A dissertation submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Master of Science in Physiotherapy. Johannesburg, 2014 / Cycling has grown in popularity as a sport and is rated as one of the top 15 most popular sports in South Africa with more than 420 000 participants. Cyclists spend long continuous hours on the bicycle in an awkward position, which leads to unique overuse injuries. Overuse injuries in cyclists have been estimated to be as high as 85% with lower back and pelvis pain (LBPP) among the most common. The lower back and pelvis is the foundation the cyclist use for powering and controlling the bicycle and optimal functioning thereof is essential for optimal comfort and performance in cycling. The prolonged forward flexed position of the cyclist on the bicycle is regarded as one of the main contributors to LBPP in cyclists. Cyclists with LBPP are known to assume a position of greater lumbar flexion compared to those without but the reason for this has not been extensively explored. The purpose of this study was therefore to not only establish the prevalence of LBPP in cyclists in South Africa, but also identify factors associated with it in cyclists. The factors were considered in three broad categories: (1) training methods used, (2) intrinsic functioning of the cyclist and (3) bicycle set-up. Intrinsic and bicycle set-up factors included were those proposed to influence the forward-backward and side-to-side position of the cyclist on the bicycle and thereby lead to the development of LBPP in cyclists. The study had a cross-sectional descriptive design and comprised of two parts: a questionnaire (survey) investigating the prevalence of LBPP in cyclists together with the training methods used, and a physical assessment of the factors proposed to be associated with LBPP in cyclists. All cyclists belonging to cycling clubs registered with Cycling South Africa were invited to complete the online survey. From there, cyclists could indicate willingness to undergo a physical assessment which was done in the greater Gauteng area. The physical assessment included the following measurements: the lumbar curvature on the bicycle in all three handlebar positions, strength of gluteus maximus and gluteus medius, extensibility of the hamstring muscle group, control of lumbar movement in the direction of flexion, neurodynamics, active straight leg raise for load transfer, one leg stance test for lateral shift of the pelvis, leg-length discrepancy and bicycle set-up (saddle height, set-back and angle, handlebar height, forward reach, cleat position). The study revealed a lifetime prevalence of 65% for LBPP among cyclists in South Africa. Of the factors assessed, only the lumbar curvature in the brake lever position i.e. flexion of the lumbar spine (p=0.03) and the weakness of gluteus medius (Gmed) (p=0.05) were significantly related to LBPP in cyclists. This study was the first to assess the relationship between so many different factors and LBPP in cyclists, and the largest of its kind in cycling. Understanding the relationship between these factors and LBPP in cyclists can guide the development of preventative strategies and interventions with the aim of reducing the occurrence and recurrence of LBPP in cyclists and limiting the impact thereof.

Yip Yin Bing. / "July 1999." / Thesis (Ph.D.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (p. 163-177). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese. / Yip Yin Bing.

by Wan Yu Kwan. / Thesis submitted in: December 1999. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 112-125). / Abstracts in English and Chinese. / Acknowledgement --- p.2 / Abstract --- p.3 / Table of Contents --- p.5 / Chapter Chapter 1 - --- Introduction --- p.7 / Chapter 1.1 --- Contribution of lifting techniques on risk assessment and training on manual materials handling --- p.7 / Chapter 1.2 --- Objectives --- p.12 / Chapter 1.3 --- Hypotheses --- p.12 / Chapter 1.4 --- Significance of Study --- p.13 / Chapter Chapter 2 - --- Literature Review --- p.14 / Chapter 2.1 --- Societal concerns on employee compensation --- p.14 / Chapter 2.2 --- Etiology of low back injury --- p.15 / Chapter 2.2.1 --- Compression forces on vertebral joints --- p.16 / Chapter 2.2.2 --- Shear forces on vertebral joints --- p.17 / Chapter 2.3 --- Lifting techniques --- p.18 / Chapter 2.3.1 --- Effect of lifting techniques on curvature of the spine --- p.22 / Chapter 2.3.2 --- Importance of leg muscles in manual lifting --- p.22 / Chapter 2.4 --- Prediction of low back injury in manual lifting --- p.24 / Chapter 2.4.1 --- Compression forces and moments --- p.26 / Chapter 2.4.2 --- Balance control --- p.29 / Chapter 2.4.3 --- Application of Surface electromyography in ergonomics --- p.31 / Chapter Chapter 3 - --- Method --- p.34 / Chapter 3.1 --- Subject recruitment --- p.34 / Chapter 3.2 --- Equipment --- p.35 / Chapter 3.2.1 --- Force platform --- p.35 / Chapter 3.2.2 --- Motion analysis system --- p.37 / Chapter 3.2.3 --- Surface electromyography --- p.38 / Chapter 3.3 --- Maximum voluntary contraction test --- p.40 / Chapter 3.3.1 --- MVC of vastus medialis --- p.41 / Chapter 3.3.2 --- MVC of medial gastrocnemius --- p.42 / Chapter 3.3.3 --- MVC of erector spinae --- p.43 / Chapter 3.4 --- Lifting techniques --- p.44 / Chapter 3.5 --- Experimental procedures --- p.48 / Chapter 3.6 --- Statistical analysis --- p.53 / Chapter Chapter 4 - --- Results and Dicussion --- p.54 / Chapter 4.1 --- No. of cases in the study --- p.54 / Chapter 4.2 --- Phases of lifting --- p.55 / Chapter 4.3 --- Process time --- p.56 / Chapter 4.4 --- Trunk inclination angles --- p.62 / Chapter 4.5 --- Hip joint angles --- p.67 / Chapter 4.6 --- Knee joint angles --- p.73 / Chapter 4.7 --- Center of mass of box --- p.79 / Chapter 4.8 --- Muscle activities --- p.84 / Chapter Chapter 5 - --- Conclusion --- p.109 / Chapter Chapter 6 - --- References --- p.112