The Use, Integration and Perceived Value of Performance Analysis in a Broad Population of Coaches

Research into the perceptions, practices and engagement of coaches with performance analysis is fundamental to informing the continued development of the discipline and its practitioners. The aim of this study was to survey a large sample of coaches of varying profiles, regarding their use and integration of performance analysis, to explore its perceived value and barriers to its use. Survey data were analysed from 538 Irish coaches qualified at Level 1 and above (82% male), from 37 sports. A spectrum of coaches’ engagement with performance analysis, ranging from no formal performance analysis (49%), to coaches doing their own analysis (coach-as-analyst, 38%) and coaches with analystsupport (13%) was observed. The Level 2 coaching qualification was a key distinguisher between coaches using and not using performance analysis. Significant differences exist between the practices of coaches with and without analystsupport. Coaches with analyst-support are more likely to have regular access to video, spend more time analysing, regularly use performance analysis to inform training and use computerised analysis software. Barriers to the use of performance analysis varied along the spectrum of performance analysis engagement. This research can underpin future developments in coach and analyst education that will optimise the systematic use of PA across all levels of sports performance

The use, integration and perceived value of performance analysis to professional and amateur Irish coaches

Research into the perceptions, practices and engagement of coaches with performance analysis is fundamental to informing the continued development of the discipline and its practitioners. The aim of this study was to survey a large sample of coaches of varying profiles, regarding their use and integration of performance analysis, to explore its perceived value and barriers to its use. Survey data were analysed from 538 Irish coaches qualified at Level 1 and above (82% male), from 37 sports. A spectrum of coaches’ engagement with performance analysis, ranging from no formal performance analysis (49%), to coaches doing their own analysis (coach-as-analyst, 38%) and coaches with analystsupport (13%) was observed. The Level 2 coaching qualification was a key distinguisher between coaches using and not using performance analysis. Significant differences exist between the practices of coaches with and without analystsupport. Coaches with analyst-support are more likely to have regular access to video, spend more time analysing, regularly use performance analysis to inform training and use computerised analysis software. Barriers to the use of performance analysis varied along the spectrum of performance analysis engagement. This research can underpin future developments in coach and analyst education that will optimise the systematic use of PA across all levels of sports performance

The influence of auditory-motor coupling on fractal dynamics in human gait

Humans exhibit an innate ability to synchronize their movements to music. The field of gait rehabilitation has sought to capitalize on this phenomenon by invoking patients to walk in time to rhythmic auditory cues with a view to improving pathological gait. However, the temporal structure of the auditory cue, and hence the temporal structure of the target behavior has not been sufficiently explored. This study reveals the plasticity of auditory-motor coupling in human walking in relation to ‘complex’ auditory cues. The authors demonstrate that auditory-motor coupling can be driven by different coloured auditory noise signals (e.g. white, brown), shifting the fractal temporal structure of gait dynamics towards the statistical properties of the signals used. This adaptive capability observed in whole-body movement, could potentially be harnessed for targeted neuromuscular rehabilitation in patient groups, depending on the specific treatment goal

Developing A Framework For Professional Practice In Applied Performance Analysis

Applied performance analysts are increasingly seen as sports science professionals; however, there is no accepted framework for professional practice. The purpose of this study is to develop and validate a framework for professional practice in applied performance analysis (PA) which identifies the components of practice and the expertise underpinning it. A six-step framework analysis was conducted: (1) An initial conceptual framework was devised based on well-accepted components of applied practice; (2) A systematic review identified 90 papers relating to applied PA practice; (3) Papers were coded to the initial framework and additional themes recorded; (4) Themes were analysed and synthesised to construct a draft framework; (5) This draft was validated by surveying 24 experienced applied performance analysts and academic experts; (6) A revised framework is reported based on stakeholder engagement feedback. Nine components of practice were identified; establishing relationships and defining roles, needs analysis and service planning, system design, data collection and reliability checking, data management, analysis, reporting to key stakeholders, facilitation of feedback to athletes and service review and evaluation. Our evidence suggests that applied PA practice is underpinned by five areas of expertise: contextual awareness, building relationships, performance analysis and sporting expertise, technical expertise and professional behaviour

