Physiotherapy
Permanent URI for this collectionhttps://eresearch.qmu.ac.uk/handle/20.500.12289/7190
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Item Sensorimotor and neuromuscular performance capabilities in elite young soccer players(2021) Clancy, ColinFollowing a review of the literature and using a prospective observational design delivered in an ecologically valid setting, this thesis enhances knowledge of sensorimotor (SM) and neuromuscular (NM) performance capabilities in elite young soccer players, culminating with a controlled cohort study to further investigate the influence of high intensity exercise stress on performance capabilities. Alterations in player perceived capabilities using the Borg Category-Ratio Scale (CR-10) and Perceived percentage of completed task duration (PTD), were also investigated. Impaired NM performance as a symptom of fatigue has previously been demonstrated in elite soccer players. However, the results from outcome measures offering such detailed and granular biological insights have not been documented previously. In addition, this research project aimed to observe (Chapter 6) and then provoke (Chapter 7) turbulence, physiologically, to examine whether the SM system is similarly affected, thereby verifying this mechanism as operational for soccer players. To objectify the conditioning dosage to which elite young soccer players are typically exposed to, Chapter 3 offered a season-long patterning of training and match-workload. To further contextualise the backdrop of this research project, NM performance capabilities were benchmarked by comparison with senior professional players in Chapter 4. Performance capabilities of sixteen elite male soccer players (age: 19.2 ± 1.1 years; height: 183.3 ± 6.1 cm; body mass: 76.1 ± 7.8 kg) were evaluated at weekly intervals over a 6-week in-season mesocycle (Chapter 5), and daily during a weekly competitive microcycle (Chapter 6). Assessments of peak twitch force (PTFe) and electromechanical delay (EMD) demonstrated significant changes in NM performance capability (p < 0.05; 13.6% and 15.1% impairments, respectively) whereas SM performance capability was preserved (p > 0.05). Congruence amongst fluctuating patterns of intra-mesocycle training workloads and concomitant neuromuscular performance responses was noted over time for Acute Training Load (ATL) with PF (r = -0.59; p < 0.05) (Chapter 5). Corresponding analysis of training workloads and conditioning status as influencers of post-match strength resilience and recovery identified potential for aspects of NM performance to be altered by careful manipulation of antecedent training workloads (r = 0.59-0.62; p < 0.05) (Chapter 6). Within routine aspects of the competitive season, greatest deficits in NM performance were observed immediately following match-play (p < 0.05; Cohen’s d: 0.32 [PF] and 0.89 [EMD]). Subsequently, using a potent, controlled exposure to exercise stress, an intermittent isometric fatigue trial (IIFT) was deployed to examine concurrent SM and NM performance responses while exploring alterations in player perceived capabilities. Declines in PF, rate of force development (RFD) and EMD performance following the IIFT reached statistical significance with effect magnitudes larger than observed within the ecologically relevant settings (p < 0.001; Cohen’s d: 0.58 [PF], 0.52 [RFD] and 2.34 [EMD]). Interestingly, SM performance capabilities remained intact following the IIFT (p > 0.05). Additionally, although both CR-10 and PTD ultimately demonstrated efficacy in predicting exercise cessation, a significant interaction effect (p < 0.01) was observed indicating a divergence between candidate explanatory paradigms of self-perception of capabilities for players within the task. This thesis has increased current knowledge and understanding by providing a novel exploratory evaluation of sensorimotor and neuromuscular performance capabilities in early career professional soccer players. The findings presented in this thesis will better inform future studies on conditioning soccer players and allow more targeted prophylactic strategies to be implemented by performance support staff. Key words: Sensorimotor, neuromuscular, soccer