A holistic investigation of amateur batters performance responses to a century protocol: a focused cognitive perspective
- Authors: Goble, David
- Date: 2017
- Subjects: Cricket -- Batting -- Physiological aspects , Cricket players -- Physiology , Cricket players -- Health and hygiene , Cognition -- Testing , Neurophysiology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/40725 , vital:25020
- Description: No cognitive study has implemented an exercise modality that requires both physical effort and cognitive control, therefore, the effects of such exercise are unknown. Additionally, no studies have investigated how prolonged batting impacts cognitive functioning nor how physical responses and cognitive functioning are related while batting. At intensities of 6070 percent heart rate maximum, acute and prolonged bouts of physical activity have been shown to improve cognitive functioning. At higher intensities, the beneficial effects are minimal and in some cases performance is impaired. Therefore, the aim of this investigation was to determine how prolonged intermittent batting (a task that requires high muscular and cardiovascular loads but also continuous cognitive control) affects cognitive, physiological, physical and biophysical responses in amateur batters. Further aims included to test the reliability of the method employed in assessing these responses. To answer this question, the investigation was separated into three studies: phase 1 (a large-scale pilot) and phase 2 and 3 (a repeated measures test-retest hypothesis). In each phase, batters completed the 30 over BATEX simulation, which replicated the demands of scoring a one-day international century. To establish physiological, physical and perceptual strain; heart rate, sprint times and perceived exertion data were collected each over. Changes in body mass over time were compared to determine the effects of fluid loss on cognitive performance. Before, during and after the simulation, psychomotor function, visual attention, working memory, visual learning and memory as well as executive functions were assessed (CogState brief test battery). During cognitive assessments, heart rate and heart rate variability parameters were sampled so that autonomic modulation of the heart could be determined. The methodological differences between phase 1 and phase 2 and 3, were (respectively); the frequency of cognitive assessments (five vs. three), the samples used (15 schoolboy vs. 16 academy batters), hydration protocols (250ml of Energade vs. water ad libitum) and a singular change in a physical dependent variable (batting accuracy vs. vertical jump). In schoolboy and academy batters, the prolonged batting simulation placed significant strain on the cardiovascular and muscular subsystems; increasing heart rate (p<0.01), decreasing body mass (p<0.01) and deteriorating sprint performance (p<0.01) over time. In each sample, batters’ perceived exertion increased significantly (p<0.01) and exertion was highest in the final over of the protocol. Interestingly, the changes in cardiovascular and muscular responses were larger in schoolboy batters. While the cognitive performance decrements over time were not significant in academy batters (p>0.05; d<0.2), the magnitude of impairment in psychomotor function (p>0.05; d = 0.37), visual attention (p>0.05; d = 0.56), working memory (p>0.05; d = 0.61) and executive function (p>0.05; d = 0.58) was larger in schoolboy batters. In both samples, the simulation altered the modulation of heart rate significantly. Heart rate variability decreased linearly with time spent batting (p<0.01; d>0.8). During cognitive assessments, heart rate variability increased with time-on-task, where responses were significantly higher (p<0.05) in the last task of the battery compared to the first. Importantly, the results of the retest phase were the same as in the test phase and only two condition effects were observed; (i) heart rate (retest lower: p<0.04;d = 0.39), (ii) body mass (retest lower: p<0.03;d = 0.09). A task-related condition effect in heart rate variability (PNN30) was also observed (retest higher: p<0.03; d = not calculated). Resultantly, the test-retest reliability of phase 2 and 3 was high. The results indicate that prolonged intermittent batting at an intensity of 64-77 %HRmax impaired cognitive functioning in amateur batters. However, the cardiovascular and muscular strain induced by prolonged intermittent batting and its effects on cognitive functioning are mediated by intrinsic and extrinsic factors (age, training status, playing experience and hydration). Therefore, while prolonged batting has similar effects on cognitive functioning as acute bouts of physical activity, they do not share the same relationship. The author hypothesises that the continuous cognitive component inherent in prolonged batting mitigates the beneficial effects of physical activity, as demonstrated previously. Future research is needed to elucidate this relationship. Additionally, player experience affects the way in which batters regulate performance while batting; which also affects the rate of and magnitude of impairment during batting. Finally, the methodological limitations of this study provide direction for future research into batting.
