Title: Evaluation and training of speed in strength and conditioning preparation of youth basketball players Aims: The aim of this thesis was to validate effectivity of the training program which goal was to improve speed abilities of youth basketball players under 14 year old category during their competitive period. In the same time, I tried to evaluate how changes in selected anthropometric characteristics, practice attendance, game involvement and a length of participation in organized sport and basketball preparation influenced selected speed and agility manifestation. Methods: This thesis uses experiment as its research method. Research sample including youth basketball players (n = 9; mean age 13.39 ± 0.22 years) completed six months long training intervention with elements for speed and general strength development. Players were tested before intervention, three months and six months after beginning of the intervention. Three performance tests were used: 20 m sprint, 15 m flying with 10 m run up and lane agility drill. Video recordings of 20 m sprint and 15 m flying tests were made to evaluate changes in technique of running. Changes and interrelationships of all measured parameters were evaluated in the six months period. Results of the research sample after the first three months of...

Title: Influence of small side games and runs on sprint performance and agility in football players. Purpose: The aim of the thesis is to find out the influence of selected movement interventions (small side games versus runs) on sprint performance and agility in elite football players in U14 category during the preseason period. Methods: The 30-meter Sprint was used to rate speed-strength performance. Players have executed 2 sprints at 30m. Sprint time was measured at 5, 10 and 30m. Agility tests included: test 505 and three-step test. Players also have executed 2 tries (one of each leg). A set of photocells (Alge Timing GmbH, Lustenau, Austria) was used to measure the time of all tests. Results: Both groups significantly improved in the three-step test (p <0.05; r> 0.5). The SSG group, after a two-month intervention, significantly deteriorated in the sprint to 5, 10 and 30m (r = 0.38 - 0.69). The race group did not significantly improve in sprints at 5, 10 and 30m. In the agility test, we saw a significant improvement only in the Run groups and only on the left leg (r = 0.42). Based on the findings, we believe that the training units of the linear speed and speed with the change of direction maintain the level of player's speed during the season. Therefore, I recommend that they should appear in...

Research studies indicate that, by determining the physiological load placed on athletes during competitions, it can aid in the development of strength and conditioning programmes, according to the specific demands placed on athletes (Deutch et al., 1998; Kay&Gill, 2004). Physiological data, specifically on rugby union players, are furthermore limited and more information is needed (Banfi et al., 2006; Deutch et al., 2007). The aim of the study was to investigate the physiological demands of South African male U/21 club rugby players and to establish the correlation between physiological demands experienced during rugby games and practice sessions. Scientific methods to describe physiological demands in sport that are used are heart-rates and blood-lactate measurements (Eniseler, 2005). A group of U/21 rugby players (n=15) of the University of Pretoria (Tuks) rugby club participated in this study. Components that were tested included blood-lactate concentrations and heart-rates during rugby match and practice sessions. The data of the Tuks U/21 team was statistically analysed with descriptive statistics (means and standard deviations). Significant differences between match and practice sessions, at a p-value of P < 0.05, were determined by a dependent t-test. An independent t-test was used to determine significant differences between the forward and backs group (Thomas&Nelson, 2005). The results showed that statistically significant differences (p<0.05) were found between mean heart-rate in the rugby match (154.40 ±13.53) and practice sessions (138.33±4.81). No significant differences were found between peak lactate measurements in the match (5.39 ±2.44) and practice sessions (4.93±1.83). Between the forward and backs group no statistical significance could be found for average heart-rate and blood-lactate levels in practice sessions and the match. The findings of the present study indicate that rugby union matches for club level U/21 players are an intermittent type of activity, with both the use of aerobic and anaerobic energy systems. Additional research on more amateur rugby clubs is needed to extend the knowledge of club level coaches. / Dissertation (MA)--University of Pretoria, 2012. / Biokinetics, Sport and Leisure Sciences / unrestricted

BACKGROUND and OBJECTIVES: Low-back overexertion injuries represent a large proportion of fireground “strains, sprains and muscular pains” and are a leading cause of disability and early retirement in firefighters. Given the inherently hazardous and unpredictable nature of many fireground activities, it is often infeasible to implement “task-focused” ergonomic controls and there are limited options to accommodate injured firefighters. Accordingly, effective and practical “worker-focused” injury prevention approaches are needed. Toward this end, four studies were conducted to address the following global thesis objectives: 1) Examine the possible role that firefighters’ personal movement strategies could have on their occupational low-back loading demands and injury potential; and 2) Compare the effects of two different exercise approaches on firefighters’ occupational low-back loading demands and injury potential. STUDY 1: Low-Back Loading Demands during Simulated Firefighting Tasks – Inter-Subject Variation and the Impact of Fatigue and Gender. Background: Non-modifiable