Bibliography: leaves 77-94. / Patellofemoral disorders are amongst the most common clinical conditions encountered in the sporting and general population [8, 33, 68]. Patellofemoral pain (PFP) is usually described as diffuse, peripatellar, anterior knee pain [8, 61].

Includes abstract. Includes bibliographical references.

Includes bibliographical references. / Several studies on European players at the elite or professional level have shown a high risk of injury. However, the studies used different data collection methods, making it difficult to compare results. This suggested a need to standardise the definition of an injury and method of data collection. There are no data on injuries associated with football in South Africa, which makes it difficult to develop an evidence-based strategy to manage injuries associated with football. Therefore, in an attempt to address the deficiency on soccer related injuries in South Africa, a Professional Soccer League (PSL) team (AJAX CT) was monitored throughout the season by the medical support staff of the team using the F-MARC data collection system devised by FIFA. The main objective of this study was to undertake a retrospective epidemiological study documenting the incidence of injury in this team and the exposure time (practice and match) of the players over a full season.

Includes abstract. / Includes bibliographical references. / Mature adults are at risk of an accelerated age-related reduction in physical function. Declines in aerobic power, functional strength, motor abilities, flexibility and health-related quality of life are thought to be primarily due to reduced physical activity levels with increasing age. Leisure time physical activity (LTPA) has been extensively investigated and is widely advocated for the preservation of function with ageing. However there is a lack of evidence regarding the relationship between LTPA and the individual components of health-related fitness, particularly motor abilities. It is therefore unclear what types of LTPA (endurance, neuromuscular LTPA or games) should be prescribed by health professionals for the development of health-related fitness parameters. Aim: To examine the relationship between LTPA and components of health-related fitness in healthy mature adults. Specific Objectives: (a) To describe the preferred mode(s) and weekly duration of recent LTPA in currently active male and female participants. (b) To describe the preferred mode(s) and years of participation in long term LTPA, in currently active and inactive male and female participants. (c) To determine if there were significant differences in anthropometry and selected health-related fitness components, in currently active and inactive male and female participants. (d) To determine the relationships between recent participation in different types of LTPA (endurance, neuromuscular or games) and total weekly duration of LTPA; and anthropometry and selected components of health related fitness in currently active male and female participants. (e) To determine the relationships between former participation in different types of LTPA (endurance, neuromuscular or games) and years of LTPA participation; and anthropometry and selected components of health-related fitness in currently active and inactive male and female participants. Methods: This study had a descriptive, correlational design. Healthy adults aged between 40 and 60 who either participated in regular LTPA or no LTPA, were recruited for the study. Participants were excluded if they had any acute or chronic injuries; or used any medication that altered heart rate or physical function. Fifty six healthy mature adults between the ages of 40 and 58 years participated in this study. Twenty nine had participated in at least 30 minutes of LTPA, three times per week in the last three months (active group); and twenty seven had not participated in LTPA in the last three months (inactive group). Data were collected in two sessions. In session one, participants gave written informed consent; completed a physical activity readiness questionnaire (PAR-Q) to screen for safe exercise participation; and completed health-related quality of life and LTPA questionnaires. Body composition measurements were also performed. In session two, participants completed a battery of physical tests conducted by a blinded assessor, including: cardiorespiratory fitness (2 km walk test); static and dynamic balance (standing on one leg, tandem walking backwards); agility (Illinois agility test); co-ordination (timed bouncing of a ball along a wall from a fixed distance); upper limb function (modified push-up test); lower limb function (vertical jump test); back muscle endurance (static back extension test); and flexibility (sit-and-reach test).Results: Recently active participants had significantly reduced body mass index (BMI) (p = 0.04), body fat percentage (p = 0.003) and sum of seven skinfold (p = 0.004) measurements, compared to inactive participants. In addition, active participants scored significantly better in the tests for cardiorespiratory fitness (p = 0.0004) and upper limb function (p = 0.01) than inactive participants. Active females had significantly improved cardiorespiratory fitness (p = 0.0002) and agility (p = 0.0004) compared to inactive females. Of the health-related fitness components, only cardiorespiratory fitness and back muscle endurance were related to recent LTPA participation. Motor abilities such as agility and dynamic balance, upper- and lower limb function were associated with long term rather than recent LTPA, particularly with long term endurance, games and years of long term LTPA participation. Discussion and conclusion: Active participants had significantly improved body composition, cardiorespiratory fitness and upper limb function compared to inactive participants in this study. These results support previous research suggesting that regular participation in LTPA may help to slow the age-associated decline in physical function. However no significant differences were found in motor abilities between recently active and inactive participants, and no significant relationships were found between recent LTPA participation and motor abilities. Based on the findings in this study, long term LTPA and participation in games are advised for the development of motor abilities and functional strength, in healthy mature adults. As this study sample reported mainly endurance LTPA recently and on the long term, future research should aim to explore the independent contributions of different types of LTPA (endurance, neuromuscular or games) on aspects of health related fitness. Such information may be very useful clinically to improve the accuracy of exercise prescription. There is also a need to further evaluate the relationship between long-term LTPA and health-related fitness in a larger sample of mature adults.