- Full Text:
- Authors: Goble, David
- Date: 2017
- Subjects: Cricket -- Batting -- Physiological aspects , Cricket players -- Physiology , Cricket players -- Health and hygiene , Cognition -- Testing , Neurophysiology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/40725 , vital:25020
- Description: No cognitive study has implemented an exercise modality that requires both physical effort and cognitive control, therefore, the effects of such exercise are unknown. Additionally, no studies have investigated how prolonged batting impacts cognitive functioning nor how physical responses and cognitive functioning are related while batting. At intensities of 6070 percent heart rate maximum, acute and prolonged bouts of physical activity have been shown to improve cognitive functioning. At higher intensities, the beneficial effects are minimal and in some cases performance is impaired. Therefore, the aim of this investigation was to determine how prolonged intermittent batting (a task that requires high muscular and cardiovascular loads but also continuous cognitive control) affects cognitive, physiological, physical and biophysical responses in amateur batters. Further aims included to test the reliability of the method employed in assessing these responses. To answer this question, the investigation was separated into three studies: phase 1 (a large-scale pilot) and phase 2 and 3 (a repeated measures test-retest hypothesis). In each phase, batters completed the 30 over BATEX simulation, which replicated the demands of scoring a one-day international century. To establish physiological, physical and perceptual strain; heart rate, sprint times and perceived exertion data were collected each over. Changes in body mass over time were compared to determine the effects of fluid loss on cognitive performance. Before, during and after the simulation, psychomotor function, visual attention, working memory, visual learning and memory as well as executive functions were assessed (CogState brief test battery). During cognitive assessments, heart rate and heart rate variability parameters were sampled so that autonomic modulation of the heart could be determined. The methodological differences between phase 1 and phase 2 and 3, were (respectively); the frequency of cognitive assessments (five vs. three), the samples used (15 schoolboy vs. 16 academy batters), hydration protocols (250ml of Energade vs. water ad libitum) and a singular change in a physical dependent variable (batting accuracy vs. vertical jump). In schoolboy and academy batters, the prolonged batting simulation placed significant strain on the cardiovascular and muscular subsystems; increasing heart rate (p<0.01), decreasing body mass (p<0.01) and deteriorating sprint performance (p<0.01) over time. In each sample, batters’ perceived exertion increased significantly (p<0.01) and exertion was highest in the final over of the protocol. Interestingly, the changes in cardiovascular and muscular responses were larger in schoolboy batters. While the cognitive performance decrements over time were not significant in academy batters (p>0.05; d<0.2), the magnitude of impairment in psychomotor function (p>0.05; d = 0.37), visual attention (p>0.05; d = 0.56), working memory (p>0.05; d = 0.61) and executive function (p>0.05; d = 0.58) was larger in schoolboy batters. In both samples, the simulation altered the modulation of heart rate significantly. Heart rate variability decreased linearly with time spent batting (p<0.01; d>0.8). During cognitive assessments, heart rate variability increased with time-on-task, where responses were significantly higher (p<0.05) in the last task of the battery compared to the first. Importantly, the results of the retest phase were the same as in the test phase and only two condition effects were observed; (i) heart rate (retest lower: p<0.04;d = 0.39), (ii) body mass (retest lower: p<0.03;d = 0.09). A task-related condition effect in heart rate variability (PNN30) was also observed (retest higher: p<0.03; d = not calculated). Resultantly, the test-retest reliability of phase 2 and 3 was high. The results indicate that prolonged intermittent batting at an intensity of 64-77 %HRmax impaired cognitive functioning in amateur batters. However, the cardiovascular and muscular strain induced by prolonged intermittent batting and its effects on cognitive functioning are mediated by intrinsic and extrinsic factors (age, training status, playing experience and hydration). Therefore, while prolonged batting has similar effects on cognitive functioning as acute bouts of physical activity, they do not share the same relationship. The author hypothesises that the continuous cognitive component inherent in prolonged batting mitigates the beneficial effects of physical activity, as demonstrated previously. Future research is needed to elucidate this relationship. Additionally, player experience affects the way in which batters regulate performance while batting; which also affects the rate of and magnitude of impairment during batting. Finally, the methodological limitations of this study provide direction for future research into batting.
- Full Text:
Appropriate integration of workers with physical limitations into a manual workplace – development of an assessment tool
- Authors: Pearson, Jessie T
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/8209 , vital:21368
- Description: Background: People with physical limitations can contribute significantly to society and the economy, however, barriers to full and effective participation in the labour market often hinder decent employment. In light of this, placement decisions of impaired workers should be based on detailed information of the nature of the jobs available, as well as individual capabilities of the worker. An ergonomics approach to design attempts to achieve an appropriate balance between the capabilities of the worker and the requirements of the task and uses this balance to improve productivity and encourage physical and mental well-being, job satisfaction and safety. A specific analysis tool which can be applied to various workplaces and jobs, and provide information for decisions regarding placement of physically limited workers, will help to increase the percentage of correct placement in an appropriate workplace, resulting in optimum productivity and worker safety. Methods: An assessment tool which allows matching of job requirements and worker capabilities was developed based on a theoretical framework from Mattison and Goebel (2007), as well as principles defined by Almgren and Schaurig (2012) and Demura and Nakada (2010). The tool assesses range of motion, force and time components of the physical requirements of different tasks involved in the job, as well as movement capabilities and limitations of the worker. The tool was pilot tested in a case study with an above the knee amputee working at a research facility. Results: The tool successfully provided information regarding the matching of the work to the identified job. The output of the tool highlighted two tasks which would place the worker at risk due to physical requirements of the tasks being greater than movement capabilities of the worker. These tasks need to be further investigated to determine if accommodations can be made to assist the worker in safely performing the task, or if the job is not suitable for the worker. Conclusions: The tool developed was useful in providing information to inform appropriate placement of the physically limited worker. Further research needs to be done to validate and determine reliability of the tool.
