Musculotendinous stiffness and muscle function

Includes bibliographical references.Musculotendinous stiffness or elasticity is difficult to measure in vivo. Therefore, various procedures have been used in an attempt to quantify the contribution of the elastic properties of muscle and tendon to stretch shortening cycle performance. The results are variable, perhaps as a result of the different techniques utilised. Although several studies have suggested an association between a more compliant muscle-tendon complex, and enhanced stretch shortening cycle performance, this interpretation is not conclusive and needs further testing with particular attention being focused on the non-invasive, in vivo measurement of musculotendinous stiffness. Accordingly, the primary goal of this dissertation was to identify the relationship between the mechanical characteristics of the muscle-tendon complex, in particular tendon stiffness, and stretch shortening cycle muscle function

Geology, structure and mineralization of the Onguati area, Karibib district, central Namibia

The study area is situated in the Southern Central Zone of the intracontinental Pan-African Damara Orogen, approximately 20km NNE of Navachab Gold Mine in the Karibib district of Namibia. Mesothermal vein systems with Cu-Fe±Au mineralization are hosted by amphibolite facies calcitic and dolomitic marbles belonging to the Navachab Member of the Karibib Formation, and are best developed around the defunct Onguati Copper Mine, Brown Mountain and Western Workings areas. The Onguati study area is located in the saddle region of a moderately-to-gently inclined anticlinorium that experienced significant flattening during NNW-SSE-directed compression. The parallelogram arrangement of ENE- and NNE-trending thrusts and reverse faults that surround the Onguati study area may have developed when the direction of greatest principle subregional stress was oriented WSW-ESE. These structures define part of a Riedel shear system and later faults may have developed in the position of R and P shears respectively. Significant strain partitioning occurred between the ductile calcitic marbles which host the best developed, shear-related vein systems and the more competent dolomitic marbles. The thickness distributions of veins in the marbles of the Onguati Mine, Brown Mountain and Western Workings areas conform to a fractal or power-law distribution, The most intensely mineralized vein systems in the Onguati Mine and Western Workings calcitic marbles share similar low fractal dimensions (D-values) of 0.41 and 0.37 respectively. Veins In the calcitic and dolomitic marbles of the Brown Mountain area and in the dolomitic marbles of Western Workings have elevated D-values (>0.60) and are poorly mineralized. The low D-values «0.40) of the well mineralized vein systems reflect the higher degree of fracture connectivity. These vein systems were capable of efficiently draining and localizing large volumes of mineralizing fluids from crustal-scale structures. A metamorphic devolatization model is proposed where the entire Damaran metasedimentary and meta-volcanic package is seen as a large source area of very low concentrations of Cu, Au and other metals. Localization of deformation into crustal-scale faults and shear zones led to regional-scale hydrothermal fluid flow and focussing into the upstream fracture networks of the Onguati study area. Strong mineralization resulted when fluids encountered the reactive marble lithologie

SA Rugby Injury and Illness Surveillance and Prevention Project (SARIISPP): The Currie Cup Injury Surveillance Report 2022

The content of the report is based on data collected by the SA Rugby Injury and Illness Surveillance and Prevention Project (SARIISPP) steering group

The Currie Cup Premiership Competition Injury Surveillance Report 2019

The content of the report is based on data collected by the SA Rugby Injury and Illness Surveillance and Prevention Project (SARIISPP) steering group

SARU Youth Week Injury Surveillance Report 2019

The content of the report is based on data collected by the SA Rugby Injury and Illness Surveillance and Prevention Project (SARIISPP) steering group

SA Rugby Injury and Illness Surveillance and Prevention Project (SARIISPP): The Carling Currie Cup Premiership Competition Injury Surveillance Report 2021

The content of the report is based on data collected by the SA Rugby Injury and Illness Surveillance and Prevention Project (SARIISPP) steering group

