ECSS Paris 2023: OP-AP39
INTRODUCTION: Successful skill execution in high-velocity interceptive sports requires transforming visual information into action within severe temporal constraints. Skilled actions are typically attributed to conscious visual processing and motor planning through cortical pathways. However, laboratory-based reaching studies reveal a phylogenetically preserved fast-response system operating via subcortical structures that generates inflexibly time-locked express visuomotor responses (eVMR)—eye movements and premotor muscle bursts from ~70ms after target onset (1-4). Kinematic movement appears driven not by these early responses but by a subsequent burst of cortically generated muscle activity, leaving the functional role of the subcortical pathway unclear. We therefore asked whether eVMR contribute meaningfully to performance in ecologically valid, time-critical, real-world tasks. To test this, we developed a ball-catching paradigm inspired by slip-catching in cricket. METHODS: Twenty skilled cricketers performed a catching task with tennis balls propelled from two laterally positioned ball machines set behind an occluding screen (Ball velocity ~46km/h, reaction time window 300-320ms). We recorded eye movements (EOG), upper-limb kinematics (accelerometer), and muscle activity (surface EMG) of the pectoralis major and posterior deltoid. Ball presentation time was determined by infrared sensors and a microphone. RESULTS: Robust express responses (~65-95ms) were observed on most trials with limb kinematic movement initiated within 100ms of target presentation in a substantial subset of trials (error rates <3% dismissing anticipatory strategies). This markedly exceeds computer-based reach tasks findings where eVMR are detected in the pectoralis major and posterior deltoid on only 59% and 54% of trials respectively (4), and reaction time <130ms classified as anticipatory (3) or as outliers (1,2). Together, this indicates that the subcortical pathway is functioning to facilitate movement in high-velocity catching. CONCLUSION: This study provides new evidence that limb movements are meaningfully initiated by the first subcortical wave of muscle activity that occurs prior to cortical visuomotor processing in a real-world sporting task. Understanding the mechanism underlying rapid reaction capabilities and how to engage it has potential applications for: (1) talent identification using neurophysiological markers; (2) informed targeted junior development; (3) monitoring athlete readiness and fatigue through response latency tracking; and (4) developing perceptual-motor training interventions that engage subcortical pathways. Furthermore, this paradigm translates to other sports/skills (e.g. racquet sports, goalkeeping, and combat) where rapid target detection and response are performance-critical. References: 1. Pruszynski et al. (2010). 2. Gu et al. (2016). 3. Contemori et al. (2021). 4. Contemori et al. (2022).
Read CV Adam BoddyECSS Paris 2023: OP-AP39
INTRODUCTION: Enhanced autonomic nervous system (ANS) function is linked to superior athletic performance, commonly indexed via heart rate variability (HRV).1 However, HRV provides limited ability to distinguish parasympathetic (PNS) from sympathetic (SNS) activity.2 The pupil light reflex (PLR) may offer an alternative, providing independent measures of PNS and SNS activity.3 No studies have examined whether PLR-derived resting ANS profiles predict functional performance. Characterising this relationship may offer a rapid, non-invasive tool for monitoring movement readiness or early physiological dysfunction. The aim of this study was to investigate whether resting ANS profiles, indexed through the PLR, are associated with performance on standardised functional movement assessments. METHODS: 90 healthy, physically active adults (age 20–88) participated. ANS activity was measured using the PLR: PNS function via maximum pupil constriction velocity and SNS function via average pupil dilation velocity. Using z scores derived from published normative PLR data, participants were categorised into one of four resting ANS profiles: Coactivation, Co inhibition, PNS dominant, or SNS dominant. Participants then completed Timed Up and Go (TUG), Six Minute Walk Test (6MWT) and Five Times Sit to Stand (5xSTS). One way ANOVAs (Jamovi v2.7.12) with Tukey post hoc comparisons examined differences across ANS profiles for each functional outcome measure. Complimentary Bayesian analyses were performed given unequal group sizes. Statistical significance set at p<0.05. RESULTS: Across the sample (Co-inhibition n=9; Coactivation n=35; PNS-dominant n=26; SNS-dominant n = 20), the Co-inhibition profile was associated with poorer functional performance. Co-inhibition participants demonstrated significantly slower TUG times compared to with coactivation (mean difference=1.12s, p=0.05, BF₁₀=8.39). For 6MWT, Co-inhibition participants walked significantly shorter distances than Coactivation profile (mean difference=-108m; p<0.01; BF₁₀=16.05) and PNS-dominant profile (mean difference = -89 m; p=0.05; BF₁₀=10.35). For 5xSTS, Co-inhibition was slower than Coactivation (mean difference=2.14s; p=0.08; BF₁₀=2.07), although this did not reach statistical significance. CONCLUSION: The results demonstrate a performance deficit in the Co inhibition profile across three standardised functional tests, thus inhibition in both branches of the ANS system at rest may be a limiting factor in functional performance. Measuring ANS balance via the PLR could reveal obscured underlying factors contributing to performance deficits. Limitations include unequal group sizes, reflecting the natural distribution of ANS profiles, which precluded an a priori power calculation. Although the Co-inhibition group was older on average, older adults were present in other ANS profiles, indicating that age alone is unlikely to explain the observed differences. References: 1. Bellenger et al. (2016); 2. Hayano & Yuda (2019); 3. Mathôt (2018).
Read CV Michaela McGrathECSS Paris 2023: OP-AP39
INTRODUCTION: Visuomotor reaction time (VMRT) is a critical determinant of sport performance, particularly in disciplines requiring rapid decision-making under dynamic conditions. Stroboscopic visual training (SVT) aims to enhance visual information processing; however, evidence combining SVT with interactive light stimuli and involving both upper and lower limbs across different sport typologies remains limited. The aim of this study was to investigate the responses under different tasks combined with interactive light stimuli and wearing stroboscopic glasses (SG), on manual and podal reaction time (RT), dividing participants in two groups: individual and team sports. METHODS: 23 athletes (24.65 ± 4.80, years) were assigned by to group: individual (ISG, n° = 14) and team sport group (TSG, n° = 15). Participants performed simple (SRT), recognition (RRT), and choice reaction time (CRT) tasks using a BlazePod system with both limbs. Both group performed three tasks (T0, T1, T2) without SG and three wearing SG. RESULTS: Comparing T0 and T2 the ISG, obtain fastest responses in all parameters: SRTM −112 ms (−16.9%), RRTM −92 ms (−13.0%), CRTM −57 ms (−6.8%), with the largest gains in simple reaction tasks. The TSG, obtain better responses mainly in simple reaction tasks (SRTM −85 ms) while recognition and choice tasks remained stable. At T0, ISG was slower than TSG across all parameters; at T2, ISG remained slower in complex tasks, while choice reaction with hands (CRTM) not showed statistical differences. In addition, a RM ANOVA was conducted and results showed that TSG showed faster RT in complex tasks (RRT and CRT) with hands (RRTM, 0.041, RRTT 0.014; CRTM 0.013, CRTT 0.019), and also with feet (RRTM 0.032, RRTT 0.050) though less pronounced. CONCLUSION: Interactive light-based training evidence in VMRT responses in both groups. SVT does not induce superior short-term gains but accentuate sport-specific adaptations, especially in complex reaction tasks. These findings highlight the critical need to tailor SVT based on sport type to maximize performance benefits.
Read CV Giada D AlessandroECSS Paris 2023: OP-AP39