- Full Text:
- Authors: Pearson, Jessie T
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/8209 , vital:21368
- Description: Background: People with physical limitations can contribute significantly to society and the economy, however, barriers to full and effective participation in the labour market often hinder decent employment. In light of this, placement decisions of impaired workers should be based on detailed information of the nature of the jobs available, as well as individual capabilities of the worker. An ergonomics approach to design attempts to achieve an appropriate balance between the capabilities of the worker and the requirements of the task and uses this balance to improve productivity and encourage physical and mental well-being, job satisfaction and safety. A specific analysis tool which can be applied to various workplaces and jobs, and provide information for decisions regarding placement of physically limited workers, will help to increase the percentage of correct placement in an appropriate workplace, resulting in optimum productivity and worker safety. Methods: An assessment tool which allows matching of job requirements and worker capabilities was developed based on a theoretical framework from Mattison and Goebel (2007), as well as principles defined by Almgren and Schaurig (2012) and Demura and Nakada (2010). The tool assesses range of motion, force and time components of the physical requirements of different tasks involved in the job, as well as movement capabilities and limitations of the worker. The tool was pilot tested in a case study with an above the knee amputee working at a research facility. Results: The tool successfully provided information regarding the matching of the work to the identified job. The output of the tool highlighted two tasks which would place the worker at risk due to physical requirements of the tasks being greater than movement capabilities of the worker. These tasks need to be further investigated to determine if accommodations can be made to assist the worker in safely performing the task, or if the job is not suitable for the worker. Conclusions: The tool developed was useful in providing information to inform appropriate placement of the physically limited worker. Further research needs to be done to validate and determine reliability of the tool.
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Assessing the physical fitness level of children with intellectual disability in the Grahamstown region of the Eastern Cape, and subsequently designing, implementing and evaluating the efficacy of an exercise intervention
- Authors: Parsons, Samantha Lee
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/19723 , vital:22478
- Description: Background: Extensive research has addressed physical fitness as an agent in promoting health and well-being; however, there is little research on this topic for special populations, such as individuals with intellectual disability and even less relating to the South African context. Children with intellectual disability attending special need schools in disadvantaged communities in the Eastern Cape have lacked the opportunity to participate in structured physical education programs. Implementing a solution to this problem was seen to be a challenge, due to the lack of informative research and available data. Aims: The purpose of this research was two-fold; firstly, it aimed to identify the physical fitness levels of the intellectually disabled children in the Grahamstown region of the Eastern Cape province of South Africa; and secondly, it aimed to implement and evaluate the efficacy of an exercise intervention programme on physical fitness in a local school for children with intellectual disability. Phase 1: The descriptive study compared basic anthropometric as well as physical fitness measures from a sample of participants with intellectual disability (n=29) with a comparable sample of typically developed children (n=25). There were 15 males and 14 females in the intellectually disabled sample group, with an average age of 10.69 ± 1.26 years, and the typically developed sample had 13 males and 12 females, with an average age of 10.51 ± 0.74 years. The anthropometric measures included stature and mass; while the health-related physical fitness components included cardiorespiratory endurance, muscular endurance, strength, body composition, and flexibility; and the skill-related physical fitness components were balance, agility, speed, power, coordination and reaction time. The results revealed that the children with intellectual disability were significantly shorter in stature and lighter in mass (p <0.001) compared to their typically developed peers. Muscular endurance and strength, balance, speed, power, coordination and reaction time were poorer among those with intellectual disabilities (p <0.05). Cardiorespiratory endurance, flexibility and agility were similar between groups. Results of the correlation analyses determined significant (p <0.05) relationships between certain health-related and/or skill-related physical fitness components, which were instrumental for selecting measures for Phase 2. The physical fitness components that had the most significant (p <0.05) correlations were speed with five significant correlations, both muscular endurance and balance with six, coordination with seven, and power with eight significant correlations of the eleven physical fitness components. The comparative results, in conjunction with the correlations, determined that the most suitable physical fitness components to be implemented in the exercise intervention for Phase 2 were muscular endurance, balance, and power. Phase 2: The intervention study was a case-control study (intervention group: n = 16; control group: n = 15), whereby the intervention group was exposed to an 8-week multi-modal exercise intervention training muscular endurance, balance and power. Pre-and post-intervention measures were performed using the same eleven physical fitness tests as in Phase 1. The interaction effects and effect sizes were determined and the results showed significant improvements and large effect sizes for the intervention group’s performance of muscular endurance (p=0.026; d=0.617) and power (p<0.000; d=0.999), whereas no significant changes were found for balance. Furthermore, the exercise intervention also impacted the overall level of physical fitness, as significant changes were found for cardiorespiratory endurance (p<0.001; d=0.98), strength (p=0.021; d=0.654) and flexibility (p=0.032; d=586). In conclusion, the exercise intervention was effective for improving the intellectually disabled participants’ muscular endurance and power but not found effective for balance.
