Shoulder injuries affect athletes who participate in overhead sports, such as swimming, baseball or basketball. This is due to the high loading, large range of motion and repetitive nature of the sporting task. Impingement has been identified as the most common cause of shoulder pain in overhead athletes. Cricket bowling involves one of the more complex sporting tasks where the arm goes through a large range of motion during circumduction to project the cricket ball at varying degrees of speed and spin where injury surveillance research estimates that over 20% of cricket injuries are related to the upper limb with the glenohumeral joint being the second most injured site. Similar to other overhead athletes, cricket bowlers have a prevalence of shoulder injury and pain with loss of internal rotation. It is hypothesised that this is due to large distraction forces and muscle imbalance at the glenohumeral joint. A second, specific hypothesis is that bowlers who have greater internal rotation after delivering the cricket ball are more likely to suffer from impingement. The motivation for this study is derived from these hypotheses. The aim of this thesis was to test the hypotheses above and investigate potential shoulder injury risk in cricket bowlers. A full body 3D kinematic analysis of fast and slow bowling actions was conducted and a musculoskeletal model used to investigate joint forces and muscle activations at the shoulder. Technical advances were made in musculoskeletal modelling; these included a new kinematic optimisation routine and improvements in the muscle wrapping method. The performance of a scapula tracker in full speed bowling trials showed good repeatability. There was however, significantly greater posterior/anterior tilt and internal rotation underlining the effect of speed of movement on the scapula tracker that was used. At ball release, the glenohumeral adduction angle for fast bowlers was between 36° - 80° and 59° - 66° for slow bowlers with the humerus externally rotated within a range of 90° - 140° and 71° - 131° for both sets of bowlers respectively. The analysis showed that one potentially vulnerable position was in the region between upper arm horizontal and ball release due to the location of the joint reaction force and its magntiude. A large distraction force was reported for bowlers where the superior shear forces was also a key factor in determining the risk on injuries at the joint. Predicted activation pattern for subscapularis substantiate the risk of impingement injuries due to overuse and fatigue during rotation of the arm from upper arm horizontal to ball release. In addition, internal/external glenohumeral joint torque values were similar for both sets of bowlers with the peak value occuring midway between upper arm horizontal and ball release. Further work should concentrate on the link between technique and musculoskeletal loads and thus allow training to mitigate the risk of shoulder injury.

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The research presented in this thesis explores the potential uses of KGM and the development of KGM containing hydrogels for wound healing applications. The work involved characterization of five different species of Amorphophallus and investigating the biological activity of KGM and different molecular weight fractions of KGM on skin cells. KGM stimulated fibroblast (but not keratinocyte) proliferation and these effect were influenced by the species, Glc:Man ratio, % of glucomannan, molecular weight and the treatments of KGM. KGM also had the ability to maintain fibroblasts and ADMSC viabilities in unchanged medium for 20 days. The involvement of carbohydrate binding receptors on skin cells was also investigated to obtain a better understanding of the biological activity of KGM. KGM also had the potential for cell transportation where examination subjected to shear stress showed positive result. Following these, two sets of KGM hydrogels; crosslinked KGM and interpenetrating network (IPN); (semi IPN and graft-conetworks) were then developed and characterized using FTIR, DSC, SEM and 13C solid state NMR spectroscopy and their water content were examined. The crosslinked KGM was synthesized at various concentrations of KGM and Ce(IV), while the IPNs were made of KGM and poly(N-vinyl pyrrolidinone) (P(NVP)) crosslinked with poly(ethylene glycol diacrylate) (PEGDA) using photopolymerisation. Graft-conetwork hydrogels’ EWC of 85-90% was very stimulatory to fibroblast proliferation and the migration of both keratinocytes and fibroblasts while semi IPN with the highest EWC of (90-95%) and water content did not. Differences in the chemistry and water properties of the hydrogels had significant influences in their biological activities. Examination on 3D tissue engineered skin and wound models showed that the KGM containing hydrogels were able to decrease the extent of skin contracture without affecting the reepithelisation process. Taken together these data support a potential role for KGM and KGM containing hydrogels in wound healing.

