Thesis (MScPhysio)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Aim: The aim of the study was to improve understanding of the hip joint kinematics in cricket fast bowlers and to ascertain whether a relationship exists between hip joint biomechanical parameters, including kinematics, ROM characteristics and lumbar symptoms. Study design: A descriptive cross-sectional study was conducted. Participants: Sixteen adult male fast bowlers between the ages of 18 and 40 years old, playing first-club league, were featured in the study. Main outcome measures: To obtain data with regards to the training history, as well as the nature of lumbar-spine symptoms experienced by the cricket fast bowlers, a newly designed questionnaire was compiled. For analysis of the front foot hip joint ROM and kinematics, the biomechanical equipment used included: a two-dimensional Canon MV950 Digital Video Camcorder, a Kodak EasyShare C310 camera and XSENS Motion Tracking equipment (Xsens Technologies B. V., Enschede, Netherlands). Results: Eight of the sixteen bowlers in our study experienced LBP in the season with seven of these bowlers presenting with recent symptoms most of which are experienced after bowling a spell and described as “tightness” or a “stabbing pain” in the lower back. Intensity of LBP ranged between 1/10 to 8/10. Front foot hip joint kinematics of fast bowlers showed highly individualised patterns of movement between different subjects. Medium amplitude movements in the flexion/extension as well as the rotation plane of movement showed a significant difference in bowlers with- and without LBP. No significant differences between groups with LBP and without LBP were found in the three passive hip ROM measurements. Conclusions: It has proved to be very difficult to improve the understanding of the front foot hip biomechanics in cricket fast bowlers due to the high inter-subject variability. Variability in movement patterns remains under-researched by sports biomechanics. Although decreased hip mobility could alter mechanical forces transmitted to the lumbar spine and therefore predispose or be a causative factor in LBP development, this study found no significant relation between these parameters. The sample size was very small in this study which will influence the validity of results. Our study confirmed the high incidence of LBP and preventative efforts for bowlers should therefore be strongly supported. / AFRIKAANSE OPSOMMING: Doelwit: Die doelwit van die studie was om die heupgewrig kinematika van krieket snelboulers beter te verstaan en om vas te stel of daar ‘n verwantskap bestaan tussen heupgewrig biomeganiese parameters, insluitende kinematika, omvang van beweging karakter en lumbale simptome. Studie ontwerp: ‘n Deursneë beskrywende studie is onderneem. Deelnemers: Sestien volwasse manlike snelboulers tussen die ouderdomme van 18 en 40 jaar oud wat eerste liga speel maak deel uit van die studie. Hoof uitkoms maatreëls: ‘n Nuut ontwerpte vraelys is opgestel om data aangaande oefen geskiedenis sowel as aard van lumbale simptome wat deur krieket snelboulers ervaar word in te samel. Die biomeganiese apparaat wat gebruik is vir die analiese van die voorvoet heup omvang van beweging, sowel as die kinematika, sluit in: ‘n twee dimensionele Canon MV950 Digitale Video Camcorder, ‘n Kodak EasyShare C310 kamera en XSENS beweging volgende apparaat (Xsens Technologies B. V., Enschede, Netherlands). Resultate: Agt van die sestien boulers in ons studie het lae rug pyn in die seisoen ervaar. Sewe van die boulers het gepresenteer met onlangse simptome waarvan die meeste na ‘n bouler se boulbeurt ervaar is en beskryf was as ‘n “styfheid” of “steekpyn” in die lae rug. Die intensiteit van die lae rug pyn het gewissel tussen 1/10 en 8/10. Voorvoet heup kinematika van snelboulers het hoogs individualistiese patrone van beweging getoon tussen verskillende deelnemers. Medium amplitude bewegings in die fleksie/ekstensie sowel as die rotasie plein van beweging het ‘n beduidende verskil tussen boulers met- en sonder lae rug pyn getoon. Geen beduidende verskille tussen die groep met- en sonder rugpyn is gevind met die drie passiewe heup omvang van beweging meetings nie. Gevolgtrekkings: Dit blyk baie moelik te wees om die voorvoet heup biomeganika in krieket snelboulers beter te verstaan a.g.v. die hoë inter-deelnemer veranderlikheid. Veranderlikheid in bewegings patrone is nog nie genoeg nagevors deur sport biomeganici nie. Alhoewel ingekorte heup mobiliteit meganiese kragte wat deur die lumbale werwelkolom gaan kan wysig, en sodoende die ontwikkeling van lae rug pyn kan predisponeer of ‘n oorsakende faktor kan wees, het hierdie studie nie ‘n beduidende verwantskap tussen die parameters gevind nie. Die steekproef groote was baie klein en dit sal die geldigheid van die resultate beïnvloed. Ons studie het die hoë insidensie van lae rug pyn bevestig en pogings tot voorkomende maatreëls moet daarom ten sterkste ondersteun word.