Clinical methods to quantify trunk mobility in an elite male surfing population

Background: Thoracic mobility in the sagittal and horizontal planes are key requirements in the sport of surfing; however to date the normal values of these movements have not yet been quantified in a surfing population. Objectives: To develop a reliable method to quantify thoracic mobility in the sagittal plane; to assess the reliability of an existing thoracic rotation method, and quantify thoracic mobility in an elite male surfing population. Design: Clinical Measurement, reliability and comparative study. Methods: A total of 30 subjects were used to determine the reliability component. 15 elite surfers were used as part of a comparative analysis with age and gender matched controls. Results: Intraclass correlation coefficient values ranged between 0.95-0.99 (95% CI; 0.89-0.99) for both thoracic methods. The elite surfing group had significantly (p ≤ 0.05) greater rotation than the comparative group (mean rotation 63.57° versus 40.80°, respectively). Conclusion: This study has illustrated reliable methods to assess the thoracic spine in the sagittal plane and thoracic rotation. It has also quantified ROM in a surfing cohort; identifying thoracic rotation as a key movement. This information may provide clinicians, coaches and athletic trainers with imperative information regarding the importance of maintaining adequate thoracic rotation. © 2015 Elsevier Ltd

Retrospective analysis of chronic injuries in recreational and competitive surfers:Injury location, type, and mechanism

Only two studies have reported on chronic musculoskeletal surfing injuries. They found over half of the injuries were non-musculoskeletal, but did not consider mechanisms of injury. This study identified the location, type, and mechanisms of chronic injury in Australian recreational and competitive surfers using a crosssectional retrospective observational design. A total of 1,348 participants (91.3% males, 43.1% competitive surfers) reported 1,068 chronic injuries, 883 of which were classified as major. Lower back (23.2%), shoulder (22.4%), and knee (12.1%) regions had the most chronic injuries. Competitive surfers had significantly (p \u3c .05) more lower back, ankle/foot, and head/face injuries than recreational surfers. Injuries were mostly musculoskeletal with only 7.8% being of non-musculoskeletal origin. Prolonged paddling was the highest frequency (21.1%) for mechanism of injury followed by turning maneuvers (14.8%). The study results contribute to the limited research on chronic surfing injuries

Relationships between lower-body muscle structure and, lower-body strength, explosiveness and eccentric leg stiffness in adolescent athletes

The purpose of the present study was to determine whether any relationships were present between lower-body muscle structure and, lower-body strength, variables measured during a counter-movement jump (CMJ) and squat jump (SJ), and eccentric leg stiffness, in adolescent athletes. Thirty junior male (n = 23) and female (n = 7) surfing athletes (14.8 ± 1.7 y; 1.63 ± 0.09 m; 54.8 ± 12.1 kg) undertook lower-body muscle structure assessment with ultrasonography and performed a; CMJ, SJ and an isomet-ric mid-thigh pull (IMTP). In addition, eccentric leg stiffness was calculated from variables of the CMJ and IMTP. Moderate to very large relationships (r = 0.46-0.73) were identified be-tween the thickness of the vastus lateralis (VL) and lateral gas-trocnemius (LG) muscles, and VL pennation angle and; peak force (PF) in the CMJ, SJ and IMTP. Additionally, moderate to large relationships (r = 0.37-0.59) were found between eccentric leg stiffness and; VL and LG thickness, VL pennation angle, and LG fascicle length, with a large relationship (r = 0.59) also present with IMTP PF. These results suggest that greater thick-ness of the VL and LG were related to improved maximal dy-namic and isometric strength, likely due to increased hypertro-phy of the extensor muscles. Furthermore, this increased thickness was related to greater eccentric leg stiffness, as the associated enhanced lower-body strength likely allowed for greater neuromuscular activation, and hence less compliance, during a stretch-shortening cycle

The effect of ball carrying on the sprinting speed of international rugby union players

Speed is considered to be a highly valuable ability in rugby union. One unique aspect of rugby is that players need to be effective at sprinting while carrying a rugby ball. Previous research reported that amateur club players were slower while sprinting with the ball, than without. The purpose of the current research was to examine how sprinting while carrying a ball affected the sprinting speed of international rugby players. Twenty-six international players performed 6 x 40 m sprints under three conditions: Ball One Hand (B1H), Ball Two Hands (B2H) and No Ball (NB). Timing gates were placed at the 0 m, 10 m, 30 m and the 40m mark of the sprint. The 0-10m was used to examine initial acceleration; 30-40 m was used to examine maximal velocity and the 10-30 m section to analyze the acceleration up to maximal velocity. Comparisons were also made between backs and forwards. Backs were found to be faster than forwards at each of the splits for the NB, B1H and B2H conditions (0.04 - 0.08 s,

