Includes abstract. Includes bibliographical references.

Includes abstract. Includes bibliographical references (leaves 69-74).

Includes bibliographical references.

Bibliography: leaves 67-73.

Includes abstract. / Includes bibliographical references. / Distance running has become increasingly popular in recreational runners. The gastrocnemius is the main muscle used for propulsion in running, and may be at risk for injury due to its morphology. In previous studies, changes in the morphology and architecture of the gastrocnemius muscle have been evident following training, but it is unclear whether these changes are related to training or youth. Previous studies of runners have shown a decrease in gastrocnemius and soleus flexibility, as well as changes in the fascicle length and pennation angle. Gastrocnemius volume has not been compared in low physical activity and active participants. Physiological cross sectional area, based on volume and fascicle length measurements may also provide valuable information about the muscle’s ability to produce force. Ultrasound may be a useful tool in assessing potential training adaptations in the morphology and architecture of the gastrocnemius muscle. The aim of this cross-sectional descriptive study was to assess the differences in architecture and function of the gastrocnemius in endurance runners compared to low physical activity participants. (a) To assess differences in calf function and flexibility between endurance runners and low physical activity individuals, and between male and female participants; (b) To determine differences in gastrocnemius muscle architecture and composition between endurance runners versus low physical activity individuals, and between males and females; and (c) To determine whether there are any relationships between training factors and the structure and function of the gastrocnemius muscle. Thirty participants between 20 and 45 years old were recruited for this study and allocated to groups based on their level of physical activity. The low physical activity group (n = 14) were not participating in any regular physical activity, while the endurance running group (n = 16) were running a minimum of 40 km.wk-1, and had participated in at least one full marathon (42.2 km) in the previous six months. All participants completed informed consent, a physical activity and training questionnaire, and a Physical Activity Readiness Questionnaire (PAR-Q) at the first session. The first session also included body composition measurements; ultrasound imaging to measure gastrocnemius length, thickness, fascicle length, pennation angle and volume; and familiarisation with all physical tests. Physical tests were conducted in the second session, including gastrocnemius and soleus flexibility, calf raise endurance and vertical jump height to assess the function of the components of the triceps surae. There were no significant differences between low physical activity and running groups for gastrocnemius thickness, fascicle length, pennation angle and gastrocnemius length. Gastrocnemius volume (p = 0.02) and physiological cross sectional area (p = 0.01) were significantly greater in the running group compared to the low physical activity group. There were no significant differences between low physical activity and running groups in flexibility or vertical jump height, although male participants had significantly decreased gastrocnemius muscle flexibility (p = 0.046) and significantly greater vertical jump heights (p = 0.01) than females. Calf raise endurance was significantly greater in the running group than in the low physical activity group (p = 0.03). Endurance running leads to specific adaptations in participants in both structure and function. While ultrasound appears to be a reliable measure for assessing architectural components of the gastrocnemius muscle in both active and inactive populations, further cadaver studies may provide valuable information on muscle architecture.

Includes bibliographical references (leaves 52-61). / With regards to swimming, cycling and running, several studies have investigated the physiological and genetic contribution of performance in athletes, different training programs and athletes' adaptation to these programs. Other studies have investigated levels of pain and relative perception of effort (RPE) and the athlete's ability to recover after endurance races... The aim of this thesis is to review the literture which discusses the background to the questions outlined above (Chapter 2), followed by a study which attempts to answer these questions (Chapter 3). The aim of the study was to establish whether the training methods in preparation for the Ironman were related to subjective pain and perception of effort during the race, and the recovery time after the race. The study was designed to establish whether there were differences in these variables between triathletes who predicted their finishing time accurately compared to those triathletes wo under-or over-predicted their performance.

Includes bibliographical references (leaves 104-110). / The grace and ease with which a dancer entertains an audience is deceptive with respect to the sweat and tears shed to achieve such elegance of movement. Ballet demands great flexibility and strength. This is showcased as a story told through movement, full of emotion and expressed to music. As a physiotherapist on watches a ballet in absolute awe of the stresses the human body has to endure. What adaptations are necessary within the musculoskeletal system to allow such movement? Do these adaptations lead to injury?

