Effect of repeated eccentric demands placed on the lower limb musculature during simulated Rugby Union play
- Authors: Brown, Lisa Gill
- Date: 2010
- Subjects: Sports injuries , Muscles -- Wounds and injuries , Tendons -- Wounds and injuries , Muscles -- Examination , Rugby football injuries , Rugby Union football players
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5114 , http://hdl.handle.net/10962/d1005192 , Sports injuries , Muscles -- Wounds and injuries , Tendons -- Wounds and injuries , Muscles -- Examination , Rugby football injuries , Rugby Union football players
- Description: Epidemiological studies consistently report that muscular strains are a primary injury type in rugby union with the majority of the strains occurring to the quadricep and hamstring musculature. Recently it has been suggested that poor eccentric muscular strength is a precursor to hamstring and quadriceps strains during intermittent sports that require rapid acceleration and deceleration. Despite the high incidence of these muscle injuries in Rugby Union there has been little research into the possible mechanisms involved. Thus, the purpose of this study was to measure the physiological and perceptual responses during a simulated Rugby Union laboratory protocol and further, to identify changes in muscle recruitment patterns and muscle strength over time by comparing this protocol to a continuous, constant load protocol covering the same distance. The experimental condition (EXP) required university level players to perform 80 minutes of simulated rugby union play in a laboratory setting (on a walkway of 22m) which was compared to that of a control condition (CON) which involved subjects covering the same distance, at a constant speed of 4.2km.h-1 on a treadmill. Physiological, biophysical and perceptual responses were measured pre-, at half-time and post-protocol. Heart rate was significantly (p<0.01) greater as a result of EXP in comparison to the CON. Electromyography (EMG) of the vastus medialis was significantly (p<0.01) greater during the CON protocol. The EXP condition elicited higher iEMG activity in the hamstring musculature at all time intervals. In addition the iEMG of the semitendinosus decreased significantly (p<0.01) as a result of the EXP protocol. Peak eccentric knee extensors (EXT) (-13.19%) and flexors (FLEX) (-12.81%) torque decreased significantly during the experimental protocol. After passive half-time (236.67 + 56.27Nm (EXT) and 173.89 + 33.3NM (FLEX)) and at the end of the protocol (220.39 + 55.16Nm and 162.89 + 30.66Nm) reduced relative to pre protocol (253.89 + 54.54Nm and 186.83 + 33.3Nm). Peak eccentric knee extensors did not change during the control protocol. „Central‟ and ‟Local” Rating of Perceived Exertion values were significantly (P<0.01) greater during the EXP protocol with an increased incidence of hamstring discomfort and perceived pain (5 out of 10). The EXP protocol resulted in significantly (p<0.01) increased incidence of delayed onset muscle soreness (DOMS). In conclusion, a stop-start laboratory protocol elicited increased heart rate, negatively impacted on muscle activity of the hamstrings, decreased eccentric strength in the lower limb musculature, resulted in increased ratings of „Central‟ and „Local‟ exertion and increased pain perception and increased incidence of DOMS. Thus, a stop-start rugby specific laboratory protocol has a negative impact on performance. Due to the specificity of the protocol being designed to match the demands of competitive match play it is expected that these changes in heart rate, muscle activity and strength, particularly eccentric strength, will impact negativity on performance during rugby match play and increase the likelihood of injury
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- Date Issued: 2010
A case study investigation of the neuropsychological profile of a rugby player with a history of multiple concussions
- Authors: Case, Stephanie
- Date: 2006
- Subjects: Rugby football injuries , Brain -- Concussion -- Complications , Neuropsychological tests , Head -- Wounds and injuries -- Complications , Sports injuries -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3165 , http://hdl.handle.net/10962/d1007727 , Rugby football injuries , Brain -- Concussion -- Complications , Neuropsychological tests , Head -- Wounds and injuries -- Complications , Sports injuries -- Psychological aspects
- Description: sustained multiple concussions may be at risk of cumulative impairment. The role of neuropsychological testing in the management of sports-related concussion is a contentious and challenging issue which has gained credibility given the lack of clear and well-established guidelines pertaining to the diagnosis, assessment and return-to-play decisions following concussion. Despite various traditional paper and pencil tests being shown to be effective indicators of postconcussive neuropsychological dysfunction, testing has not been widely implemented, due to time- and labour-demands. ImPACT, a computer-based neuropsychological assessment instrument, has been recognised as a valid and reliable tool in the monitoring of athletes' symptoms and neurocognitive functioning preseason and postconcussion. As a part of larger-scale concussion research conducted on top-team university rugby players, this is an in-depth case study conducted on a 20-year old participant with a history of multiple concussions, who was referred following a concussion sustained during the season. The objectives of the study were: (i) to determine the sensitivity of ImPACT versus WAIS-III Digit Span and Trail Making Test during the acute postconcussive phase; and (ii) to examine the sensitivity of ImPACT versus a comprehensive battery of neuropsychological tests to possible residual deficits as a result of the multiple concussions. ImPACT was determined to be more sensitive to acute postconcussive impairment following concussion than Digit Span and Trail Making Test. Furthermore, the ImPACT preseason baseline scores appear to be sensitive to neurocognitive dysfunction, possibly due to cumulative concussive injuries.