Physiological Profile of Male Competitive and Recreational Surfers

Surfing consists of both high- and low-intensity paddling of varying durations, using both the aerobic and anaerobic systems. Surf-specific physiological studies lack adequate group sample sizes, and V[Combining Dot Above]O2peak values are yet to determine the differences between competitive and recreational surfers. The purpose of this study was therefore to provide a comprehensive physiological profile of both recreational and competitive surfers. This multisite study involved 62 male surfers, recreational (n = 47) and competitive (n = 15). Anthropometric measurements were conducted followed by dual-energy x-ray absorptiometry, anaerobic testing and finally aerobic testing. V[Combining Dot Above]O2peak was significantly greater in competitive surfers than in recreational surfers (M = 40.71 ± 3.28 vs. 31.25 ± 6.31 ml·kg·min, p \u3c 0.001). This was also paralleled for anaerobic power (M = 303.93 vs. 264.58 W) for competitive surfers. Arm span and lean total muscle mass was significantly (p ≤ 0.01) correlated with key performance variables (V[Combining Dot Above]O2peak and anaerobic power). No significant (p ≥ 0.05) correlations were revealed between season rank and each of the variables of interest (V[Combining Dot Above]O2peak and anaerobic power). Key performance variables (V[Combining Dot Above]O2peak and anaerobic power) are significantly higher in competitive surfers, indicating that this is both an adaptation and requirement in this cohort. This battery of physiological tests could be used as a screening tool to identify an athlete\u27s weaknesses or strengths. Coaches and clinicians could then select appropriate training regimes to address weaknesses

Scoring Analysis of the Men’s 2013 World Championship Tour of Surfing

The study compared scores obtained by the 10 highest and lowest ranked athletes on the men’s 2013 World Championship Tour (WCT) of surfing. Significant differences (p\u3c.001) were identified between the two groups’ average wave scores, average total scores and total heats competed. In addition, the average standard deviation (SD) of each surfer’s wave score was significantly different (p = .020) between the two groups. Significant moderate correlations were identified between athletes’ average placing and the SD of their wave scores (r = .596, p = .006), and total heat scores (r=.474, p=.035). Repeated measures ANOVA also revealed significant differences between heat scores obtained during the final and all previous rounds (p \u3c .001-.041). In conclusion, higher ranked surfers achieved higher wave scores and heat totals, and were more consistent in scoring. On average, a 1.04 point increase per wave score would allow a bottom 10 ranked surfer to reach the top 10, a small but impactful gain

RELEVANCE, RELIABILITY AND LIMITATIONS OF A DROP AND STICK LANDING ANALYSIS

The vertical force data from a drop and stick landing can be used to derive a number of variables. Previous studies have generally focused on the time to stabilization and peak force aspects, and issues related to reliability have been reported. This study investigated reliability for time to stabilisation, peak force, time to peak force, stiffness, rate of force dissipation, impulse and eccentric power (EP) among five professional elite surfing athletes. This data was also compared to data of aerial success in World Championship Tour competitions. The results revealed the best relationship between relative stiffness as well as eccentric power and completion rate of aerial manoeuvres. Further, eccentric power had the best reliability of the variables and may therefore be an interesting variable to study further

Workloads of Competitive Surfing: Work-to-Relief Ratios, Surf-Break Demands, and Updated Analysis

The study provides an in-depth descriptive and quantitative time-motion analysis of competitive surfing, using Global PositioningSystem (GPS) units and video synchronization, which serves toextend upon the results of Farley, Harris, and Kilding (Journal ofStrength and Conditioning Research, 26, 7 [2012]). In addition,comparisons between locations and surfers competing in thesame heats were performed. Global Positioning System andvideo data were collected from 41 male competitive surfers(23.266.1 years, 71610.3 kg, 177.266.4 cm) participatingin 3 professional domestic surfing events, with competitive heatsof 20-minute duration. Fifty data sets were analyzed across the 3competitions, with velocities and distances covered, proportionof time spent performing various surfing activities, and totalwork-to-relief ratio determined. Results revealed surfers paddled44% of the total time, followed by stationary periods (42%).Surfers performed at a significantly (p#0.05) higher work-to-relief ratio (1.7:1) at the Beach-break (an exposed beach) com-pared with point-break 1 and 2 (waves breaking around a rockypoint). Point-breaks 1 and 2 had longer continuous durations ofpaddling, with significantly longer rides at point-break 1 over theBeach-break (p#0.01) and point-break 2 (p#0.01). Theaverage maximal speed (24.8 km$h21) from point-break 2 wassignificantly faster than point-break 1 (p#0.01) and Beach-break (p#0.05). This information should influence surfing drills and conditioning methods to prepare these athletes for the disparate demands, such as training for a point-break competition involving longer durations of continuous paddling and short, high-intensity workloads for a Beach-break

Instability of Plastid DNA in the Nuclear Genome

Functional gene transfer from the plastid (chloroplast) and mitochondrial genomes to the nucleus has been an important driving force in eukaryotic evolution. Non-functional DNA transfer is far more frequent, and the frequency of such transfers from the plastid to the nucleus has been determined experimentally in tobacco using transplastomic lines containing, in their plastid genome, a kanamycin resistance gene (neo) readymade for nuclear expression. Contrary to expectations, non-Mendelian segregation of the kanamycin resistance phenotype is seen in progeny of some lines in which neo has been transferred to the nuclear genome. Here, we provide a detailed analysis of the instability of kanamycin resistance in nine of these lines, and we show that it is due to deletion of neo. Four lines showed instability with variation between progeny derived from different areas of the same plant, suggesting a loss of neo during somatic cell division. One line showed a consistent reduction in the proportion of kanamycin-resistant progeny, suggesting a loss of neo during meiosis, and the remaining four lines were relatively stable. To avoid genomic enlargement, the high frequency of plastid DNA integration into the nuclear genome necessitates a counterbalancing removal process. This is the first demonstration of such loss involving a high proportion of recent nuclear integrants. We propose that insertion, deletion, and rearrangement of plastid sequences in the nuclear genome are important evolutionary processes in the generation of novel nuclear genes. This work is also relevant in the context of transgenic plant research and crop production, because similar processes to those described here may be involved in the loss of plant transgenes