Thesis (MScEng)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: The purpose of this study was to investigate the specification and use of appropriate seating systems to reduce whole-body vibration exposure in typical vehicles used in South African industry. As part of this study six suspension seats, which the manufacturers claim satisfy the requirements in ISO 7096 (2000), were tested. Six test subjects, three light and three heavy as specified in ISO 7096, were used to estimate the seat transmissibility functions in the vertical direction of the six different suspension seats. Transmissibility functions were measured in the laboratory using two excitation levels, 1m/s2 and 2 m/s2 r.m.s., of broadband frequency vibration and a spectrum approximating the EM5 spectral class in ISO 7096. SEA T values were calculated for operational vibration data measured in an articulated dump truck and a three-wheeled logger. It was shown that SEAT values for the EM1 spectral class could not be reliably estimated from seat transmissibility functions and need to be measured directly in the time-domain. The measurement procedures and seat selection criteria developed in this research project were used to compile a set of "Design Guidelines for Seat Selection for Whole-Body Vibration Control in Industrial Vehicles". These guidelines will provide manufacturers with an easy-to-implement methodology to control whole-body vibration transmitted to the operators of industrial vehicles and to comply with international regulations for whole-body vibration transmission. / AFRIKAANSE OPSOMMING: Die doel van die studie was om die spesifikasies en gebruike van geskikte sitplek stelsels van uit Suid Afrikaanse industriële voertuie, wat heel-liggaam vibrasies verminder, te ondersoek. Ses suspensiesitplekke, wat deur die vervaardigers voorgeskryf word, is getoets om te sien of hulle aan die ISO 7096 (2000) vereistes voldoen. Ses persone, waarvan drie lig en drie swaar is, soos in ISO 7096 voorgeskryf, is gebruik om die sitplek oordragsfunksies in die vertikale rigting vir die ses verskillende suspensiesitplekke te skat. Die oordragsfunksies is in die laboratorium gemeet deur twee opwekkingsvlakke, 1m/s2 en 2m/s2 w.g.k., van wyeband frekwensie vibrasie en n spektrum beraam tot die EMS spektrum soos in ISO 7096. 'SEA T' waardes was vanaf operationele vibrasie data wat in ge-artikuleerde vragmotors en driewiel- 'loggers' gemeet is bereken. Daar is gewys dat betroubare 'SEAT waardes vir die EM1 spektrum nie van sitplek oordragsfunksies geskat kan word nie, maar dat dit eerder direk van die tyd-gebied afgelees moet word. Die metings prosedures en die sitplek keuse vereistes wat in die navorsingsprojek ontwikkel is, is gebruik om "Ontwerp Riglyne vir Sitplek Keuse Vereistes vir Heel- Liggaam Vibrasie in Industriële Voertuie" saam te stel. Hierdie riglyne sal vervaardigers met maklik toepasbare metodes toerus om heel-liggaam vibrasie, wat oorgedra word na industriële voertuig operateurs, te beheer en om aan internasionale regulasies t.o.v. heel-liggaam vibrasie oordrag te kan voldoen.

Thesis (MTech (Environmental Health))--Peninsula Technikon, Cape Town, 2004 / AIM &; OBJECTIVES: a) To quantify human vibration exposnres among the various similar occupational groups present on the mine, b) To determine the degree of vibration risk posed onto the mineworkers and c) To recommend and implement a sustainable human vibration management control progranune. METHODOLOGY: A cross-sectional descriptive study design was carried out on 135 mine workers employed in various similar occupational groups at Rossing Uranium mine, Namibia Data acquisition originated from a multi-stage proportionally stratified random sampling technique. An approved Human Vibration measuring instrument was utilized to measure Hand-arm and Wholebcdy vibration exposure levels [Aeq (m/s2 )] prevalent among the similar exposure groups. A structured questionnaire, developed specifically for the actual work environment enabled the collection of information such as work history, type of vibration exposure, exposure duration and vibration symptoms. Furthermore, group specific results [A(8)] were computed by means of the latest internationally accepted Health & Safety Executive Vibration calculators. In addition, statistical analyses were performed in order to establish the occupational groups that are at increased risk for the development of hand-arm and wholebody vibration induced health disorders.