Lower extremity non-contact injuries are common in male youth soccer players. Altered neuromuscular control defined as muscle strength, power or activation patterns that lead to increased joint loads has been suggested as a mechanism that underpins the occurrence of these injuries during rapid deceleration tasks. However, data pertaining to neuromuscular risk factors and screening in male youth soccer players is sparse. The purpose of this thesis was to investigate the validity of a novel movement screen to predict injury risk in elite male youth soccer players. Study 1 examined the test re-test reliability of a range of field-based neuromuscular control tests reporting acceptable values for measures of single leg dynamic balance, landing force, maximal hop distance and tuck jump knee kinematics; however, other commonly used assessments were more variable. The effects of chronological age on the measures deemed reliable in study 1 were then analysed in study 2. A number of between group differences were evident but this pattern was variable across the different constructs of neuromuscular control, thus an age-specific training emphasis may be required at different stages of a young player‟s development. Also, the normative data included for a range of chronological age groups in this study may be useful for practitioners, from which fluctuations in performances can be identified. The results of study 3 showed acceptable within subject variation on the majority of the tests measured at three time points across a soccer season. However, percentage change scores in neuromuscular control were more variable and differences between test sessions were often considerably lower than the random variation, thus observed changes may not be meaningful. However, single leg countermovement jump forces increased considerably throughout the season indicating that a „real‟ change occurred and this may be associated with greater injury risk. Seasonal variation in injury occurrence was also identified in study 4, but a major finding was a three-fold increase in player incidence rate since the introduction of an early soccer specialisation model in the United Kingdom. This indicates that elite male youth players are now at a greater risk of injury. The final study examined the ability of a novel movement screen to predict non-contact lower extremity injury risk in male youth soccer players. A combination of anthropometric and neuromuscular risk factors were shown as predictors, but there was variability across the different chronological age groups. Single leg countermovement jump landing force asymmetry was the most frequently reported risk factor and univariate analysis also identified a number of significant predictors in respective chronological age groups. The results of this study provide an evidenced-based diagnostic assessment tool from which “at risk” players could be identified; the injury prevention asymmetry soccer screen (i-PASS). However, greater weightings of specific assessments may be required at different stages of a child‟s development due to variability across age groups. This thesis has made an original and significant contribution to the existing paediatric injury risk screening literature for soccer players. Furthermore, these findings can easily be applied by practitioners to more accurately screen their players and develop targeted prevention strategies to reduce injury risk.

Vertebral fractures are a severe cause of morbidity and disability. In particular, burst fractures are a common traumatic injury presenting neurological impairment in 47 % of cases. However, diagnosis and planning of the treatment is challenging as the injury originates in highly dynamic conditions. Short-segment pedicle instrumentation (SSPI) in combination with kyphoplasty (SSPI–KP) has been used to provide additional stabilisation of the fracture. However, there is a lack of understanding about the effectiveness SSPI–KP. The aim of this study was to follow the fracture pathway, from onset to the outcome of surgical treatment. The first part focused on the phenomena underlying fracture creation and the dynamics of interpedicular widening (IPW). Although associated with neurological deficit, no previous study has shown how IPW evolves at fracture initiation. Subsequently the performance of treatment was assessed to evaluate how KP can improve SSPI to a simulated early follow-up. Burst fractures were induced in 12 human three-adjacent-vertebrae segments. Following fracture investigation, SSPI and SSPI–KP were performed, and samples underwent fatigue loading. Image processing of high-resolution CT scans was performed to assess anatomical changes at consecutive experimental stages on the treated and adjacent vertebrae. Experiments proved that IPW reaches a maximum at fracture onset and then decreases to the value measured clinically. SSPI–KP marginally improved stability of the treated spine, whilst providing a significant restoration of the endplate geometry. Vertebral body underwent significant changes in height and endplate curvature throughout the fracture pathway. This study provided further insight on the biomechanics of vertebral fractures and the findings can be used to improve and/or develop novel treatments as well as validate numerical models for retrospective assessment of the injury. In addition, outcomes from the collaboration work on the development of a computational simulation may help better understand cancer related vertebral fractures.