Human Movement Variability and Aging

An optimal level of variability enables us to interact adaptively and safely to a continuously changing environment, where often our movements must be adjusted in a matter of milliseconds. A large body of research exists that demonstrates natural variability in healthy gait (along with variability in other, healthy biological signals such as heart rate) and a loss of this variability in aging and injury, as well as in a variety of neurodegenerative and physiological disorders. We submit that this field of research is now in pressing need of an innovative “next step” that goes beyond the many descriptive studies that characterize levels of variability in various patient populations. We need to devise novel therapies that will harness the existing knowledge on biological variability and create new possibilities for those in the grip of disease. We also propose that the nature of the specific physiological limitation present in the neuromuscular apparatus may be less important in the physiological complexity framework than the control mechanisms adopted by the older individual in the coordination of the available degrees of freedom. The theoretical underpinnings of this framework suggest that interventions designed to restore healthy system dynamics may optimize functional improvements in older adults. We submit that interventions based on the restoration of optimal variability and movement complexity could potentially be applied across a range of diseases or dysfunctions as it addresses the adaptability and coordination of available degrees of freedom, regardless of the internal constraints of the individual

Gait variablility is altered in older adults when listening to auditory stimuli with differing temporal structures

Gait variability in the context of a deterministic dynamical system may be quantified using nonlinear time series analyses that characterize the complexity of the system. Pathological gait exhibits altered gait variability. It can be either too periodic and predictable, or too random and disordered, as it is the case with aging. While gait therapies often focus on restoration of linear measures such as gait speed or stride length, we propose that the goal of gait therapy should be to restore optimal gait variability, which exhibits chaotic fluctuations and is the balance between predictability and complexity. In this context, our purpose was to investigate how listening to different auditory stimuli affects gait variability. Twenty-seven young and 27 elderly subjects walked on a treadmill for 5 minutes while listening to white noise, a chaotic rhythm, a metronome, and with no auditory stimulus. Stride length, step width, and stride intervals were calculated for all conditions. Detrended Fluctuation Analysis was then performed on these time series. A quadratic trend analysis determined that an idealized inverted-U shape described the relationship between gait variability and the structure of the auditory stimuli for the elderly group, but not for the young group. This proof-of-concept study shows that the gait of older adults may be manipulated using auditory stimuli. Future work will investigate which structures of auditory stimuli lead to improvements in functional status in older adults

The use, integration and value of performance analysis to GAA coaches

Performance analysis (PA) has become integral to the multi-million euro preparation of intercounty GAA teams (GAA, 2013). With little research on the coaching practice of GAA coaches, this paper explores their engagement with PA. Its aims were to examine the use, integration and value of PA to coaches. A sample of 12,500 (minimum level 1 Coaching Ireland qualified) coaches were selected to complete an online-survey with 538 respondents across 37 sports. As the highest responding cohort (n=144), data for the GAA coaches was isolated for further analysis. PA was used by 49% of GAA coaches. These coaches were more likely to have 10+ years coaching experience (Xi2 = 20.7 p = 0); be qualified beyond GAA Award 1 (Xi2 = 14.0 p = 0) and coach at intercounty level (Xi2 = 12.3 p = 0). Coaches using PA had access primarily to match statistics (81%); only 49% had access to match video. The most popular tools for data collection were hand notation (65%), Dartfish (38%) and Apps (38%). Coaches cited resources and knowledge as key barriers to progressing their use of PA. Reliability of information was not identified as an issue. 88% of coaches using PA felt it was important / essential to their practice. The findings indicate that GAA coaches have substantially more access to quantitative information compared to video feedback. This lack of video to contextualise and validate data has potential to hamper the interpretation of information by a coach thus impacting their subsequent interventions. In GAA coach education, more emphasis could be placed on the importance of contextualising statistics with video and the potential of video feedback to players. Coaches should be encouraged to question the reliability of match statistics and equipped with appropriate strategies to minimise errors in data collection