- Full Text:
- Authors: Parsons, Samantha Lee
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/19723 , vital:22478
- Description: Background: Extensive research has addressed physical fitness as an agent in promoting health and well-being; however, there is little research on this topic for special populations, such as individuals with intellectual disability and even less relating to the South African context. Children with intellectual disability attending special need schools in disadvantaged communities in the Eastern Cape have lacked the opportunity to participate in structured physical education programs. Implementing a solution to this problem was seen to be a challenge, due to the lack of informative research and available data. Aims: The purpose of this research was two-fold; firstly, it aimed to identify the physical fitness levels of the intellectually disabled children in the Grahamstown region of the Eastern Cape province of South Africa; and secondly, it aimed to implement and evaluate the efficacy of an exercise intervention programme on physical fitness in a local school for children with intellectual disability. Phase 1: The descriptive study compared basic anthropometric as well as physical fitness measures from a sample of participants with intellectual disability (n=29) with a comparable sample of typically developed children (n=25). There were 15 males and 14 females in the intellectually disabled sample group, with an average age of 10.69 ± 1.26 years, and the typically developed sample had 13 males and 12 females, with an average age of 10.51 ± 0.74 years. The anthropometric measures included stature and mass; while the health-related physical fitness components included cardiorespiratory endurance, muscular endurance, strength, body composition, and flexibility; and the skill-related physical fitness components were balance, agility, speed, power, coordination and reaction time. The results revealed that the children with intellectual disability were significantly shorter in stature and lighter in mass (p <0.001) compared to their typically developed peers. Muscular endurance and strength, balance, speed, power, coordination and reaction time were poorer among those with intellectual disabilities (p <0.05). Cardiorespiratory endurance, flexibility and agility were similar between groups. Results of the correlation analyses determined significant (p <0.05) relationships between certain health-related and/or skill-related physical fitness components, which were instrumental for selecting measures for Phase 2. The physical fitness components that had the most significant (p <0.05) correlations were speed with five significant correlations, both muscular endurance and balance with six, coordination with seven, and power with eight significant correlations of the eleven physical fitness components. The comparative results, in conjunction with the correlations, determined that the most suitable physical fitness components to be implemented in the exercise intervention for Phase 2 were muscular endurance, balance, and power. Phase 2: The intervention study was a case-control study (intervention group: n = 16; control group: n = 15), whereby the intervention group was exposed to an 8-week multi-modal exercise intervention training muscular endurance, balance and power. Pre-and post-intervention measures were performed using the same eleven physical fitness tests as in Phase 1. The interaction effects and effect sizes were determined and the results showed significant improvements and large effect sizes for the intervention group’s performance of muscular endurance (p=0.026; d=0.617) and power (p<0.000; d=0.999), whereas no significant changes were found for balance. Furthermore, the exercise intervention also impacted the overall level of physical fitness, as significant changes were found for cardiorespiratory endurance (p<0.001; d=0.98), strength (p=0.021; d=0.654) and flexibility (p=0.032; d=586). In conclusion, the exercise intervention was effective for improving the intellectually disabled participants’ muscular endurance and power but not found effective for balance.
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Cardiovascular disease risk in Black and Caucasian females: an Eastern Cape sample
- Authors: Remsing, Sandra Claudia
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/40737 , vital:25021
- Description: The purpose of this study was to investigate cardiovascular disease risk in Black and Caucasian urban working females of the Makana region of the Eastern Cape. One- hundred and sixty six age-matched urban-working individuals (Black n = 88; Caucasian n = 78) voluntarily participated in this cross-sectional study. Cardiovascular disease risk was assessed in four categories: 1) obesity, classified as ‘morphological risk’, 2) blood pressure, classified as ‘cardiovascular risk’, 3) diet, physical activity, smoking, and alcohol consumption, classified as ‘lifestyle risk’, and 4) education and income, classified as ‘socioeconomic factors’. Results showed that Black females were significantly (p<0.01) heavier than Caucasian females and categorized as ‘obese’ according to BMI classifications (31.19 ± 8.09 kg.m2 and 25.90 ±4.67 kg.m2, respectively). Black females also presented with significantly (p<0.01) higher waist circumferences and waist-to-stature ratios, further confirming the obesity prevalence in this group. When accounting for those who were on anti-hypertensive mediation, Black females additionally presented with significantly (p<0.05) higher blood pressure, categorizing them as ‘pre-hypertensive’ (MAP = 98 ± 16 mmHg and 85 ± 11 mmHg, respectively). These results therefore placed Black females at increased cardiovascular disease risk compared to Caucasian females. With respect to lifestyle factors, Black females consumed significantly (p<0.05) more kilojoules carbohydrates, and total sugar than Caucasian females, and expended more physical activity MET- minutes per week (2688.86 ± 1486.56 MET-minutes and 1828.27 ± 2238.10 MET- minutes, respectively). However, reduced validity of physical activity data as well as poor dietary recall limited the interpretations of these findings. In addition, despite significant differences between smoking and alcohol consumption between groups, the majority of both Black and Caucasian females reported being non-smokers and consumed alcohol minimally. Thus, these were concluded to be unlikely contributors to cardiovascular disease risk in these samples. Socioeconomic results nevertheless expectedly showed that Black females were significantly (p<0.05) less educated, and subsequently earned lower incomes. It was thus concluded that this may be a likely contributor to higher cardiovascular risk in Black females. Future recommendations include the incorporation of exercise intensity measures as well as objective measures of habitual diet. This is in order to get a clearer understanding of the impact of these lifestyle factors on cardiovascular disease risk.
