The Effect of Neuromuscular Training on Fatigue Resistance in Female Footballers

ACL injury is predominant in female footballers largely due to a combination of kinetic and neuromuscular risk factors. The majority of ACL injuries in football occur during an unanticipated cutting manoeuvre, and the risk of this injury is heightened during the final 30 minutes of each half of match-play. Due to an increased injury incidence towards the end of match-play, it is possible that fatigue might serve as a risk factor for ACL injury. However, there currently exists limited research examining the effects of fatigue on a variety of kinetic and electromyographic variables in female footballers during an unanticipated cutting manoeuvre. Neuromuscular training programmes have been utilised in injury prevention studies and proven effective in reducing injury incidence by improving certain kinetic and neuromuscular ACL injury risk factors. The overall aim of this thesis is to examine the effectiveness of neuromuscular training on the fatigue resistance of ACL injury risk factors in female footballers. Study one of this thesis examined the reliability of a combination of kinetic and electromyographic measures in female footballers performing an unanticipated cutting manoeuvre. There were no significant differences in mean values and large to nearly perfect correlations (ICC = 0.49 - 0.96) for all kinetic variables. The majority of kinetic variables displayed a CV of less than 10%, with the exception of loading rates and time to peak force (CV% = 17.33 - 24.51). In comparison to previous research, electromyographic variables displayed a greater range of typical error (CV% = 17.6 - 129.2); however, the majority of electromyographic variables displayed a large, very large or nearly perfect correlation (ICC = 0.26 – 0.91) and no significant differences in the mean score. In line with previous research, standards of reliability, and anticipated changes in response to acute fatigue, all kinetic and electromyographic variables were deemed acceptable to use in subsequent studies. Kinetic variables showed better reliability than electromyographic variables, which was to be expected due to electromyographic measures being a physiological measure. Previous research has established that 16 - 18 year old female footballers are at highest risk of ACL injury, and it is most commonly caused during performance of an unanticipated cutting manoeuvre. It has also been established that the majority of injuries in female football are sustained in the last 30 minutes of each half when fatigue is present. Therefore, acute fatigue appears to be an influential risk factor for ACL injury. Study two of this thesis examined the effects of acute fatigue on the electromyographic and kinetic ACL injury risk factors in 16 - 18 year old female footballers, when performing an unanticipated cutting manoeuvre. A modified SAFT90 protocol was used to mimic football match-play. Data showed that during the unanticipated cutting manoeuvre following the SAFT90, participants produced greater GRF (vGRF; possibly, apGRF very likely), lower GCT (very likely), increased background hamstring activation (0 - 30 ms; very likely) and increased short-latency feedback activation of the hamstrings (31 - 60 ms; likely and possibly). Results suggested that following a simulated match-play protocol, female footballers experienced greater force absorption while utilising a safer muscle recruitment strategy. Therefore, injury prevention training should seek to improve a player’s aility to tolerate ground reaction forces when experiencing acute fatigue, with a large emphasis on enhancing neuromuscular control within the hamstrings muscle group

Noncontact injuries in Scottish hockey: A study of epidemiology, current practice and a preventative measure

Introduction: There is limited evidence on noncontact injury epidemiology, current warm-up practice and exercise interventions used to reduce injuries in hockey. Therefore, the aims of this thesis are to investigate (1) noncontact injuries, (2) current warm-up practice and (3) the effects of a novel warm-up on female sub-elite hockey players in Scotland. Methodology: Study 1 was an online injury survey on 317 hockey players focussing on noncontact injuries. Study 2 was an observational study that investigated the current warm-up practices of 17 hockey teams. Study 3 was a controlled study that used 40 female hockey players and explored the effects of an 8-week hockey-specific neuromuscular training programme (NMTP) on electromyography, kinematics and kinetics during a sagittal plane hop, hop and twist and unanticipated sidecut. Results: Study 1 showed that the most common injuries were affecting the knee and hamstrings (0.89 and 0.69/1000 hours respectively) with no timeloss (31.4%) or mild to moderate injuries (30.3%) and usually occurred during sidecutting, sudden acceleration and landing (19.6%, 13.8% and 12.9% respectively). The injuries were more frequently occurring to females than males 4.73 vs 3.47/1000 hours. Study 2 revealed a warm-up time of 20 minutes including pulse raiser, activate and mobilise and potentiate elements. The occurrence of static stretching was greater (41.2%) than neuromuscular training (11.7%). Study 3 showed some significant increases in muscle activation for Gastrocnemius, Quadriceps and Gluteals both pre-and post-landing, with greater increases in the intervention group. There were significant reductions in maximum knee abduction, excursion and the rate of force development following 8-weeks of neuromuscular training. There were no significant differences in performance. Conclusion: Noncontact hockey injury epidemiology requires further research and the current provision of warm-ups should be evidence-based. A novel hockey-specific NMTP can elicit some significant changes in muscle activity, kinematics and kinetics that may reduce the risk of noncontact injuries