fireground duties are considered hazardous for low-back health, but personal movement strategies could modulate low-back loading demands and injury potential. Study objectives were to quantify low-back loading demands during simulated firefighting tasks and to examine the impact of fatigue and gender on the peak loading response. Methods: Ten men and 10 women performed a battery of laboratory-simulated firefighting tasks before and following repeated bouts of a fatiguing stair-climbing protocol. An EMG-assisted three-dimensional dynamic biomechanical model was used to compute peak L4/L5 joint forces during task performance. Results: Peak low-back loading demands varied considerably between subjects and tasks, but 70% of all loading variables examined were of greater magnitudes in male subjects and 40% of all loading variables were of lower magnitudes in both males and females after stair-climbing. Some inter-subject variation in low-back loading was attributed to body size differences, but between- and within-subject differences in movement strategies also contributed to low-back loading variability between subjects and over time. Conclusions: Results of this study suggest that characteristics of individuals, tasks performed, and physical fatigue may influence peak low-back loading demands and injury potential in firefighters. Despite considerable inter-subject variation in the internal low-back loading response to fixed external task and environmental constraints, opportunities to attenuate low-back loading demands through movement behaviour adaptations alone may be limited to only a subset of fireground activities. STUDY 2: Ankle Immobilization alters Lifting Kinematics and Kinetics – Occupational Low-Back Loading Demands and Potential for Injury. Background: Firefighters with lingering lower extremity functional impairments could be forced to move in ways that increase their potential for sustaining occupational low-back lifting injuries. The study objective was to examine the impact of unilateral ankle immobilization on lifting kinematics and kinetics. Methods: With and without their right ankle immobilized, 10 male volunteers performed laboratory-simulated occupational lifting tasks. Together with force platform data, three-dimensional kinematics of the lumbar spine, pelvis, and lower extremities were collected, and a three-dimensional dynamic biomechanical model was used to calculate peak low-back compression and shear loading demands. Results: In comparison to the unaffected conditions, ankle immobilization resulted in less knee (p-values between 0.0004 and 0.0697) and greater lumbar spine (p-values between 0.0006 and 0.3491) sagittal motion when lifting. Associated with this compensatory movement strategy were greater L4/L5 anterior/posterior reaction shear forces (p-values between 0.0009 and 0.2450). However, in a few cases where individual compensatory movement strategies differed from the “group” response (i.e., subjects increased their sagittal knee and hip motion on the affected side), peak L4/L5 joint compressive loads increased while the peak L4/L5 anterior-posterior shear did not change. Conclusions: Distal lower extremity joint dysfunction can alter the way in which individuals move and load their low-backs when lifting. The specific ways in which individuals compensate for personal movement constraints could alter the potential site and mechanism of occupational low-back injury. STUDY 3: FMS™ Scores and Occupational Low-Back Loading Demands – Whole-Body Movement Screening as an Ergonomic Tool? Background: Results of Study 1 suggested that a whole-body movement screen could be used to identify personal characteristics that constrain movement behaviour in ways that impact occupational low-back loading demands and injury potential. The purpose of this study was to examine if Functional Movement Screen™ (FMS) scores could be used to project the low-back loading response to lifting. Methods: Sagittally symmetric and asymmetric laboratory-based lifting tasks were performed by 15 firefighters who scored greater than 14 on the FMS (high-scorers) and 15 size-matched low-scorers (FMS < 14). A three-dimensional dynamic biomechanical model was used to calculate low-back loading demands, and lumbar spine posture was recorded when peak low-back compression was imposed. Results: Regardless of the task performed, there were no differences in peak L4/L5 joint compression (p ≥ 0.4157), anterior/posterior reaction shear (p ≥ 0.5645), or medial/lateral reaction shear (p ≥ 0.2581) loading demands between high- and low-scorers. At the instant when peak compression force was detected, lumbar spine deviation was not different between high- and low-scorers about the lateral bend (p ≥ 0.4215), axial twist (p ≥ 0.2734), or flexion/extension (p ≥ 0.1354) axes. Conclusions: Using the previously established musculoskeletal injury prediction threshold value of 14, the composite FMS score did not project the low-back loading response to lifting. Future attempts to modify or reinterpret FMS scoring are warranted given that several previous studies have revealed links between composite FMS scores and musculoskeletal complaints. STUDY 4: Movement- vs. Fitness-Centric Exercise – Firefighter Fitness, Whole-Body Movement Qualities, and Occupational Low-Back Loading Outcomes. Background: The impact of exercise on firefighter job performance and cardiorespiratory fitness has been studied extensively, but its effect on musculoskeletal loading remains less understood. The aim of this study was to compare various physical fitness, general movement quality, and low-back loading outcomes between groups of firefighters who completed fitness- or movement-centric exercise. Methods: Fifty-four firefighters participated and were assigned to a control (CON), fitness-centric exercise (FIT), or movement-centric exercise (MOV) group. Before and after 12 weeks of exercise, subjects performed a physical fitness test battery, the