- Full Text:
- Authors: Remsing, Sandra Claudia
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/40737 , vital:25021
- Description: The purpose of this study was to investigate cardiovascular disease risk in Black and Caucasian urban working females of the Makana region of the Eastern Cape. One- hundred and sixty six age-matched urban-working individuals (Black n = 88; Caucasian n = 78) voluntarily participated in this cross-sectional study. Cardiovascular disease risk was assessed in four categories: 1) obesity, classified as ‘morphological risk’, 2) blood pressure, classified as ‘cardiovascular risk’, 3) diet, physical activity, smoking, and alcohol consumption, classified as ‘lifestyle risk’, and 4) education and income, classified as ‘socioeconomic factors’. Results showed that Black females were significantly (p<0.01) heavier than Caucasian females and categorized as ‘obese’ according to BMI classifications (31.19 ± 8.09 kg.m2 and 25.90 ±4.67 kg.m2, respectively). Black females also presented with significantly (p<0.01) higher waist circumferences and waist-to-stature ratios, further confirming the obesity prevalence in this group. When accounting for those who were on anti-hypertensive mediation, Black females additionally presented with significantly (p<0.05) higher blood pressure, categorizing them as ‘pre-hypertensive’ (MAP = 98 ± 16 mmHg and 85 ± 11 mmHg, respectively). These results therefore placed Black females at increased cardiovascular disease risk compared to Caucasian females. With respect to lifestyle factors, Black females consumed significantly (p<0.05) more kilojoules carbohydrates, and total sugar than Caucasian females, and expended more physical activity MET- minutes per week (2688.86 ± 1486.56 MET-minutes and 1828.27 ± 2238.10 MET- minutes, respectively). However, reduced validity of physical activity data as well as poor dietary recall limited the interpretations of these findings. In addition, despite significant differences between smoking and alcohol consumption between groups, the majority of both Black and Caucasian females reported being non-smokers and consumed alcohol minimally. Thus, these were concluded to be unlikely contributors to cardiovascular disease risk in these samples. Socioeconomic results nevertheless expectedly showed that Black females were significantly (p<0.05) less educated, and subsequently earned lower incomes. It was thus concluded that this may be a likely contributor to higher cardiovascular risk in Black females. Future recommendations include the incorporation of exercise intensity measures as well as objective measures of habitual diet. This is in order to get a clearer understanding of the impact of these lifestyle factors on cardiovascular disease risk.
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The effect of different seating conditions, in aircrafts, on passenger comfort and the use of cabin space
- Authors: Olley, Emma-Jane
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/19734 , vital:22479
- Description: Although aircraft cabin design has improved over the years, passengers continue to complain about sitting discomfort whilst flying. These complaints are often centred on the cramped and restricted seating conditions. Whilst passenger comfort is important, in order for airline companies to attract and retain customers, it is also important to design for cabin space needs. Denel Aviation intends to build a South African Regional Aircraft (SARA) that will fly point-to-point, linking regional centres and intends to design aircraft seats that not only optimise passenger comfort, but which also save cabin space. The aim of this investigation was two-fold. The first aim was to determine how aircraft backrest angle affected passenger comfort, ease of seat access, perceived restriction and legroom, with different seat pan angles and seat heights. The second aim was to determine whether passenger comfort was affected with the most preferred backrest angle for each seat pan angle and seat height. Determining how seat pan angle and seat height affect the preferred angle of the backrest was considered important as Denel intend to use aircraft seats with a non-adjustable backrest angle. For this study, 80 participants were recruited from Rhodes University and the general Grahamstown population. The participants consisted of 40 males and 40 females and were not limited by race, ethnicity or culture. The participants were classified into two age groups; 18-30 years of age and 31-60 years of age. Participant stature, body mass, BMI and lower leg length was recorded to determine the effect these factors had on sitting comfort when the participants were seated in different seating conditions. From the results obtained, it was found that, by altering seat height, seat pan angle, and backrest angle, passenger comfort can be optimised. Furthermore, it was found that certain combinations of seat height, seat pan angle and backrest angle are more beneficial with regards to saving aircraft cabin space. However, this means that a compromise needs to be found for SARA as passenger comfort needs to be optimised, whilst decreasing the use of cabin space to reduce costs.