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- Date Issued: 2006
"Feeling foggy?": an investigation into the self-reported post-concussive symptoms in rugby union players at university level
- Authors: Boulind, Melissa
- Date: 2005
- Subjects: Brain damage , Brain -- Wounds and injuries -- Complications , Brain -- Wounds and injuries -- Psychology , Sports injuries -- Psychological aspects , Rugby football injuries , Rugby Union football players
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2938 , http://hdl.handle.net/10962/d1002447 , Brain damage , Brain -- Wounds and injuries -- Complications , Brain -- Wounds and injuries -- Psychology , Sports injuries -- Psychological aspects , Rugby football injuries , Rugby Union football players
- Description: A study was conducted on the self-reported symptoms of Mild Traumatic Brain Injury sustained in Rugby Union at the pre- and post-season stages. A full sample of 30 rugby players at Rhodes University was compared to 27 non-contact sport controls. A reduced sample of 20 rugby players and 9 control participants provided improved control for education and IQ and was compared. Measures included the WAIS-III Vocabulary and Picture Completion Sub-tests to estimate IQ level, the symptom checklist on a widely used computer-based program (ImPACT), and a paper and pencil self-report 31-Item Post-Concussion Symptom Questionnaire. Independent and Dependent T-Test comparisons were conducted on the full and reduced samples. The symptoms reported by the rugby group appeared to be more pronounced on both the ImPACT Symptom Scale and the 31-Item Post-Concussion Symptom Questionnaire when compared to the control group at both the pre-and post-season stages. It was concluded that the rugby players demonstrated evidence to support the hypothesis of having sustained more previous concussions and reporting more symptoms at the pre-season stage when compared to comtrol participants. No prevalent changes for either the rugby or control groups were seen in dependent comparisons from pre-to post-season.
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- Date Issued: 2005
Cumulative mild head injury in rugby: a comparison of cognitive deficit and postconcussive symptomatology between schoolboy rugby players and non-contact sport controls
- Authors: Beilinsohn, Taryn
- Date: 2001
- Subjects: Rugby football injuries , Head -- Wounds and injuries -- Psychology , Head -- Wounds and injuries -- Complications , Brain damage
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2931 , http://hdl.handle.net/10962/d1002440 , Rugby football injuries , Head -- Wounds and injuries -- Psychology , Head -- Wounds and injuries -- Complications , Brain damage
- Description: This study investigates the cumulative effects of concussive and subconcussive mild head injury on the cognitive functioning of schoolboy rugby players. A comprehensive battery of neuropsychological tests and a self-report postconcussive questionnaire were administered to top level schoolboy rugby players (n=47), and a non-contact sport control group of top level schoolboy hockey players (n=34). Group comparisons of the percentage of individuals with cognitive deficit were carried out between i) the schoolboy rugby and the schoolboy hockey players, ii) the rugby forward and the rugby backline players; iii) the rugby forward and the schoolboy hockey players and, iv) the rugby backline and the schoolboy hockey players. Results on the neuropsychological test battery did not provide any substantial evidence of a higher level of neuropsychological impairment in the rugby players relative to the control group, or in the rugby forward players relative to the rugby backline players. Results obtained on the postconcussive symptom questionnaire provided tentative indications that the rugby players do report a greater frequency of postconcussive symptomatology. The symptoms most frequently reported were being easily angered, memory problems, clumsy speech and sleep difficulties. It was hypothesized that the absence of cognitive impairment in the schoolboy rugby players compared with that noted for professional players was due to their younger age, relatively high IQ and education level and a less intensive level of physical participation in the sport, and hence less accumulated exposure to the game, thereby decreasing their exposure to mild head injuries. From a theoretical perspective, these pre-existing conditions were considered to act as protective factors against reductions in brain reserve capacity and concomitant susceptibility to the onset of neuropsychological dysfunction.