Peripheral Arterial Disease Affects the Frequency Response of Ground Reaction Forces During Walking

Background—Walking is problematic for patients with Peripheral Arterial Disease. The purpose of this study was to investigate the frequency domain of the ground reaction forces during walking to further elucidate the ambulatory impairment of these patients. Methods—Nineteen bilateral peripheral arterial disease patients and nineteen controls were included in this study. Subjects were matched for age and gait speed. Participants walked over a force plate sampling at 600Hz. PAD patients were tested before (pain-free condition) after the onset of claudication symptoms (pain). We calculated median frequency, frequency bandwidth, and frequency containing 99.5% of the signal for the vertical and anterior-posterior ground reaction forces. Findings—Our results showed reduced median frequency in the vertical and anterior-posterior components of the ground reaction forces between the control group and both peripheral arterial disease conditions. We found reduced frequency bandwidth in the anterior-posterior direction between controls and the peripheral arterial disease pain-free condition. There were no differences in median frequency or bandwidth between peripheral arterial disease pain-free and pain conditions, but an increase in the frequency content for 99.5% of the signal was observed in the pain condition. Interpretation—Reduced frequency phenomena during gait in peripheral arterial disease patients compared to velocity-matched controls suggests more sluggish activity within the neuromotor system. Increased frequency phenomena due to pain in these patients suggests a more erratic application of propulsive forces when walking. Frequency domain analysis thus offers new insights into the gait impairments associated with this patient population

The Appropriate Use of Approximate Entropy and Sample Entropy with Short Data Sets

Approximate entropy (ApEn) and sample entropy (SampEn) are mathematical algorithms created to measure the repeatability or predictability within a time series. Both algorithms are extremely sensitive to their input parameters: m (length of the data segment being compared), r (similarity criterion), and N (length of data). There is no established consensus on parameter selection in short data sets, especially for biological data. Therefore, the purpose of this research was to examine the robustness of these two entropy algorithms by exploring the effect of changing parameter values on short data sets. Data with known theoretical entropy qualities as well as experimental data from both healthy young and older adults was utilized. Our results demonstrate that both ApEn and SampEn are extremely sensitive to parameter choices, especially for very short data sets, N ≤ 200. We suggest using N larger than 200, an m of 2 and examine several r values before selecting your parameters. Extreme caution should be used when choosing parameters for experimental studies with both algorithms. Based on our current findings, it appears that SampEn is more reliable for short data sets. SampEn was less sensitive to changes in data length and demonstrated fewer problems with relative consistency

Experimental Analyses of Step Extent and Contact Buffer in Pedestrian Dynamics

This study aims to quantify and develop a deeper understanding of the parameters that underpin the development of a new, predictive, microscopic model of pedestrian movement with the potential to accurately reflect the complexity of flow dynamics now and into the future. It presents the results and analyses of two single file experiments designed to quantify the physical space taken up by the extent of a person's stepping movement (maximum step extent) and the minimum distance between points of inter-person contact (contact buffer) across a range of walking speeds. The experiments successfully used high-resolution optical motion capture and enhanced video analysis to quantify the dynamic changes in gait and spatial parameters, which were manifested as overlapping steps, and changes to step extent, step length, step frequency, and contact distance. The sum of the step extent and contact buffer, at different speeds, was found to be within a few centimetres of the inter-person distance (headway), leading to the conclusion that these parameters are therefore key components for the derivation of inter-person spacing and, hence, overall crowd movement. The work informs the longer term aim of developing the mathematical model which has the potential to include pedestrian demographics, walking ability and cognitive capabilities