- Full Text:
- Authors: Olley, Emma-Jane
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/19734 , vital:22479
- Description: Although aircraft cabin design has improved over the years, passengers continue to complain about sitting discomfort whilst flying. These complaints are often centred on the cramped and restricted seating conditions. Whilst passenger comfort is important, in order for airline companies to attract and retain customers, it is also important to design for cabin space needs. Denel Aviation intends to build a South African Regional Aircraft (SARA) that will fly point-to-point, linking regional centres and intends to design aircraft seats that not only optimise passenger comfort, but which also save cabin space. The aim of this investigation was two-fold. The first aim was to determine how aircraft backrest angle affected passenger comfort, ease of seat access, perceived restriction and legroom, with different seat pan angles and seat heights. The second aim was to determine whether passenger comfort was affected with the most preferred backrest angle for each seat pan angle and seat height. Determining how seat pan angle and seat height affect the preferred angle of the backrest was considered important as Denel intend to use aircraft seats with a non-adjustable backrest angle. For this study, 80 participants were recruited from Rhodes University and the general Grahamstown population. The participants consisted of 40 males and 40 females and were not limited by race, ethnicity or culture. The participants were classified into two age groups; 18-30 years of age and 31-60 years of age. Participant stature, body mass, BMI and lower leg length was recorded to determine the effect these factors had on sitting comfort when the participants were seated in different seating conditions. From the results obtained, it was found that, by altering seat height, seat pan angle, and backrest angle, passenger comfort can be optimised. Furthermore, it was found that certain combinations of seat height, seat pan angle and backrest angle are more beneficial with regards to saving aircraft cabin space. However, this means that a compromise needs to be found for SARA as passenger comfort needs to be optimised, whilst decreasing the use of cabin space to reduce costs.
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The effect of submersion in water and breathing modality (assisted breathing and apnea) on different stages of the information processing chain
- Authors: Goodenough, Luke Brian
- Date: 2017
- Subjects: Deep diving -- Physiological aspects , Scuba diving -- Physiological aspects , Apnea , Cognition -- Testing , Neurophysiology , Underwater breathing apparatus
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/7448 , vital:21261
- Description: Limited research has explored the impact of working underwater on the cognitive functioning of divers and even less has focused on the effect of breathing modality (assisted breathing and apnea) underwater. Research on the effect of submersion in water and apnea on cognitive performance is also very limited. As a result, the purpose of this study was to determine the effect of submersion in water and breathing modality on different stages of the information processing chain. This was achieved by testing participants in a laboratory setting under three conditions; on land, underwater with assisted breathing and underwater in apnea. Five different tests were used to determine which aspects of cognitive functioning were impaired in which condition. The recognition task result in the assisted breathing condition was significantly faster (p=0.04) but less accurate (p=0.01) than on land. The memory task was significantly (p=0.042) worse in terms of speed in the apnea condition compared to land, however accuracy was not affected. Performance in the visual detection task was impacted on in both underwater conditions compared to land with speed and accuracy being significantly worse (p<0.01) in the underwater conditions. These results indicate that simple tasks, (reaction time and tracking task) are not affected by condition whereas more complex tasks are. For tasks where an effect was found for only one condition, the effect was attributed to a specific aspect of that condition; either the breath hold or assisted breathing component of the condition. For tasks that were found to be affected in both underwater conditions, the effect was attributed to the actual submersion in water. The effect of the different conditions and the nature of the task they impact on should be considered for underwater work places as the general equipment used may impact on the quality of observations that are made.
- Full Text:
- Authors: Goodenough, Luke Brian
- Date: 2017
- Subjects: Deep diving -- Physiological aspects , Scuba diving -- Physiological aspects , Apnea , Cognition -- Testing , Neurophysiology , Underwater breathing apparatus
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/7448 , vital:21261
- Description: Limited research has explored the impact of working underwater on the cognitive functioning of divers and even less has focused on the effect of breathing modality (assisted breathing and apnea) underwater. Research on the effect of submersion in water and apnea on cognitive performance is also very limited. As a result, the purpose of this study was to determine the effect of submersion in water and breathing modality on different stages of the information processing chain. This was achieved by testing participants in a laboratory setting under three conditions; on land, underwater with assisted breathing and underwater in apnea. Five different tests were used to determine which aspects of cognitive functioning were impaired in which condition. The recognition task result in the assisted breathing condition was significantly faster (p=0.04) but less accurate (p=0.01) than on land. The memory task was significantly (p=0.042) worse in terms of speed in the apnea condition compared to land, however accuracy was not affected. Performance in the visual detection task was impacted on in both underwater conditions compared to land with speed and accuracy being significantly worse (p<0.01) in the underwater conditions. These results indicate that simple tasks, (reaction time and tracking task) are not affected by condition whereas more complex tasks are. For tasks where an effect was found for only one condition, the effect was attributed to a specific aspect of that condition; either the breath hold or assisted breathing component of the condition. For tasks that were found to be affected in both underwater conditions, the effect was attributed to the actual submersion in water. The effect of the different conditions and the nature of the task they impact on should be considered for underwater work places as the general equipment used may impact on the quality of observations that are made.