BokSmart - implementing a National Rugby Safety Programme

The BokSmart National Rugby Safety Programme is a joint initiative between the South African Rugby Union and the Chris Burger/Petro Jackson Players Fund aimed at implementing evidencebased sports medicine and exercise research to prevent injury and enhance performance at all levels of rugby union in South Africa. The BokSmart programme has four main elements: Ø the BokSmart Rugby Safety Workshops, a compulsory DVD-facilitated course that all coaches and referees in SA attend on a biennial basis, Ø the BokSmart Rugby Medic Programme, an entry-level rugby first aid short course aimed at training members of underprivileged rugby-playing communities, Ø the toll-free BokSmart Spineline number, which assists in the management and road transport of head-, neck- and spine-injured rugby players to the nearest appropriate medical facility, and Ø the freely accessible online educational resource www.boksmart.com, which provides researched documentation and practical advice on a variety of rugby-related topics.http://bjsm.bmj.com/hb201

ASSESSING THE KINEMATICS OF A NOVEL COLLISION SPORT SIMULATOR

The tackle is a common and dynamic phase of play in rugby union and other collision sports. It is necessary to study the tackle to characterise its various facets that include impact force, biological markers, and technical and skill-related requirements. Therefore, a novel collision sport simulator was &signed to replicate front-on tackle situations. This study describes the movement and velocity properties of the simulator relative to the force of pressure exerted by a pneumatic system. Future research using this simulator may guide the development of skill training/conditioning sessions and injury prevention programs

Training volume and injury incidence in a professional rugby union team

Objective. To describe the incidence of injuries in a professional rugby team, and to identify any associations between injury rates and training volume. Methods. This retrospective, descriptive study included all injuries diagnosed as grade 1 and above in a South African Super 12 rugby team. Injury incidence and injury rates were calculated and compared with training volume and hours of match play. Results. Thirty-eight male rugby players were injured during the study period. The total number of annual injuries decreased from 50 (2002) to 38 (2004) (χ2=0.84, p=0.36). The number of new injuries showed a similar trend (χ2=2.81, p=0.09), while the number of recurring injuries increased over the 3-year period. There was a tendency for total in-season injury rates to decrease over the 3 years (χ2=2.89, p=0.09). The pre-season injury rate increased significantly over the 3 years (χ2=12.7, p<0.01), coupled with a reduction in training exposure over the pre-season phase. Conclusions. One has to be cognisant of the balance between performance improvement and injury risk when designing training programmes for elite rugby players. Although the reduction in training volume was associated with a slight reduction in the number of acute injuries and in-season injury rates over the three seasons, the performance of the team changed from 3rd to 7th (2002 and 2004, respectively). Further studies are required to determine the optimal training necessary to improve rugby performance while reducing injury rates

Legal and illegal ruck cleanouts in South African non-professional youth rugby

CITATION: Kruger, S. et al. 2022. Legal and illegal ruck cleanouts in South African non-professional youth rugby. International Journal of Sports Science & Coaching, 1-9. doi:10.1177/17479541221122439.The original publication is available at https://journals.sagepub.com/home/spoThe ruck area is responsible for the second-highest number of rugby union injuries, therefor it is necessary to investigate and understand the ruck better for improved player safety. The study aimed to investigate and compare incidents of legal and illegal ruck cleanouts in non-professional youth rugby. Using Nacpsort Scout Plus software, 118 South African Rugby Union under 18 Youth Week tournament matches were coded between 2015 and 2019. In total, 35 545 ruck cleanouts were coded, of which 32 641 (91.8%) were legal and 2 904 (8.2%) were illegal. Of the 2 904 illegal cleanouts, 2 676 (92.2%) were deemed ‘not dangerous’ and 228 (7.8%) were considered ‘dangerous’. The ‘dangerous’ ruck cleanouts represented 0.6% of the total ruck cleanouts. Of the most common illegal ruck cleanouts, “not supporting own body weight” were mostly ‘not dangerous’ (2 498; 99.4%, p=0.01); and all “neck rolls” were considered ‘dangerous’ (147; 100.0%, p=0.02). The findings of the study suggest player behaviour can still be improved, with regular participation in regular safe and effective technique training drills. The risk of injury during the ruck can further be influenced positively by coaches, through regular coaching and training of safe and effective ruck techniques.https://journals.sagepub.com/doi/full/10.1177/17479541221122439Post-print versio