Investigating playing-related musculoskeletal disorders in South African instrumental musicians
- Authors: Green, Erryn Mae
- Date: 2024-04-04
- Subjects: Musculoskeletal disorder , Musculoskeletal system Diseases , Musicians Wounds and injuries , Musicians Health and hygiene , Human engineering South Africa , Musicians Health risk assessment , Biomechanics , Musical instruments , Music genre
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/435310 , vital:73146
- Description: This study, one of the first studies in SA to investigate PRMD in a wideranging sample of instrumental musicians using a validated self-report tool, shows that PRMDs are highly prevalent among a range of SA musicians and have a considerably negative effect on musicians’ performance ability and quality of life. However, making inferences about most affected genre or instrumental group was challenging due to the small sample sizes in some categories. The results from this study confirm that the nature of PRMD development is indeed multi-factorial, with factors numerous individual and playing-related factors playing a role in the development of PRMDs in SA musicians. Better support and education on health promotion for musicians, including awareness of and prevention strategies for PRMDs in the SA context are needed which may reduce the prevalence of PRMDs. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2024
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- Date Issued: 2024-04-04
An investigation into the force-EMG relationship for static and dynamic exertions
- Authors: Koekemoer, Wesley Agosthinho
- Date: 2022-04-06
- Subjects: Electromyography , Force and energy , Muscles Physiology , Biomechanics , Muscle contraction , Isometric exercise , Isotonic exercise , Static and dynamic exertions
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291076 , vital:56816
- Description: The force-EMG relationship has multiple applications in varying fields of study and practice. One such application is the development of safety guidelines and regulations. Current guidelines are based on static muscle actions even though the majority of tasks encountered in industry are dynamic in nature. This may have negative implications for the health, safety, and productivity of workers as regulations based on static muscle actions may place higher force demands on manual labourers compared to what would be expected if regulations were based on dynamic muscle actions. Regulations based on dynamic muscle actions may be more effective in worker safety as the nature of the regulation matches that of the demand. Few studies have investigated the force-EMG relationship during dynamic muscle actions and the few that do exist have reported contradictory / mixed results. Therefore, the purpose of this study was to: 1) gain an understanding of EMG responses at different load levels, and 2) show how the relationship differs between static and dynamic muscle actions. A two-factorial repeated-measures experiment was developed for this study. Eighteen experimental conditions, utilizing six load levels (0%, 20%, 40%, 60%, 80%, and 100% of maximum voluntary force) for each of the three muscle actions (isometric, concentric and eccentric). Surface EMG responses were obtained under these conditions by repeatedly dorsiflexing and plantarflexing the foot, thus activating the soleus muscle. A maximum voluntary exertion on an isokinetic dynamometer determined the maximum force level, based on which the sub-maximal loads were calculated and added to a pulley system. 31 student participants were recruited for this experiment which was conducted over two sessions – one information and habituation session, and one experimental session. The EMG data recorded were processed and checked for normality and outliers. The data was then analysed via a General Linear Model analysis to determine the effect of exertion type and of load level on the muscle activity. Significant differences were identified at p<0.05 and followed by a Tukey post-hoc test. Correlation analyses were also conducted to determine the relationship between the force and EMG at all three exertion types. All dependent measures showed that as the load level increased so did the sEMG amplitude for all muscle actions. Muscle actions differed significantly between majority of six force levels. Correlations between the load levels and sEMG amplitude for each muscle action indicated a significant correlation with a moderate strength. The conclusion draws from this study that there is a positive correlation between force and sEMG amplitude, at all load levels, with a moderate strength. However, the muscle actions differed significantly from each other. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