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The effect of total standing duration during sit-stand regimes on cognitive performance, rating of perceived exertion and heart rate frequency
- Authors: Berndt, Ethan
- Date: 2017
- Subjects: Standing position , Sedentary behavior , Work environment , Employee health promotion , Office furniture -- Design , Industrial hygiene , Employees -- Health risk assessment , Human engineering
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/7433 , vital:21260
- Description: Although there may be numerous health benefits of sit-stand workstations, the effects of sedentary or non-sedentary work configurations on cognitive performance and executive function remain unclear (Bantoft et al., 2016). It is essential to determine any performance effects of these different work configurations; as improvements in the workplace, working posture and discomfort need to be justified in terms of improvements (or no deterioration) in work performance (Liao and Drury, 2000). The aim of the current research was to investigate the effect of two sit-stand regimes differing in total standing duration, on cognitive task performance, physiological responses and subjective ratings of perceived exertion. This laboratory based investigation incorporated a repeated measures design, where a test battery was utilized. Three experimental conditions were tested during three separate testing sessions by 30 participants. Condition 2 (15 minutes standing, followed by 45 minutes seated) and Condition 3 (15 minutes seated, followed by 15 minutes standing, followed by 15 minutes seated, followed by 15 minutes standing) were compared to each other and Condition 1 (60 minutes seated). The findings of this study show that even though the two different sit-stand regimes did not result in a significant impact on cognitive task performance, an immediate postural effect for psychomotor response time and a delayed postural effect for working memory were found. The participants perceived Condition 3 as the most physically exerting condition. Heart rate frequency was not significantly different between the conditions, but the immediate seated posture had a significantly lower heart rate frequency compared to the standing posture; indicating that being seated elicited lower energy expenditure compared to standing. Heart rate frequency while standing had a greater degree of variation compared to being seated. Taking the findings of this study into account, it is recommended that: one should be seated while performing this type of working memory task; that one should be standing while performing this type of psychomotor task; that the recommendation that implementing standing at work can be used as a blanket strategy to increase energy expenditure in all individuals needs to be explored further and that individual differences may impact energy expenditure.
- Full Text:
- Authors: Berndt, Ethan
- Date: 2017
- Subjects: Standing position , Sedentary behavior , Work environment , Employee health promotion , Office furniture -- Design , Industrial hygiene , Employees -- Health risk assessment , Human engineering
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/7433 , vital:21260
- Description: Although there may be numerous health benefits of sit-stand workstations, the effects of sedentary or non-sedentary work configurations on cognitive performance and executive function remain unclear (Bantoft et al., 2016). It is essential to determine any performance effects of these different work configurations; as improvements in the workplace, working posture and discomfort need to be justified in terms of improvements (or no deterioration) in work performance (Liao and Drury, 2000). The aim of the current research was to investigate the effect of two sit-stand regimes differing in total standing duration, on cognitive task performance, physiological responses and subjective ratings of perceived exertion. This laboratory based investigation incorporated a repeated measures design, where a test battery was utilized. Three experimental conditions were tested during three separate testing sessions by 30 participants. Condition 2 (15 minutes standing, followed by 45 minutes seated) and Condition 3 (15 minutes seated, followed by 15 minutes standing, followed by 15 minutes seated, followed by 15 minutes standing) were compared to each other and Condition 1 (60 minutes seated). The findings of this study show that even though the two different sit-stand regimes did not result in a significant impact on cognitive task performance, an immediate postural effect for psychomotor response time and a delayed postural effect for working memory were found. The participants perceived Condition 3 as the most physically exerting condition. Heart rate frequency was not significantly different between the conditions, but the immediate seated posture had a significantly lower heart rate frequency compared to the standing posture; indicating that being seated elicited lower energy expenditure compared to standing. Heart rate frequency while standing had a greater degree of variation compared to being seated. Taking the findings of this study into account, it is recommended that: one should be seated while performing this type of working memory task; that one should be standing while performing this type of psychomotor task; that the recommendation that implementing standing at work can be used as a blanket strategy to increase energy expenditure in all individuals needs to be explored further and that individual differences may impact energy expenditure.