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- Date Issued: 2001
Heads and tales: the effect of mild head injuries of rugby players: cognitive deficit and postconcussive symptoms
- Authors: Border, Michael Anthony
- Date: 2001
- Subjects: Rugby football injuries , Head -- Wounds and injuries -- Psychology , Head -- Wounds and injuries -- Complications , Brain damage
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:2937 , http://hdl.handle.net/10962/d1002446 , Rugby football injuries , Head -- Wounds and injuries -- Psychology , Head -- Wounds and injuries -- Complications , Brain damage
- Description: This study investigated the cumulative effect of mild head injuries on rugby players. A comprehensive battery of neuropsychological tests was administered and subjects completed a self-report postconcussive symptom questionnaire. Data were collected for the two rugby groups, Springbok rugby players (n = 26) and Under 21 rugby players (n = 19), and for the control group, national hockey players (n = 21). Group comparisons of the percentage of individuals with deficit or self-reported symptomatology were made between: (i) the contact sport groups and the control group; (ii) the forwards and the backs within each rugby group and the rugby forwards and the control group; and (iii) the Springbok and Under 21 rugby players. Broadly speaking, comparative results on the neuropsychological tests and the self-reported postconcussive symptoms clearly distinguished between contact sport players and non-contact sport players and indicated the presence of diffuse brain damage in the contact sport players. There was also clear evidence of positional variation within the rugby groups, with the forwards (more full contact positions) most susceptible to impairment. Neuropsychological test results revealed deficit in information processing speed, attention and concentration, mental flexibility, visual memory and verbal new learning. The most significant neuropsychiatric complaints were reported in the areas of memory, social contact, sensitivity to noise, lowered frustration tolerance, anxiety and worry, and depression. The most sensitive neuropsychological test used in the present study was the Digit Symbol Substitution test. This test clearly distinguished contact sport players from non-contact sport players, and forwards from backs.
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- Date Issued: 2001
Minor "dings" - major effects? a study into the cognitive effects of mild head injuries in high school rugby
- Authors: Ackermann, Tessa Ruth
- Date: 2000
- Subjects: Rugby football injuries , Head -- Wounds and injuries -- Psychology , Head -- Wounds and injuries -- Complications , Head -- Wounds and injuries -- Patients -- Rehabilitation
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:2920 , http://hdl.handle.net/10962/d1002429 , Rugby football injuries , Head -- Wounds and injuries -- Psychology , Head -- Wounds and injuries -- Complications , Head -- Wounds and injuries -- Patients -- Rehabilitation
- Description: The present study is part of a larger and ongoing research initiative investigating the cumulative cognitive effects of mild head injury in rugby union and focused specifically on high school rugby players. A comprehensive battery of neuropsychological tests was administered to top team high school rugby players (n = 47), and a non-contact sport control group of top team high school hockey players (n = 34). Direct comparisons of group mean scores and standard deviations across each neuropsychological test were carried out for the Total Rugby group versus the Total Hockey group as well as for the subgroups Rugby Forwards versus Rugby Backs. A correlational analysis was conducted to ascertain whether a relationship exists between the number of mild head injuries reported by the players and their cognitive test performance. Results of the group comparisons of means and variability on WMS Paired Associate Learning Hard Pairs - Delayed Recall provides tentative indications of the initial stages of diffuse damage associated with mild head injury in the rugby group and provides some evidence for impairment of verbal learning and memory in the Rugby Forwards group. The correlational analysis revealed no significant relationship between number of reported mild head injuries and cognitive performance. The findings and possible latent effects of the multiple mild head injuries reported by the rugby players are discussed in terms of brain reserve capacity theory and suggestions for future research are provided.