Thesis (M.Tech.: Chiropractic)--Durban University of Technology, 2008 / Core strengthening has become a major trend in the rehabilitation of patients suffering with acute low back pain. Clinical trials have shown that core strengthening is beneficial for patients with low back pain. According to the literature, core strengthening consists of activating the trunk musculature in order to stabilize hypermobile symptomatic joints and thus, lessen mechanical stress to the spine. Literature suggests that vibration/acceleration training may be a more effective and sufficient method of core stability exercises, with regards to core muscle endurance and activation in treatment of acute low back pain. This may have more advantages than using traditional core stability exercises in the treatment of acute low back pain. However, vibration/acceleration training as core stability exercises has yet to be investigated. In order to choose the most appropriate treatment protocol for managing this condition, it is essential for research to be carried out to identify the most effective treatment, which would allow for better overall management of low back pain during the acute period. Therefore, this study was designed to establish the effectiveness of vibration/acceleration training as a core stability exercise in the treatment of acute low back pain and to establish whether this protocol should be utilized routinely in the management of this condition.

Whole body vibration (WBV) is a technique that has been shown to induce positive blood flow changes, however little is known about the effect of different vibration amplitudes on arterial blood flow. Purpose. The purpose of this study was to determine the effect of 2 different amplitudes during an acute bout of WBV on blood flow through the popliteal artery. Methods. Thirty healthy, recreationally active subjects (15 women, 15 men) aged 19-34 years performed two, 10 - minute bouts of vibration at a frequency of 30 Hz and high amplitude (6 mm) or low amplitude (3 mm) in random order after a period of prone rest. Doppler ultrasound was used to assess changes in blood flow. Mean blood flow velocity, peak velocity, end-diastolic velocity, pulsatility index, and resistive index measures were taken immediately before vibration and immediately after. Results. Mean blood flow velocity increased after 10 minutes of WBV. Mean velocity increased more in the 6mm trial (pre= 21.6 ± 4.74 cm/s, post= 25.3 ± 6.11 cm/s) than in the 3mm trial (pre= 22.3 ± 4.33 cm/s, post= 23.5 ± 5.94 cm/s). Peak blood flow velocity increased following 10 minutes of WBV and increased more in the 6mm trial (pre= 37.1 ± 9.78 cm/s, post= 43.7 ± 10.95 cm/s) than in the 3mm trial (pre= 37.8 ± 8.92 cm/s, post= 39.4 ± 10.5 cm/s) following 10 minutes of passive WBV. Pulsatility index also increased significantly following 10 minutes of WBV and increased more in the 6mm trial (pre= 1.639 ± 0.1299, post= 1.729 ± 0.1324) than in the 3mm trial (pre= 1.660 ± 0.1219, post= 1.671 ± 0.1428). No main effects or interactions were observed for resistive index or end diastolic blood flow velocity (P>0.05). Conclusion. Ten minutes of passive WBV increases blood flow velocity. High amplitude (6 mm) produced a more pronounced increase in blood flow than the low amplitude (3 mm). Given the relationship between blood flow velocity and WBV, these results suggest that amplitude plays a role in increasing blood flow and that high amplitude (6 mm) may be more effective than low amplitude (3 mm) in improving circulation to the lower leg. / School of Physical Education, Sport, and Exercise Science

Background: Whole-body vibration (WBV) has been proposed as a viable alternative, or adjuvant to exercise for power development in athletes. More recently individualized frequency (I-Freq) has been introduced with the notion that individuals may elicit a greater reflex response to different levels (Hz) of vibration. Purpose: The aim of the study was to evaluate acute WBV as a feasible intervention to increase power in trained cyclists. Additionally, to evaluate the efficacy of utilizing I-Freq as an alternative to 30Hz, a common frequency seen in the literature. Methods: Twelve highly-trained, competitive male cyclists (age= 29.9 yrs ± SD 10.0; body height=175.4 cm ± SD 7.8; body mass= 77.3 kg ± SD 13.9) free of musculoskeletal injury or pathology participated in the study. The Wingate test for anaerobic power was administered on three occasions following a control of no vibration, 30 Hz, and I-freq. Measures of peak power (PP), average power (AP) and rate of fatigue were recorded and compared to the vibratory conditions using separate RM-ANOVA’s. Results: PP, AP, and rate of fatigue were not significantly impacted by 30 Hz and I-Freq vibration interventions (p > 0.05). Conclusion: Acute WBV using the parameters of the present study may not have been practical to elicit an increase in power as potential changes in the highly trained population may have been muted as a function of training status. / School of Physical Education, Sport, and Exercise Science