A preliminary investigation of spinal kinematics during sugar cane harvesting
- Authors: Todd, Andrew I
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6759 , http://hdl.handle.net/10962/d1009462
- Description: The sugar cane industry forms a significant portion of the South African economy, and unlike many other countries the harvesting of sugar cane in South Africa remains manual in nature. The focus of the present study was therefore on the assessment of spinal kinematics (range of motion, velocities and accelerations in all three cardinal planes) during the harvesting process. Eight workers were recruited from the Illovo Esperanza farm in Kwa-zulu Natal as subjects for the study. The experimental protocol was conducted in situ and required subjects to cut the sugar cane using specially modified knives as they would under normal harvesting conditions. The motion performance was quantified using the lumbar motion monitor (LMM), a triaxial electrogoniometer. Results indicate that the harvesting of sugar cane places excessive demands on the spine. During cutting, subjects were required to maintain the spine in a high degree of flexion throughout the task which also demonstrated significant twisting and lateral bending. Of particular concern were the high lateral velocities (ranging between 50 and 90 m.s-1), as this is a key risk factor in the development of lower back pain. It is evident from these results that new techniques of harvesting sugar cane are essential to reduce the rate of injury within this industry.
- Full Text:
- Date Issued: 2008
- Authors: Todd, Andrew I
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6759 , http://hdl.handle.net/10962/d1009462
- Description: The sugar cane industry forms a significant portion of the South African economy, and unlike many other countries the harvesting of sugar cane in South Africa remains manual in nature. The focus of the present study was therefore on the assessment of spinal kinematics (range of motion, velocities and accelerations in all three cardinal planes) during the harvesting process. Eight workers were recruited from the Illovo Esperanza farm in Kwa-zulu Natal as subjects for the study. The experimental protocol was conducted in situ and required subjects to cut the sugar cane using specially modified knives as they would under normal harvesting conditions. The motion performance was quantified using the lumbar motion monitor (LMM), a triaxial electrogoniometer. Results indicate that the harvesting of sugar cane places excessive demands on the spine. During cutting, subjects were required to maintain the spine in a high degree of flexion throughout the task which also demonstrated significant twisting and lateral bending. Of particular concern were the high lateral velocities (ranging between 50 and 90 m.s-1), as this is a key risk factor in the development of lower back pain. It is evident from these results that new techniques of harvesting sugar cane are essential to reduce the rate of injury within this industry.
- Full Text:
- Date Issued: 2008
The effects of load and gradient on hand force responses during dynamic pushing and pulling tasks
- Bennett, Anthea I, Desai, Sheena D, Todd, Andrew I, Freeland, H
- Authors: Bennett, Anthea I , Desai, Sheena D , Todd, Andrew I , Freeland, H
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6757 , http://hdl.handle.net/10962/d1009459
- Description: The limited attention afforded to push/pull activities and the motion phases (initial, sustained and ending) characteristic of these tasks has prompted a research focus in this area. The present study examined biomechanical responses in the form of hand forces during dynamic submaximal trolley pushing and pulling. Participants pushed/pulled loads of 100, 200 and 300 kg on the level (determining impact of load) or pushed 100 kg along a 12° ramp (uphill and downhill- determining impact of gradient). During level exertions significant differences (p<0.05) in hand forces occurred between loads of 100 and 200 kg, and 100 and 300 kg for initial and sustained forces but not ending forces. Values were similar for pushing and pulling at respective loads and motion phases. Strong correlations indicate that initial forces can be used to accurately estimate sustained and ending forces. Importantly, correct technique is essential in force reduction. Forces were highest during uphill initial and sustained phases and the downhill sustained phase. For the initial phase, the forces were highest during uphill pushing (86.5 ± 25.73 N); for the sustained phase, there was no difference between uphill and downhill forces but level forces were significantly lower (18.19 ± 8.09 N) than either of the other two conditions; for the ending phase, the highest forces were produced during downhill pushing (-53.34 ± 13.65N). As sustained forces equaled or exceeded initial forces for uphill and downhill efforts, consideration of sustained forces may be appropriate in determining the inherent potential risk of graded pushing.