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- Date Issued: 2022-04-06
Potential running related injury contributors in South African long-distance runners
- Authors: Jäger, Chloë Rose Laubscher
- Date: 2022-04-06
- Subjects: Running injuries South Africa , Long-distance running South Africa , Running Physiological aspects , Running shoes , Biomechanics , Chi-square test , Fisher exact test
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/290943 , vital:56801
- Description: Running related injuries (RRIs) are a common problem among long-distance runners, with injury rates ranging from 19.4% to 79.3%. Many studies have been done, investigating possible contributors to RRIs however, very few studies have investigated RRIs in South African long-distance runners, a population which may differ from previously studied populations. The current study aimed to build a descriptive profile of South African long-distance runners, as well as to determine associated factors that may contribute to RRIs. In order to do this, a cross-sectional, retrospective study design was employed using a questionnaire which was mostly electronically distributed. The sample consisted of 378 long-distance runners from each province in South Africa (SA). Using the Chi-square analysis and Fisher exact tests, significant associations were established (p<0.05). The current study found that certain RRI variables were associated with specific aspects of the participants’ personal characteristics and demographics, training characteristics, running experience, footwear, and cross training activities. Footwear and training characteristics produced the largest number of significant RRI associations. The findings of the current study could assist future research on RRIs in South African long-distance runners, by informing researchers of potential areas where more in-depth research is needed. In the long term, researchers may be able to narrow down the main contributors to RRI, possibly decreasing RRI rates in the unique population of South African long-distance runners. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
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- Date Issued: 2022-04-06
Improvements and optimization for a functional low-cost prosthetic hand
- Authors: Setty, Kiran
- Date: 2019
- Subjects: Biomechanics , Artificial limbs -- Design , Prosthesis -- Design
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/43655 , vital:36955
- Description: The following study investigates the work of the Touch Hand 4, which involves the development of a lowcost myoelectric prosthetic terminal hand device for transradial amputees. The Touch Hand 4 is an iteration of the Touch Hand project which attempts to make a functional, low-cost prosthetic hand which is capable of being accessible to more people relative to conventional myoelectric prosthetic hands as well as being used as a robotic UAV gripper. This research is motivated due to the lack of affordable myoelectric prosthetic hands in the global market. It is believed, with the current technology, it is capable of developing a prosthetic hand which can meet these needs. Research was performed through reviewing other prosthetic hands to understand the requirements for a prosthetic hand as well as understanding the market of prosthetic hands. Prosthetists were interviewed to obtain a perspective from medial professionals regarding the requirements for a prosthetic hand. Hand kinesiology was performed to understand the biomechanics of the human hand, which was emulated in the design of the Touch Hand 4. The mechanical design begun with developing and testing a concept design, which was used to design the general shape of the Touch Hand 4. SLS was chosen to print the prosthetic hand with. After performing a kinematics and static force simulation, the mechanical system was designed accordingly. Further research on EMG sensors was then performed to understand the requirements of using EMG signals to control a prosthetic hand. The electronics and control system were then designed according to the requirements of the prosthetic hand. Tests were performed, however, tests performed with an amputee using the device was affected to improper placement of the EMG sensors, leading to poor results. Tests performed without an amputee, however, showed that the prosthetic hand is capable of gripping various objects of different shapes and sizes. An investigation was also performed on the contributions the Touch Hand 4 could make as a UAV gripper, which showed that the Touch Hand 4 is more adaptable and versatile than any other UAV gripper available on the market.