Functional Movement Screen™ (FMS), and laboratory-simulated firefighting tasks during which low-back loading demands were quantified. Results: FIT and MOV subjects exhibited statistically significant improvements in nearly all measures of physical fitness (i.e., body composition, cardiorespiratory capacity, muscular strength, power, endurance, and flexibility), but FMS scores and occupational low-back loading demands were not impacted in a consistent way across individuals. Conclusions: Improving physical fitness can enhance job performance and prevent cardiac events in firefighters, but it was not clear that 12 weeks of exercise would alter their occupational low-back loading demands. Given variability in individual responses, the short study duration, and limited number and nature of tasks examined, more research incorporating alternative biomechanical and statistical analyses is needed to better understand how individuals adapt to chronic exercise and what impact these adaptations have on occupational movement behaviours, low-back loading demands, and low-back loading capacity. SUMMARY and CONCLUSIONS: Results confirmed that fireground activities are potentially hazardous for low-back health, as simulated occupational low-back loading demands routinely exceeded recommended exposure limits in the studies performed. However, results also indicated that personal movement strategies – possibly influenced by body size, preference, gender, physical fatigue, or distal lower extremity joint dysfunction – could alter occupational low-back loading demands and injury potential. It could not be concluded that occupational low-back loading demands and injury potential would be consistently affected by short-term improvements in physical fitness, nor could the low-back loading response to lifting be projected by scoring above or below 14 on the Functional Movement Screen™. Future research is warranted to examine the low-back loading demands associated with performing non-fireground duties, as opportunities may exist to implement ergonomic strategies to control cumulative low-back loading exposures. Particular attention should be paid to the exercise and training practices of firefighters, as musculoskeletal injuries sustained during these activities are potentially avoidable and could reduce the capacity of the musculoskeletal system to withstand demands imposed during non-modifiable fireground operations.

BACKGROUND and OBJECTIVES: Low-back overexertion injuries represent a large proportion of fireground “strains, sprains and muscular pains” and are a leading cause of disability and early retirement in firefighters. Given the inherently hazardous and unpredictable nature of many fireground activities, it is often infeasible to implement “task-focused” ergonomic controls and there are limited options to accommodate injured firefighters. Accordingly, effective and practical “worker-focused” injury prevention approaches are needed. Toward this end, four studies were conducted to address the following global thesis objectives: 1) Examine the possible role that firefighters’ personal movement strategies could have on their occupational low-back loading demands and injury potential; and 2) Compare the effects of two different exercise approaches on firefighters’ occupational low-back loading demands and injury potential. STUDY 1: Low-Back Loading Demands during Simulated Firefighting Tasks – Inter-Subject Variation and the Impact of Fatigue and Gender. Background: Non-modifiable fireground duties are considered hazardous for low-back health, but personal movement strategies could modulate low-back loading demands and injury potential. Study objectives were to quantify low-back loading demands during simulated firefighting tasks and to examine the impact of fatigue and gender on the peak loading response. Methods: Ten men and 10 women performed a battery of laboratory-simulated firefighting tasks before and following repeated bouts of a fatiguing stair-climbing protocol. An EMG-assisted three-dimensional dynamic biomechanical model was used to compute peak L4/L5 joint forces during task performance. Results: Peak low-back loading demands varied considerably between subjects and tasks, but 70% of all loading variables examined were of greater magnitudes in male subjects and 40% of all loading variables were of lower magnitudes in both males and females after stair-climbing. Some inter-subject variation in low-back loading was attributed to body size differences, but between- and within-subject differences in movement strategies also contributed to low-back loading variability between subjects and over time. Conclusions: Results of this study suggest that characteristics of individuals, tasks performed, and physical fatigue may influence peak low-back loading demands and injury potential in firefighters. Despite considerable inter-subject variation in the internal low-back loading response to fixed external task and environmental constraints, opportunities to attenuate low-back loading demands through movement behaviour adaptations alone may be limited to only a subset of fireground activities. STUDY 2: Ankle Immobilization alters Lifting Kinematics and Kinetics – Occupational Low-Back Loading Demands and Potential for Injury. Background: Firefighters with lingering lower extremity functional impairments could be forced to move in ways that increase their potential for sustaining occupational low-back lifting injuries. The study objective was to examine the impact of unilateral ankle immobilization on lifting kinematics and kinetics. Methods: With and without their right ankle immobilized, 10 male volunteers performed laboratory-simulated occupational lifting tasks. Together with force platform data, three-dimensional kinematics of the lumbar spine, pelvis, and lower extremities were collected, and a three-dimensional dynamic biomechanical model was used to calculate peak low-back compression and shear loading