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- Date Issued: 2000
The scrum-down on brain damage effects of cumulative mild head injury in rugby: a comparison of group mean scores between national rugby players and non-contact sport controls
- Authors: Finkelstein, Melissa
- Date: 2000
- Subjects: Sports injuries , Head -- Wounds and injuries , Sports injuries -- Psychological aspects , Neuropsychological tests , Rugby football injuries
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:2976 , http://hdl.handle.net/10962/d1002485 , Sports injuries , Head -- Wounds and injuries , Sports injuries -- Psychological aspects , Neuropsychological tests , Rugby football injuries
- Description: The present study comprises the second phase of a larger and ongoing research study investigating the brain damage effects of cumulative mild head injury in rugby. The purpose of this study was to determine whether cumulative mild head injury sustained in the game of rugby would cause brain injury as evidenced by impaired performance on sensitive neuropsychological tests. Participants were Springbok professional rugby players (n = 26), Under 21 rugby players (n = 19), and a non-contact sport control of national hockey players (n = 21). Comparisons of performance were carried out across a spectrum of neuropsychological tests for the three rugby groups (Total Rugby, Springbok Rugby, and Under 21 Rugby) versus the performance of the non-contact sport control group (Hockey Control), as well as comparisons of performance f9r the subgroups of Rugby Forwards versus Rugby Backs. Comparisons revealed a consistent pattern of poorer performance across all rugby groups relative to the performance of the controls on tests highly sensitive to the effects of diffuse brain damage. Within rugby group comparisons (Forwards versus Backs) showed significantly poorer performance for Total Rugby Forwards and Springbok Rugby Forwards relative to the performance of the respective Total Rugby Backs and Springbok Rugby Backs on sensitive, as well as on somewhat less sensitive, neuropsychological tests. The performance of Under 21 Rugby Forwards relative to Under 21 Rugby Backs demonstrated similar trends. Brain reserve capacity theory was used as a conceptual basis for discussing the implications of these findings.
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- Date Issued: 2000
Cumulative mild head injury in rugby: cognitive test profiles of professional rugby and cricket players
- Authors: Ancer, Ruth Lauren
- Date: 1999
- Subjects: Head -- Wounds and injuries , Rugby football injuries , Cricket injuries , Cognitive therapy , Neuropsychological tests
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2925 , http://hdl.handle.net/10962/d1002434 , Head -- Wounds and injuries , Rugby football injuries , Cricket injuries , Cognitive therapy , Neuropsychological tests
- Description: This study investigates the effects of cumulative concussive and subconcussive mild head injury on the cognitive functioning of professional rugby players. A comprehensive battery of neuropsychological tests was administered to 26 professional rugby players and a noncontact sport control group of 21 professional cricket players. The test performances of the rugby players were compared to those of the cricket players. Within the rugby group, forward and backline players were compared. An analysis of mean score differences between the rugby and cricket group failed to support the presence of brain damage effects in the rugby group. However, there was significantly increased variability of scores for the rugby players compared with the cricket players on tests particularly sensitive to cognitive deficit associated with mild head injury. This invalidates the null indications of average effects, indicating that a notable proportion of rugby players’ performances were falling off relative to the rest of the rugby players on tests vulnerable to the cognitive effects of diffuse brain damage. Mean score comparisons within the rugby group indicated that it was the subgroup of forward players, in particular, whose test performances revealed deficits suggestive of cerebral damage. Specifically, deficits were found in working memory, visuoperceptual tracking, verbal memory and visual memory, a pattern of deficits commensurate with cumulative mild head injury. The theoretical perspectives of Satz’s (1997) Brain Reserve Capacity Theory and Jordan’s (1997) ‘Shuttle’ model of variability are drawn upon in order to elucidate research findings and suggestions for future research are provided.
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- Date Issued: 1999
Tackling mild head injury in rugby: a comparison of the cognitive profiles of professional rugby and cricket players
- Authors: Reid, Iain Robert
- Date: 1999
- Subjects: Head -- Wounds and injuries -- Complications , Rugby football injuries , Neuropsychological tests , Cricket -- Accidents
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3043 , http://hdl.handle.net/10962/d1002552 , Head -- Wounds and injuries -- Complications , Rugby football injuries , Neuropsychological tests , Cricket -- Accidents
- Description: The aim of this study was to investigate the effect of cumulative mild head injury on the cognitive functioning of professional rugby players. A comprehensive battery of neuropsychological tests was administered to 26 professional rugby players and to a comparison group of 21 professional cricket players. The group test results of the rugby, cricket, rugby forwards and rugby backline players were each compared with established normative data. Generally, the comparison of the rugby and cricket mean scores relative to the normative data did not reveal significant differences on tests known to be sensitive to the effects of mild head injury. However, the comparison of variability for each of the rugby and cricket playing groups relative to variability for the normative data, revealed a pattern of increased variability among the rugby players. This implies a bimodal distribution in which a significant number of rugby players were performing poorly across these tests whereas a significant proportion were not. This variability effect was accounted for by further mean score comparisons which revealed that, as a group, it was the forward players whose performances were disproportionately poor on tests sensitive to the effects of mild head injury. The implications of these results are developed theoretically within the context of brain reserve capacity theory and suggestions for future research are provided.
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- Date Issued: 1999