are a key barometer of the health of a nation. This paper describes new models to analyze survey data on mortality in this context. We are interested in both spatial and temporal description, that is, wishing to estimate U5MR across regions and years, and to investigate the association between the U5MR and spatially-varying covariate surfaces. We illustrate the methodology by producing yearly estimates for subnational areas in Kenya over the period 1980 - 2014 using data from demographic health surveys (DHS). We use a binomial likelihood with fixed effects for the urban/rural stratification to account for the complex survey design. We carry out smoothing using Bayesian hierarchical models with continuous spatial and temporally discrete components. A key component of the model is an offset to adjust for bias due to the effects of HIV epidemics. Substantively, there has been a sharp decline in U5MR in the period 1980 - 2014, but large variability in estimated subnational rates remains. A priority for future research is understanding this variability. Temperature, precipitation and a measure of malaria infection prevalence were candidates for inclusion in the covariate model.Comment: 36 pages, 11 figure

Language and Cooperation in Hominin Scavenging

Bickerton (2009, 2014) hypothesizes that language emerged as the solution to a scavenging problem faced by proto‐humans. We design a virtual world to explore how people use words to persuade others to work together for a common end. By gradually reducing the vocabularies that the participants can use, we trace the process of solving the hominin scavenging problem. Our experiment changes the way we think about social dilemmas. Instead of asking how does a group overcome the selfinterest of its constituents, the question becomes, how do constituents persuade one another to work together for a common end that yields a common benefit

The semiquinone radical anion of 1,10-phenanthroline-5,6-dione: synthesis and rare earth coordination chemistry

Reduction of 1,10-phenanthroline-5,6-dione (pd) with CoCpR2 resulted in the first molecular compounds of the pd˙− semi-quinone radical anion, [CoCpR2]+[pd]˙− (R = H, (1); R = Me4, (2)). Furthermore compounds 1 and 2 were reacted with [Y(hfac)3(thf)2] (hfac = 1,1,1-5,5,5-hexafluoroacetylacetonate) to synthesise the rare earth-transition metal heterometallic compounds, [CoCpR2]+[Y(hfac)3(N,N′-pd)]˙− (R = H, (3); R = Me4, (4))

Quiet Eye Training Facilitates Competitive Putting Performance in Elite Golfers

The aim of this study was to examine the effectiveness of a brief quiet eye (QE) training intervention aimed at optimizing visuomotor control and putting performance of elite golfers under pressure, and in real competition. Twenty-two elite golfers (mean handicap 2.7) recorded putting statistics over 10 rounds of competitive golf before attending training individually. Having been randomly assigned to either a QE training or Control group, participants were fitted with an Applied Science Laboratories Mobile Eye tracker and performed 20 baseline (pre-test) putts from 10 ft. Training consisted of video feedback of their gaze behavior while they completed 20 putts; however the QE-trained group received additional instructions related to maintaining a longer QE period. Participants then recorded their putting statistics over a further 10 competitive rounds and re-visited the laboratory for retention and pressure tests of their visuomotor control and putting performance. Overall, the results were supportive of the efficacy of the QE training intervention. QE duration predicted 43% of the variance in putting performance, underlying its critical role in the visuomotor control of putting. The QE-trained group maintained their optimal QE under pressure conditions, whereas the Control group experienced reductions in QE when anxious, with subsequent effects on performance. Although their performance was similar in the pre-test, the QE-trained group holed more putts and left the ball closer to the hole on missed putts than their Control group counterparts in the pressure test. Importantly, these advantages transferred to the golf course, where QE-trained golfers made 1.9 fewer putts per round, compared to pre-training, whereas the Control group showed no change in their putting statistics. These results reveal that QE training, incorporated into a pre-shot routine, is an effective intervention to help golfers maintain control when anxious

Anxiety, Attentional Control, and Performance Impairment in Penalty Kicks

© 2009 Human Kinetics, IncThe current study sought to test the predictions of attentional control theory (ACT) in a sporting environment. Fourteen experienced footballers took penalty kicks under low- and high-threat counterbalanced conditions while wearing a gaze registration system. Fixations to target locations (goalkeeper and goal area) were determined using frame-by-frame analysis. When anxious, footballers made faster first fixations and fixated for significantly longer toward the goalkeeper. This disruption in gaze behavior brought about significant reductions in shooting accuracy, with shots becoming significantly centralized and within the goalkeeper’s reach. These findings support the predictions of ACT, as anxious participants were more likely to focus on the “threatening” goalkeeper, owing to an increased influence of the stimulus-driven attentional control system

The influence of anxiety on visual attentional control in basketball free throw shooting.

addresses: School of Sport and Health Sciences, University of Exeter, St. Luke's Campus, Exeter, U.K.types: Journal Article© 2009 Human Kinetics, IncThe aim of this study was to test the predictions of attentional control theory using the quiet eye period as an objective measure of attentional control. Ten basketball players took free throws in two counterbalanced experimental conditions designed to manipulate the anxiety they experienced. Point of gaze was measured using an ASL Mobile Eye tracker and fixations including the quiet eye were determined using frame-by-frame analysis. The manipulation of anxiety resulted in significant reductions in the duration of the quiet eye period and free throw success rate, thus supporting the predictions of attentional control theory. Anxiety impaired goal-directed attentional control (quiet eye period) at the expense of stimulus-driven control (more fixations of shorter duration to various targets). The findings suggest that attentional control theory may be a useful theoretical framework for examining the relationship between anxiety and performance in visuomotor sport skills