Includes abstract. / Includes bibliographical references (leaves 98-105). / Aim: To determine the relationship between the paddle grip: handgrip size ratio and associated factors contributing to the development of lateral elbow tendinosis and DeQuervains tenosynovitis in K1 marathon paddlers.

It is known that light muscular activity performed during the immediate post-exercise recovery period, increases the rate at which lactate and protons are removed from the circulation. This study examined the effect which this light activity had on muscle glycogen and lactate levels, as well as the restoration of blood fuel and hormonal homeostasis. A further dimension of the study was to monitor the metabolic adaptations which took place in the inactive leg during light one-legged post-exercise activity. Eight subjects participated in this study. The testing procedure involved three phases: the assessment of each subject's maximal exercise capacity on the cycle ergometer; the imposition of an intense intermittent exercise protocol which was followed by a passive recovery of 90 minutes; and lastly, the repetition of the exhaustive intermittent protocol followed by a partially-active recovery phase during which the subject cycled with one leg at approximately 30 percent of two-legged VO2. max. for the first 45 minutes of the 90-minute recovery period. During the latter two phases, blood samples and muscle biopsies were taken at rest and during the post-exercise recovery. The light one-legged activity expedited the return of blood lactate and pH levels to basal values (p < 0,01), during the initial 30 minutes of recovery but slowed down the removal of lactate and protons during the latter 15 minutes of the active recovery. There were no significant differences in the blood glucose, pyruvate, alanine, and insulin levels during the different recovery protocols, but plasma glucagon levels were significantly lower <p<0,01) during the active recovery. The major finding was that glycogen resynthesis was not significantly <p>0,05) delayed as a result of activity during the immediate post-exercise period, but that muscle lactate levels were significantly lower in the passive leg than in the active leg after the first 45 minutes of the recovery period. As resynthesis of glycogen took place during the active recovery, this study appeared to indicate (i) that lactate oxidation was an important source of substrate during the initial 30 minutes of the active recovery (ii) that oxidation was possibly the primary fate of lactate during the active post-exercise recovery period and (iii) that intramuscular glyconeogenesis in the fast-twitch muscle fibres of the previously active legs was a distinct possibility. Apparent suprabasal production of lactate in the active fibres of the active leg during the latter stages of the active recovery, however, appeared to indicate partial reliance on exogenous glucose as substrate in these fibres during this stage of the recovery.

The aim of this study was to determine the prevalence of lower back pain (LBP) in the running population and any initiating or aggravating factors. The aetiology of low back pain in runners was also investigated. A random sample population of 225 roadrunners were interviewed following the completion of six local road races. A further subgroup (n = 52) (LBP group as well as control group) of these runners was evaluated to determine if there were any biomechanical; muscle strength, flexibility and stability measures; as well as any training protocols which were more commonly associated in those runners who complained of LBP. Questionnaires were completed by 225 runners and a detailed clinical evaluation was performed to identify the incidence and aetiology of running-related lower back pain. Attention was focussed on the lumbar-pelvic muscles in terms of their flexibility, strength and coordinating ability as well as static biomechanical measures of the lower limb. LBP in runners was found to be common with an injury risk of 1.42 injuries per 1000 running hours. This running-related LBP seldom forced the athlete to stop running yet did affect running performance. It was associated with any increase in the running load. Hip flexor inflexibility on the left (p = 0.07); short hip adductor muscle length (p = 0.055), hamstring inflexibility (p = 0.09) and iliotibial band inflexibility (p = 0.036) on the right were found to be more common in the LBP group. The abdominal muscles were weaker in the LBP group when assessed in the trunk curl-up test (p = 0.0085) and the stabilising ability (p = 0.032) for this group was judged to be poor. Biomechanically, only a marginal difference was found between those with and without LBP (p = 0.077) with regard to the hindfoot and forefoot postures which were valgus and varus respectively for the lower back pain group. Lumbar intervertebral joints were mostly hypomobile (p = 0.004) in the LBP group. Adherence to a poor training regime (excessive running distances and frequencies) was associated with the LBP group. Attention to correct training patterns and adequate muscle control (strength, coordination and flexibility) is suggested to protect from this running-related LBP. Further research into a comparison of rehabilitation protocols is required to validate these findings.

Bibliography: leaves 86-99.