Epidemiology of Injury in English Women's Super league Football: A Cohort Study

INTRODUCTION: The epidemiology of injury in male professional football has been well documented (Ekstrand, Hägglund, & Waldén, 2011) and used as a basis to understand injury trends for a number of years. The prevalence and incidence of injuries occurring in womens super league football is unknown. The aim of this study is to estimate the prevalence and incidence of injury in an English Super League Women’s Football squad. METHODS: Following ethical approval from Leeds Beckett University, players (n = 25) signed to a Women’s Super League Football club provided written informed consent to complete a self-administered injury survey. Measures of exposure, injury and performance over a 12-month period was gathered. Participants were classified as injured if they reported a football injury that required medical attention or withdrawal from participation for one day or more. Injuries were categorised as either traumatic or overuse and whether the injury was a new injury and/or re-injury of the same anatomical site RESULTS: 43 injuries, including re-injury were reported by the 25 participants providing a clinical incidence of 1.72 injuries per player. Total incidence of injury was 10.8/1000 h (95% CI: 7.5 to 14.03). Participants were at higher risk of injury during a match compared with training (32.4 (95% CI: 15.6 to 48.4) vs 8.0 (95% CI: 5.0 to 10.85)/1000 hours, p 28 days) of which there were three non-contact anterior cruciate ligament (ACL) injuries. The epidemiological incidence proportion was 0.80 (95% CI: 0.64 to 0.95) and the average probability that any player on this team will sustain at least one injury was 80.0% (95% CI: 64.3% to 95.6%) CONCLUSION: This is the first report capturing exposure and injury incidence by anatomical site from a cohort of English players and is comparable to that found in Europe (6.3/1000 h (95% CI 5.4 to 7.36) Larruskain et al 2017). The number of ACL injuries highlights a potential injury burden for a squad of this size. Multi-site prospective investigations into the incidence and prevalence of injury in women’s football are require

Maximal punching performance in amateur boxing: An examination of biomechanical and physical performance-related characteristics

Punches in boxing are intricate actions requiring the coordinated and synergistic recruitment of leg, trunk and arm musculature. Maximal punches can have a marked impact on the outcomes of boxing contests. Currently, there is an absence of research appraising the biomechanics and physical performance-related qualities associated with boxing punches, and as such, there are no practical guidelines pertaining to resistance training and its impact upon these important characteristics. In this respect, coaches and boxers are reliant consequently upon non-scientific approaches to training and contest preparation. Thus, the purpose of this thesis was to quantify the biomechanics and physical performance-related qualities associated with maximal punching techniques common to amateur boxing, and investigate the extent to which resistance training enhances such features. Study 1 quantified the three-dimensional kinetics and kinematics of maximal punches common to boxing competition to identify the differences between punch types (straights, hooks, and uppercuts), whilst Study 2 investigated the movement variability of these measures across punch types. These studies revealed significant differences for the majority of kinetic and kinematic variables between punch types. High within-subject, between-subject, and biological variability were recorded for the same variables across punch types, independent of the amount of boxing experience. These findings confirm that kinetic and kinematic characteristics vary from punch to punch, with boxers appearing to manipulate kinematic variables in order to achieve a consistent intensity and end-product. Study 3 quantified the relationships between physical performance-related traits and kinetic and kinematic qualities of maximal punches, and revealed moderate-to-large associations with muscular strength and power. From this, Study 4 appraised the extent to which strength and contrast resistance training enhanced maximal punch biomechanics and physical performance-related qualities. The findings highlighted that contrast training was superior among male amateur boxers over a six-week intervention, though strength training alone also brought about improvements. This current research has advanced our understanding of maximal punching and the influence of resistance training on a variety of its determinants. Nonetheless, future research is required to identify if the same findings can be generalised to higher standards of boxing and whether alternative strength and conditioning strategies are equally, or more effective