The management of fractures of the distal femur varies depending on the patient’s functional demands, fracture pattern, the availability of appropriate implants and the skill-set of the operating surgeon. It is widely accepted that the treatment of these fractures are challenging due to its prevalence amongst the elderly, a group with confounding co-morbidities, a high percentage of joint prosthesis and osteoporosis, which increase the technical demands on the surgeon and the selected implant. Locking osteosynthesis devices have been shown to provide superior stability to axial loading compared with traditional, unlocked osteosynthesis plate-screw constructs, blade plates and intra-medullary nails. However, the outcome following fixation with first-generation, fixed-angle, locking plates and the newer, poly-angled locking plates remains obscure. This prospective multi-centre prospective pilot study was undertaken to investigate this issue. Forty patients with distal femoral fractures were randomised into two locking osteosynthesis device groups, the fixed-angled, Less Invasive Stabilisation System (LISS) group and the multi-angled, POLYAX plate group, in a 1:1 ratio. Operative, functional and radiological outcomes including; operation time, length of hospital stay, radiological union rates, Oxford knee scores and Quality of life measures (EQ-5D) were investigated and analysed within a 12 month follow-up period. The results showed an overall mortality rate of 12.5%. The rate of fracture union was 72.5 % at 6 months and 77.5% there after, with 3 patients requiring secondary procedures for non-union. One patient in the LISS group and 1 patients in the Polyax group required revision surgery for implant failure. Statistically analysis of the data showed no significant differences in both primary (fracture union) and secondary outcomes between either plating system. Based on our findings, we conclude that patient factors and surgical technic carry more weight in determining the outcome of these injuries rather than the choice of locking osteosynthesis implant, be it mono or poly-angled.

Ongoing chronic back pain and chronic spinal injury prevalence in the gymnastics population is a major concern for the health and wellbeing of female gymnasts. To inform biomechanical screening approaches, the aim of the research is to develop understanding of the contribution of physical development to biomechanical indicators of chronic spinal injury risk in female artistic gymnasts. Chronological ageing, maturation and growth of competitive female artistic gymnasts between the ages of nine and 15 years were evaluated at three time points across a 12 month period. CODA motion analysis and Kistler force plate data informed the quantification of biomechanical risk indicators. Posture, general stability, centre of pressure range and lumbo-pelvic stability were determined through the performance of handstand and forward walkover skills and informed the respective risk indicators. Calculated through an image-based approach, anthropometric growth was established to have the greatest influence on biomechanical risk indicators of the physical development mechanisms. Within the gymnastics cohort, two forms of proportional growth were evidenced. Longitudinal empirical data revealed gymnasts with increased bicristal breadth growth in relation to biacromial breadth to have significantly greater biomechanical risk for posture and lumbo-pelvic stability in the handstand (p<0.05). Gymnasts who had increased growth rates of biacromial breadth in relation to bicristal breadth had significantly greater biomechanical risk for general stability in the handstand and forward walkover skills (p<0.05). Novel empirical quantification for the large influences of physical development mechanisms on biomechanical risk (maximum r2 = 0.82) underpinned the importance of proportional growth consideration in injury screening practice. Evaluation of the transverse torso moment of inertia at a discrete time point provided preliminary support for cross-sectional use of the inertial measure to forecast longitudinal growth trends. Identification of prominent biomechanical risk indicators for individual gymnasts using discrete data may provide direction of injury prevention focus for practitioners.

Physical performance tests (PPTs) have great allure to sports medicine professionals, coaches, and athletes because they are inexpensive, easy to perform in a variety of settings, and reportedly can be used as outcome measures to determine patient progress and readiness for return to sport as well as prognostic variables to predict injury or performance. However, there has been no evidence-based summary of literature with regard to the clinical utility of physical performance tests in athletes and most studies examining the clinical utility of PPTs are of small sample size or performed in limited populations. In addition, there are very few prospective studies examining the predictive ability of PPTs in athletes with lower extremity injuries. This dissertation encompasses 2 systematic reviews highlighting the absolute dearth of evidence in existence, the introduction of some novel PPTs and the establishment of their reliability, and a large, pragmatic, prospective study examining the ability of PPTs to predict lower extremity injury in collegiate athletes. The most notable findings of the prospective study are first, that PPTs fall cleanly into 5 constructs: stability, active motion, motor control, power, and flexibility. Next, the constructs of hip stability and active motion predicted injury. Third, the construct of motor control predicted overuse injury. Finally, the constructs of hip stability, active motion, and motor control appear to modify the relationship between injury and prior injury. Finally, the constructs represented by PPTs seem to be more powerful predictors of injury than the previously established predictors of age, body mass index, gender, and excessive flexibility when examined in a multivariate model.

No description available.

No description available.