The effect of the long acting dihydropyridine calcium channel antagonist, amlodipine, on the exercise performance of hypertensive patients is not known. The aim of this study was to determine the effects of amlodipine on maximal (MAX), prolonged submaximal (PSX) and on skeletal muscle function (SMF) in patients with mild hypertension. In a double-blind randomised crossover trial, ten physically active hypertensive patients performed i) graded exercise to exhaustion for determination of maximal oxygen consumption (VO₂ₘₐₓ), peak heart rate (HR) and systolic blood pressure (SBP); ii) PSX at 75% VO₂ₘₐₓ to determine, cardiorespiratory responses, cardiac output (Q), blood lactate [La], free fatty acid [FFA], glucose [G] concentrations and ratings of perceived exertion (RPE), and iii) tests of isometric SMF including maximal voluntary contraction (MVC) and time to fatigue (TTF) during repetitve isometric MVC's. Tests were performed following two week ingestion of amlodipine (5 mg daily) or placebo seperated by a two week washout period. Resting SBP was decreased following ingestion of amlodipine (142 ± 13 vs l33 ± 12 mmHg; vs placebo: [mean± SD]; P<0.05). However, VO₂ₘₐₓ ( 31 ± 5 vs 33 ± 5 mlO₂.kg.min⁻¹ ; amlodipine vs placebo), peak heart rate ( 167 ± 12 vs 165 ± l6b.min⁻¹;amlodipine vs placebo)and peak SBP(l8l ±21 vs 170± 16mmHg; amlodipine vs placebo) were not reduced following ingestion of amlodipine. Submaximal cycling time. VO₂, Q, BP, HR, ventilation, RPE, [FFA], [La] and [G] during PSX were unaltered following ingestion of amlodipine. Similarly ingestion of amlodipine did not alter tests of isometric SMF. These data suggest that: i) ingestion of amlodipine lowers resting SBP but does not alter the normal haemodynamic response during exercise; ii) MAX, PSX exercise performance and SMF are unaltered following ingestion of amlodipine in athletic hypertensive patients. These findings suggest that the regulatory mechanisms which maintain haemodynamic homeostasis during maximal and submaximal exercise are not influenced by ingestion of amlodipine in athletic hypertensive patients.

Background: Involvement in sports has numerous well-documented physiological and psychological benefits but also carries a risk of injury. Due to the contact nature of Rugby, involvement in the game carries a greater risk of injury compared to other sports. The tackle phase of the game has resulted in the most number of injuries in all levels of the game. Coaches are key elements in developing players and implementing injury prevention programmes. Certain coach behaviours may influence a player’s attitude, in turn the player’s behaviours, when implementing tackle techniques during training sessions and matches. Player behaviour has previously been identified as a risk factor for sustaining, or causing, an injury during a tackle. Objective: To examine the relationship between reported coaching behaviours and learning resources on players’ attitudes and behaviours towards injury prevention and performance in the rugby tackle. Methods: This cross-sectional survey used a questionnaire comprising a 5-point Likert scale to assess junior rugby players’ (n=164) attitudes (importance) and behaviours (frequency and quantity). The main outcome measurements were the relationships between reported tackle coaching methods and the players' tackle training attitudes and behaviours using the χ² test and Cramer's V. Results: Player-rated importance of injury prevention was positively correlated with verbal instruction from the coach to the individual player (29% somewhat important - very important, χ² (16)=30.41, p<0.05, Cramer's V=0.22, moderate) and to the entire team (34% somewhat important-very important, χ² (16)=34.05, p<0.01, Cramer's V=0.23, moderate). The more time spent by the coaches on teaching proper techniques to prevent injuries, the higher players rated the importance of injury prevention (28% somewhat important-very important, χ² (16)=29.13, p<0.05, Cramer's V=0.21, moderate). Training books as a learning resource was positively associated with how important players rated tackle injury prevention (27% somewhat important-very important/much-very much, χ² (16)=28.67, p<0.05, Cramer’s V=0.21, moderate) and performance (32% somewhat important-very important/much-very much, χ² (16)=27.22, p<0.05, Cramer’s V=0.21, moderate). Training videos, as a learning resource, was also positively associated with the importance of tackle performance (32% somewhat important-very important/much-very much, χ² (16)=27.22, p<0.05, Cramer’s V=0.21, moderate) but not injury prevention (39% somewhat important-very important/much-very much, χ² (16)=21.50, p<0.05, Cramer’s V=0.18, weak) Conclusions: This research reports on the association between reported coaching behaviours and learning resources on players’ attitudes and behaviours towards injury prevention and performance in the tackle in rugby. Reported coaching behaviours, which incorporated individual and team verbal instructions when teaching tackle techniques to prevent injuries, resulted in more risk adverse player attitudes towards injury prevention when performing the tackle skill in training and matches. When the goal was to improve tackle performance, more importance is given to training proper technique in the tackle when compared to the goal of preventing injury. Players identified training videos and training books as the most preferential learning resources for improving tackle performance. Training books were also identified as an important learning resource with regards to tackle-related injury prevention attitudes and should be explored further.