- Full Text:
- Date Issued: 2008
- Authors: Bennett, Anthea I , Desai, Sheena D , Todd, Andrew I , Freeland, H
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6757 , http://hdl.handle.net/10962/d1009459
- Description: The limited attention afforded to push/pull activities and the motion phases (initial, sustained and ending) characteristic of these tasks has prompted a research focus in this area. The present study examined biomechanical responses in the form of hand forces during dynamic submaximal trolley pushing and pulling. Participants pushed/pulled loads of 100, 200 and 300 kg on the level (determining impact of load) or pushed 100 kg along a 12° ramp (uphill and downhill- determining impact of gradient). During level exertions significant differences (p<0.05) in hand forces occurred between loads of 100 and 200 kg, and 100 and 300 kg for initial and sustained forces but not ending forces. Values were similar for pushing and pulling at respective loads and motion phases. Strong correlations indicate that initial forces can be used to accurately estimate sustained and ending forces. Importantly, correct technique is essential in force reduction. Forces were highest during uphill initial and sustained phases and the downhill sustained phase. For the initial phase, the forces were highest during uphill pushing (86.5 ± 25.73 N); for the sustained phase, there was no difference between uphill and downhill forces but level forces were significantly lower (18.19 ± 8.09 N) than either of the other two conditions; for the ending phase, the highest forces were produced during downhill pushing (-53.34 ± 13.65N). As sustained forces equaled or exceeded initial forces for uphill and downhill efforts, consideration of sustained forces may be appropriate in determining the inherent potential risk of graded pushing.
- Full Text:
- Date Issued: 2008
Physical implications of prolonged sitting in a confined posture - a literature review
- Todd, Andrew I, Bennett, Anthea I, Christie, Candice J
- Authors: Todd, Andrew I , Bennett, Anthea I , Christie, Candice J
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6756 , http://hdl.handle.net/10962/d1009458
- Description: The main purpose of this review article was to highlight some of the physical consequences of sitting for prolonged periods in a confined setting. More specifically, the review relates this research to call centre work and where applicable comments on the limited literature relating specifically to ergonomics research within call centre settings. In particular the article explores the biomechanical stresses placed on the musculoskeletal system during prolonged sitting at a workstation, and the physiological consequences thereof. The paper then provides possible solutions to reduce the physical strain placed on these workers by looking at workstation design and work organisation emphasizing worker education and the promotion of worker well being.
- Full Text:
- Date Issued: 2007
- Authors: Todd, Andrew I , Bennett, Anthea I , Christie, Candice J
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6756 , http://hdl.handle.net/10962/d1009458
- Description: The main purpose of this review article was to highlight some of the physical consequences of sitting for prolonged periods in a confined setting. More specifically, the review relates this research to call centre work and where applicable comments on the limited literature relating specifically to ergonomics research within call centre settings. In particular the article explores the biomechanical stresses placed on the musculoskeletal system during prolonged sitting at a workstation, and the physiological consequences thereof. The paper then provides possible solutions to reduce the physical strain placed on these workers by looking at workstation design and work organisation emphasizing worker education and the promotion of worker well being.
- Full Text:
- Date Issued: 2007
Current trends in research focused on pushing and pulling : research article
- Authors: Todd, Andrew I
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6744 , http://hdl.handle.net/10962/d1009313
- Description: The purpose of this review paper is to provide a synopsis of the findings of papers on pushing and pulling; and to identify areas of contention which require further in depth analysis. It is evident from reviewing the published papers on pushing and pulling that there is a lack of consensus as to which one of these two actions has the greatest force production. The main problem is probably the lack of standardized methodology in push-pull research. Furthermore, even when similar methodologies have been used the description of postures adopted during testing by the subjects varies greatly from paper to paper. The various studies have employed different postures and also imposed different restrictions on the postures adopted during experimentation, making comparisons between findings difficult. Much emphasis has been placed on the evaluation of static pushing and pulling tasks, and there is a clear need for further research into dynamic pushing and pulling. Additionally to date the focus of much of this research has been on the biomechanical stresses placed on the body with little attention being given to the physiological cost of pushing and pulling.
- Full Text:
- Date Issued: 2005
- Authors: Todd, Andrew I
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6744 , http://hdl.handle.net/10962/d1009313
- Description: The purpose of this review paper is to provide a synopsis of the findings of papers on pushing and pulling; and to identify areas of contention which require further in depth analysis. It is evident from reviewing the published papers on pushing and pulling that there is a lack of consensus as to which one of these two actions has the greatest force production. The main problem is probably the lack of standardized methodology in push-pull research. Furthermore, even when similar methodologies have been used the description of postures adopted during testing by the subjects varies greatly from paper to paper. The various studies have employed different postures and also imposed different restrictions on the postures adopted during experimentation, making comparisons between findings difficult. Much emphasis has been placed on the evaluation of static pushing and pulling tasks, and there is a clear need for further research into dynamic pushing and pulling. Additionally to date the focus of much of this research has been on the biomechanical stresses placed on the body with little attention being given to the physiological cost of pushing and pulling.