Social Identity, Mental Toughness, and Behavioural Intentions as Antecedents of Overuse Injury Pain in Physical Activity Contexts

Psychological factors specific to overuse injury pain in physical activity contexts were explored within a social identity theoretical framework. Study 1 involved development of a method for designating overuse injury pain occurrence of hikers (N = 751), along with exploration of relationships between psychological measures, overuse injury pain occurrence, and effort levels. The findings of this cross-sectional, mixed-methods investigation revealed that social identification, social identity content, and mental toughness differentiated hikers who incurred overuse injury pain or selected a higher-effort behaviour from those who did not. From qualitative analysis, several social identity constructs (i.e., group member’s presence, in-group status, social creativity, additional social identity content) emerged as contributors to overuse injury occurrence. The focus of Study 2 was a prospective examination of the aforementioned psychological factors in relation to overuse injury severity of hikers (N = 283). Additionally, the Test of Intentions to Reduce Effort (TIRE) was developed to identify individuals with susceptibility to higher overuse injury severity. Results provided evidence of factorial, construct, and predictive validity of TIRE factor scores. TIRE factors and social identity content significantly predicted higher severity of hikers’ overuse injury pain. Mental toughness scores moderated the relationship between social identification and overuse injury severity. Study 3 consisted of a qualitative examination of social identity mechanisms of overuse injury pain in a physical activity context, CrossFit®, involving the presence of group leaders, and in which group members view each other. Findings revealed mechanisms pertaining to social identity content, in-group status, and social threats. Overall, the findings support a new means for assessing overuse injury occurrence and susceptibility to higher overuse injury severity, whilst demonstrating the potential applicability of social identity theory to the study of overuse injury. Knowledge gained may ultimately aid development of interventions to reduce overuse injury occurrence and severity of physical activity participants

Social Identity, Mental Toughness, and Behavioural Intentions as Antecedents of Overuse Injury Pain in Physical Activity Contexts

Psychological factors specific to overuse injury pain in physical activity contexts were explored within a social identity theoretical framework. Study 1 involved development of a method for designating overuse injury pain occurrence of hikers (N = 751), along with exploration of relationships between psychological measures, overuse injury pain occurrence, and effort levels. The findings of this cross-sectional, mixed-methods investigation revealed that social identification, social identity content, and mental toughness differentiated hikers who incurred overuse injury pain or selected a higher-effort behaviour from those who did not. From qualitative analysis, several social identity constructs (i.e., group member’s presence, in-group status, social creativity, additional social identity content) emerged as contributors to overuse injury occurrence. The focus of Study 2 was a prospective examination of the aforementioned psychological factors in relation to overuse injury severity of hikers (N = 283). Additionally, the Test of Intentions to Reduce Effort (TIRE) was developed to identify individuals with susceptibility to higher overuse injury severity. Results provided evidence of factorial, construct, and predictive validity of TIRE factor scores. TIRE factors and social identity content significantly predicted higher severity of hikers’ overuse injury pain. Mental toughness scores moderated the relationship between social identification and overuse injury severity. Study 3 consisted of a qualitative examination of social identity mechanisms of overuse injury pain in a physical activity context, CrossFit®, involving the presence of group leaders, and in which group members view each other. Findings revealed mechanisms pertaining to social identity content, in-group status, and social threats. Overall, the findings support a new means for assessing overuse injury occurrence and susceptibility to higher overuse injury severity, whilst demonstrating the potential applicability of social identity theory to the study of overuse injury. Knowledge gained may ultimately aid development of interventions to reduce overuse injury occurrence and severity of physical activity participants