demands. Results: In comparison to the unaffected conditions, ankle immobilization resulted in less knee (p-values between 0.0004 and 0.0697) and greater lumbar spine (p-values between 0.0006 and 0.3491) sagittal motion when lifting. Associated with this compensatory movement strategy were greater L4/L5 anterior/posterior reaction shear forces (p-values between 0.0009 and 0.2450). However, in a few cases where individual compensatory movement strategies differed from the “group” response (i.e., subjects increased their sagittal knee and hip motion on the affected side), peak L4/L5 joint compressive loads increased while the peak L4/L5 anterior-posterior shear did not change. Conclusions: Distal lower extremity joint dysfunction can alter the way in which individuals move and load their low-backs when lifting. The specific ways in which individuals compensate for personal movement constraints could alter the potential site and mechanism of occupational low-back injury. STUDY 3: FMS™ Scores and Occupational Low-Back Loading Demands – Whole-Body Movement Screening as an Ergonomic Tool? Background: Results of Study 1 suggested that a whole-body movement screen could be used to identify personal characteristics that constrain movement behaviour in ways that impact occupational low-back loading demands and injury potential. The purpose of this study was to examine if Functional Movement Screen™ (FMS) scores could be used to project the low-back loading response to lifting. Methods: Sagittally symmetric and asymmetric laboratory-based lifting tasks were performed by 15 firefighters who scored greater than 14 on the FMS (high-scorers) and 15 size-matched low-scorers (FMS < 14). A three-dimensional dynamic biomechanical model was used to calculate low-back loading demands, and lumbar spine posture was recorded when peak low-back compression was imposed. Results: Regardless of the task performed, there were no differences in peak L4/L5 joint compression (p ≥ 0.4157), anterior/posterior reaction shear (p ≥ 0.5645), or medial/lateral reaction shear (p ≥ 0.2581) loading demands between high- and low-scorers. At the instant when peak compression force was detected, lumbar spine deviation was not different between high- and low-scorers about the lateral bend (p ≥ 0.4215), axial twist (p ≥ 0.2734), or flexion/extension (p ≥ 0.1354) axes. Conclusions: Using the previously established musculoskeletal injury prediction threshold value of 14, the composite FMS score did not project the low-back loading response to lifting. Future attempts to modify or reinterpret FMS scoring are warranted given that several previous studies have revealed links between composite FMS scores and musculoskeletal complaints. STUDY 4: Movement- vs. Fitness-Centric Exercise – Firefighter Fitness, Whole-Body Movement Qualities, and Occupational Low-Back Loading Outcomes. Background: The impact of exercise on firefighter job performance and cardiorespiratory fitness has been studied extensively, but its effect on musculoskeletal loading remains less understood. The aim of this study was to compare various physical fitness, general movement quality, and low-back loading outcomes between groups of firefighters who completed fitness- or movement-centric exercise. Methods: Fifty-four firefighters participated and were assigned to a control (CON), fitness-centric exercise (FIT), or movement-centric exercise (MOV) group. Before and after 12 weeks of exercise, subjects performed a physical fitness test battery, the Functional Movement Screen™ (FMS), and laboratory-simulated firefighting tasks during which low-back loading demands were quantified. Results: FIT and MOV subjects exhibited statistically significant improvements in nearly all measures of physical fitness (i.e., body composition, cardiorespiratory capacity, muscular strength, power, endurance, and flexibility), but FMS scores and occupational low-back loading demands were not impacted in a consistent way across individuals. Conclusions: Improving physical fitness can enhance job performance and prevent cardiac events in firefighters, but it was not clear that 12 weeks of exercise would alter their occupational low-back loading demands. Given variability in individual responses, the short study duration, and limited number and nature of tasks examined, more research incorporating alternative biomechanical and statistical analyses is needed to better understand how individuals adapt to chronic exercise and what impact these adaptations have on occupational movement behaviours, low-back loading demands, and low-back loading capacity. SUMMARY and CONCLUSIONS: Results confirmed that fireground activities are potentially hazardous for low-back health, as simulated occupational low-back loading demands routinely exceeded recommended exposure limits in the studies performed. However, results also indicated that personal movement strategies – possibly influenced by body size, preference, gender, physical fatigue, or distal lower extremity joint dysfunction – could alter occupational low-back loading demands and injury potential. It could not be concluded that occupational low-back loading demands and injury potential would be consistently affected by short-term improvements in physical fitness, nor could the low-back loading response to lifting be projected by scoring above or below 14 on the Functional Movement Screen™. Future research is warranted to examine the low-back loading demands associated with performing non-fireground duties, as opportunities may exist to implement ergonomic strategies to control cumulative low-back loading exposures. Particular attention should be paid to the exercise and training practices of firefighters, as musculoskeletal injuries sustained during these activities are potentially avoidable and could reduce the capacity of the musculoskeletal system to withstand demands imposed during non-modifiable fireground operations.

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