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- Date Issued: 2019
The effect of load and technique on biomechanical and perceptual responses during dynamic pushing and pulling
- Authors: Desai, Sheena Dhiksha
- Date: 2009
- Subjects: Work -- Physiological aspects , Biomechanics , Human engineering , Lifting and carrying
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5109 , http://hdl.handle.net/10962/d1005187 , Work -- Physiological aspects , Biomechanics , Human engineering , Lifting and carrying
- Description: Changes in the industrial job profile, from lifting and lowering to repetitive dynamic pushing and pulling have been facilitated through the use of manual vehicles, aimed at minimising the workload. Yet, the demands of pushing and pulling have not been well documented. Using measures of the horizontal component of the hand forces, spinal kinematics, muscle activity at various sites on the upper body and body discomfort ratings, this study aimed at quantifying the biomechanical and perceptual demands of various dynamic push/pull techniques. 36 healthy male participants performed two-handed forward pushing, two-handed backward pulling and one-handed forward pulling, employing an industrial pallet jack supporting two loads of 250kg or 500kg. While no single technique was definitively identified as preferable regarding hand forces, pushing at 500kg elicited higher initial and sustained forces (p<0.05) than one- and two-handed pulling respectively. Increments in load mass from 250kg to 500kg resulted in significant differences in the initial, sustained and ending forces. With regard to spinal kinematics in the sagittal plane, two-handed pulling elicited the highest trunk flexion, and may therefore expose individuals to prolonged forward bending. Generally this technique was found to evoke the highest sagittal responses. Spinal kinematic measures in the lateral and transverse planes suggested that one-handed pulling was accompanied by the highest measures, and hence the greatest risk of developing lower back disorders related to this plane. Although various combinations of muscles were active during each technique, one-handed pulling and pushing, most often induced the highest muscle activation levels and two-handed pulling, the lowest. While erector spinae evidenced no significant differences between techniques at each load or between loads for the same technique, activation levels were high under all conditions. Perceptual ratings of body discomfort revealed that not only is the upper body susceptible to injuries during pushing and pulling, but also that the lower extremities may have a considerable role to play in these tasks, with the calves being a particular area of concern. Findings concluded that symmetrical pushing and pulling tasks are preferable.
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- Date Issued: 2009
The impact of load and frequency on the biomechanical, physiological and perceptual responses to dynamic pushing
- Authors: Cripwell, Adam Michael
- Date: 2007
- Subjects: Work -- Physiological aspects , Psychophysiology , Human engineering , Biomechanics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5144 , http://hdl.handle.net/10962/d1008183 , Work -- Physiological aspects , Psychophysiology , Human engineering , Biomechanics
- Description: The objective of the present research was to establish the biomechanical, physiological and perceptual responses of male operators to dynamic pushing tasks. The pushing tasks were performed using an industrial pallet jack with varying load/frequency combinations, in a controlled laboratory environment. Thirty healthy male subjects comprised the sample. Experimental procedures were conducted utilising the Chatillon ™ Dynamometer to measure force output in the initial, sustained and ending phases. The K4b2 Ergospirometer was used to assess physiological responses (heart rate and oxygen consumption [V02])' Nine recorded forces and nine experimental conditions formed the basis of this study, with subjects required to push three loads (200kg, 350kg, 500kg) at three frequencies (1120 sec, 1/40 sec, 1/60 sec) at a speed of 3.6km.h-1 over 14 metres on a co-efficient of friction controlled walkway for six minutes. Gait analysis, along with perceptions of exertion (,Central ' and 'Local' RPE) were collected during the third and sixth minutes of each condition . Body discomfort and contribution were identified upon completion of each condition. The results demonstrated that load and frequency interacted to influence responses within each domain. Increasing loads required increased force output during each stage of the push, which had a concomitant effect on physiological and perceptual responses. Significant differences arose between the initial, sustained and ending forces for each load, showing the direct relationship between load and force exertion. The combination of heaviest load/quickest frequency required the greatest physiological output, exceeding recommended guidelines for heart rate, V02 and energy expenditure responses. Intermediate combinations required moderate and acceptable energy cost. Linear relationships were established between heart rate and oxygen consumption , as well as between load and V02 , thus providing industrial practitioners an opportunity to evaluate task demands in situ. The combination of high forces and elevated physiological responses increased the subjective rating of the condition. The results emphasise the need to holistically consider all contributing factors in a dynamic pushing task. Dynamic pushing tasks place biomechanical, physiological and perceptual demands on the human operator, which must be minimised in order to ensure that this form of manual materials handling becomes sustainable in the long term.
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- Date Issued: 2007