Includes bibliographical references.

The aim of this study was to identify the possible risk factors for the development of lower limb musculoskeletal injuries in novice runners. The specific objectives of this study were: (a) to describe the demographic and training characteristics of novice runners; (b) to establish the incidence of self-reported running-related injuries in novice runners; (c) to determine if specific intrinsic factors, namely age, gender, body mass index, quadriceps angle, foot alignment, hamstring flexibility, balance, muscle power and a history of previous injury were risk factors for lower limb musculoskeletal injuries in novice runners; and (d) to determine if specific extrinsic factors, namely training frequency, session duration, and intensity were risk factors for developing lower limb musculoskeletal injuries in novice runners.

Background: Swimming is a popular competitive and recreational sport performed worldwide by all generations. Although swimming is associated with many positive health benefits, swimmers are at risk of developing musculoskeletal injuries. In particular, competitive swimmers may be at increased risk of injury, due to regular participation in demanding training regimes. Adolescent swimmers may be at increased risk of injury due to physiological and biological vulnerability associated with growth and development. However, there is a lack of evidence regarding the epidemiology of injuries in competitive adolescent swimmers. Aim: The aim of this study was to determine the relationship between injury incidence and potential risk factors in adolescent swimmers over a 24 - week period. Specific Objectives: (a) To describe the demographic and training characteristics of competitive adolescent swimmers; (b) to establish the incidence and nature of self - reported swimming - related injuries in competitive adolescent swimmers; (c) to determine if any specific intrinsic factors and extrinsic factors were associated with increased risk of injury in competitive adolescent swimmers. Methods: Twenty three competitive adolescent swimmers aged 12 to 18 years were recruited for the study. Swimmers attended a study information session and parents/legal guardians were emailed information sheets and informed consent forms. All participants brought signed informed consent forms from parents/legal guardians to the baseline data collection session. At baseline testing participants signed their own informed assent forms and completed the baseline questionnaire, anthropometry measurements, glenohumeral range of movement measurements, the Beighton score and glenohumeral and knee muscle strength measurements. Participants were advised on how to complete the electronic injury report and training questionnaire. A familiarisation trial - run of the survey was completed in the week following baseline testing. Formal data collection commenced two weeks after baseline testing. Participants were required to submit the injury report and training questionnaire on a weekly basis for the 24 - week study period. Results: The mean age for commencement of swimming training in both the injured and uninjured groups was approximately 7.5 years. The injured group had significantly decreased subscapularis muscle strength (p = 0.02) and significantly higher average training session distances (p = 0.04), compared to the uninjured group. Fourteen participants (60%) sustained injuries during the 24 - week study period. The injury rate was 22.4 per 1 000 athletic exposures (AE's). Sixty injuries were sustained in total; 16 were index, and 44 were recurrent injuries. The most common injury location was the knee joint (n = 20). The only factors associated with increased injury risk in this study were previous injury history (OR: 7.50; 95% CIs 1.02 - 55.00) and reduced percentage of time in breaststroke training (OR: 12.83; 95% C I s: 1.69 - 97.19). Few swimming training sessions were modified or changed due to injury, and the majority of injurie s did not receive any treatment. Conclusion The injury incidence of adolescent competitive swimmers attending a Johannesburg - based swim squad is high. In addition, the high number of recurrent injuries, the minimal adaptation of training loads in response to injury, and the low access to appropriate treatment suggest a lack of knowledge or poor practices regarding swimming - related injuries. Pre - season screening, specific to swimming, could assist in identifying weakness and potential risk factors for injury in this vulnerable age - group. Improving health literacy with education in swimmers, coaches and parents could reduce future injury incidence rates. Therefore, further research is needed regarding injury incidence, risk factors and training profiles of this population. Moreover, consensus regarding injury definitions and training loads in adolescent swimmers is needed to standardise reporting and to facilitate further research in this field.