- Full Text:
The effects of the type of rest breaks on return-to-task performance in semi-automated tasks with varying complexities
- Authors: Hoyi, Zandile
- Date: 2017
- Subjects: Rest periods , Rest periods -- Physiological effect , Human-robot interaction , Aeronautics -- Human factors , Human engineering , Drowsiness
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/44490 , vital:25412
- Description: Automation in the aviation industry is acknowledged as a useful tool in reducing pilot workload (Hoh, Smith & Hinton, 1987; Beringer & Harris Jr., 1999). Typically, the role of the pilot (operator) shifts from active participation in a process to a task of monitoring the system with the resumption of control should the automation ‘fail’ (Byrne & Parasuraman, 1996). Unfortunately, the skills necessary to do so would likely degrade from non-use, during this process (Landry, 2012). This project investigates the “attentional demands” for the human operator during interaction with semi-automated operations of the flight. According to Dr Abbott (1996), FAA human factors specialist, one of the problems causing disharmony between crews and their automated systems is the incorrect upset recovery, owing to the human being out-of-the-loop (OOTL) from the system. Recovery, or rather return to task, is the ability of the pilot to loop back into control, once situational awareness has been decreased due to lack of alertness and a decrease in arousal. Different types of rest tasks are commonly prescribed fatigue countermeasures in the industrial setting and have been showed to elicit beneficial effects on prolonged human performance. Understanding the effects of different rest break activity and time out-of-the-loop during semi-automated flying on return to task performance has been adequately studied, thus highlighting its importance in the context of flight safety. The present study requested participants to perform a tracking task in a laboratory where they changed from activity (30 minutes) to a break (2 vs. 30 minutes) and back to the activity (20 minutes). The task varied in the complexity of the activity (pure tracking vs. tracking plus memory plus rule-based decision making), the type of break (passive rest vs. actively supervising) and the duration of the break (2 minutes vs. 30 minutes). Performance was measured as effective response time in the tracking task and number of correct responses to secondary cognitive tasks. Physiological measures included heart rate (HR), heart rate variability (HRV- time and frequency-domain), eye blink frequency and duration. The Karolinska Sleepiness Scale was used as a subjective measure. With regards to the most appropriate rest break tasks, the study concluded that active, administrative tasks, which allowed the operator to maintain some form of situational awareness by monitoring the automated system, achieved favourable effects of being more alert than the passive rest break of being disengaged from the system. In terms of the most appropriate rest break durations, the shorter duration of being out-of-the-loop from controlling the system proved to be more advantageous than the longer out-of-the-loop duration. In looking at the workload levels of arousal, the results suggest that the higher workload level is better at maintaining the alertness of operators. This study functions as a foundational framework for future investigations around the topic of human-automation interaction, looking specifically at return-to-task performance.
- Full Text:
- Authors: Hoyi, Zandile
- Date: 2017
- Subjects: Rest periods , Rest periods -- Physiological effect , Human-robot interaction , Aeronautics -- Human factors , Human engineering , Drowsiness
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/44490 , vital:25412
- Description: Automation in the aviation industry is acknowledged as a useful tool in reducing pilot workload (Hoh, Smith & Hinton, 1987; Beringer & Harris Jr., 1999). Typically, the role of the pilot (operator) shifts from active participation in a process to a task of monitoring the system with the resumption of control should the automation ‘fail’ (Byrne & Parasuraman, 1996). Unfortunately, the skills necessary to do so would likely degrade from non-use, during this process (Landry, 2012). This project investigates the “attentional demands” for the human operator during interaction with semi-automated operations of the flight. According to Dr Abbott (1996), FAA human factors specialist, one of the problems causing disharmony between crews and their automated systems is the incorrect upset recovery, owing to the human being out-of-the-loop (OOTL) from the system. Recovery, or rather return to task, is the ability of the pilot to loop back into control, once situational awareness has been decreased due to lack of alertness and a decrease in arousal. Different types of rest tasks are commonly prescribed fatigue countermeasures in the industrial setting and have been showed to elicit beneficial effects on prolonged human performance. Understanding the effects of different rest break activity and time out-of-the-loop during semi-automated flying on return to task performance has been adequately studied, thus highlighting its importance in the context of flight safety. The present study requested participants to perform a tracking task in a laboratory where they changed from activity (30 minutes) to a break (2 vs. 30 minutes) and back to the activity (20 minutes). The task varied in the complexity of the activity (pure tracking vs. tracking plus memory plus rule-based decision making), the type of break (passive rest vs. actively supervising) and the duration of the break (2 minutes vs. 30 minutes). Performance was measured as effective response time in the tracking task and number of correct responses to secondary cognitive tasks. Physiological measures included heart rate (HR), heart rate variability (HRV- time and frequency-domain), eye blink frequency and duration. The Karolinska Sleepiness Scale was used as a subjective measure. With regards to the most appropriate rest break tasks, the study concluded that active, administrative tasks, which allowed the operator to maintain some form of situational awareness by monitoring the automated system, achieved favourable effects of being more alert than the passive rest break of being disengaged from the system. In terms of the most appropriate rest break durations, the shorter duration of being out-of-the-loop from controlling the system proved to be more advantageous than the longer out-of-the-loop duration. In looking at the workload levels of arousal, the results suggest that the higher workload level is better at maintaining the alertness of operators. This study functions as a foundational framework for future investigations around the topic of human-automation interaction, looking specifically at return-to-task performance.
- Full Text:
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