- Full Text:
- Date Issued: 2005
Metabolic responses to various combinations of gradient, load and marching speed
- Todd, Andrew I, Scott, Patricia A
- Authors: Todd, Andrew I , Scott, Patricia A
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6751 , http://hdl.handle.net/10962/d1009331
- Description: This study examined the metabolic cost of South African soldiers carrying loads under various conditions of gradient and marching speed. Thirty-two male soldiers participated in the study. Three speed and load combinations, 4, 5 and 6 km.h[superscript (-1)] carrying of 50, 35 and 20 kg respectively, were imposed, on each of three gradients: -10%, 0% and +10%; a total of nine experimental conditions. Subjects wore standardized military uniforms and breathed into a portable ergospirometer (Metamax) for the duration of each condition. Subjects were required to march for six minutes under each condition, and metabolic responses were monitored during the third and sixth minute of each condition. The metabolic responses to the three level marching conditions showed no significant differences. Marching uphill resulted in a significant increase in metabolic demands under all three speed and load onditions. Downhill marching elicited significant decreases only under the two lighter load conditions. Downhill marching with heavy loads appears to show no reduction in metabolic demands placed on soldiers.
- Full Text:
- Date Issued: 2002
- Authors: Todd, Andrew I , Scott, Patricia A
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6751 , http://hdl.handle.net/10962/d1009331
- Description: This study examined the metabolic cost of South African soldiers carrying loads under various conditions of gradient and marching speed. Thirty-two male soldiers participated in the study. Three speed and load combinations, 4, 5 and 6 km.h[superscript (-1)] carrying of 50, 35 and 20 kg respectively, were imposed, on each of three gradients: -10%, 0% and +10%; a total of nine experimental conditions. Subjects wore standardized military uniforms and breathed into a portable ergospirometer (Metamax) for the duration of each condition. Subjects were required to march for six minutes under each condition, and metabolic responses were monitored during the third and sixth minute of each condition. The metabolic responses to the three level marching conditions showed no significant differences. Marching uphill resulted in a significant increase in metabolic demands under all three speed and load onditions. Downhill marching elicited significant decreases only under the two lighter load conditions. Downhill marching with heavy loads appears to show no reduction in metabolic demands placed on soldiers.
- Full Text:
- Date Issued: 2002
Enhancing military efficiency : a South African perspective
- Christie, Candice J, Todd, Andrew I
- Authors: Christie, Candice J , Todd, Andrew I
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:6749 , http://hdl.handle.net/10962/d1009329
- Description: While extensive military research has been conducted in developed countries, very little work has been done on soldiers in industrially developing countries (IDCs). Although many aspects of marching are similar around the globe, the challenges facing soldiers in IDCs, and in particular South Africa, are unique. Since the 1990’s South Africa has seen a considerable shift in the morphological and cultural make-up of the South African National Defence Force (SANDF). The result is a mix of soldiers from a variety of ethnic backgrounds. Ethnic differences may ultimately impact performance particularly as research has postulated that Blacks and Whites may differ in body composition and body proportions. It is highly probable then that the universal recommendations of optimal marching speeds, load masses and gradients need to be modified to accommodate the diversity of soldiers which currently comprise the SANDF.
- Full Text:
- Date Issued: 2001
- Authors: Christie, Candice J , Todd, Andrew I
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:6749 , http://hdl.handle.net/10962/d1009329
- Description: While extensive military research has been conducted in developed countries, very little work has been done on soldiers in industrially developing countries (IDCs). Although many aspects of marching are similar around the globe, the challenges facing soldiers in IDCs, and in particular South Africa, are unique. Since the 1990’s South Africa has seen a considerable shift in the morphological and cultural make-up of the South African National Defence Force (SANDF). The result is a mix of soldiers from a variety of ethnic backgrounds. Ethnic differences may ultimately impact performance particularly as research has postulated that Blacks and Whites may differ in body composition and body proportions. It is highly probable then that the universal recommendations of optimal marching speeds, load masses and gradients need to be modified to accommodate the diversity of soldiers which currently comprise the SANDF.
- Full Text:
- Date Issued: 2001
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