This study compared the conventional track and a new one-handed track start in elite age group swimmers to determine if the new technique had biomechanical implications on dive performance. Five male and seven female GB national qualifiers participated (mean ± SD: age 16.7 ± 1.9 years, stretched stature 1.76 ± 0.8 m, body mass 67.4 ± 7.9 kg) and were assigned to a control group (n = 6) or an intervention group (n = 6) that learned the new one-handed dive technique. All swimmers underwent a 4-week intervention comprising 12 ± 3 thirty-minute training sessions. Video cameras synchronized with an audible signal and timing suite captured temporal and kinematic data. A portable force plate and load cell handrail mounted to a swim starting block collected force data over 3 trials of each technique. A MANCOVA identified Block Time (BT), Flight Time (FT), Peak Horizontal Force of the lower limbs (PHF) and Horizontal Velocity at Take-off (Vx) as covariates. During the 10-m swim trial, significant differences were found in Time to 10 m (TT10m), Total Time (TT), Peak Vertical Force (PVF), Flight Distance (FD), and Horizontal Velocity at Take-off (Vx) (p < .05). Results indicated that the conventional track start method was faster over 10 m, and therefore may be seen as a superior start after a short intervention. During training, swimmers and coaches should focus on the most statistically significant dive performance variables: peak horizontal force and velocity at take-off, block and flight time.
H. Galbraith, J. Scurr, C. Hencken, L. Wood and P. Graham-Smith
Deborah L. Feltz, Graig M. Chow and Teri J. Hepler
The Feltz (1982) path analysis of the relationship between diving efficacy and performance showed that, over trials, past performance was a stronger predictor than self-efficacy of performance. Bandura (1997) criticized the study as statistically “overcontrolling” for past performance by using raw past performance scores along with self-efficacy as predictors of performance. He suggests residualizing past performance by regressing the raw scores on self-efficacy and entering them into the model to remove prior contributions of self-efficacy imbedded in past performance scores. To resolve this controversy, we reanalyzed the Feltz data using three statistical models: raw past performance, residual past performance, and a method that residualizes past performance and self-efficacy. Results revealed that self-efficacy was a stronger predictor of performance in both residualized models than in the raw past performance model. Furthermore, the influence of past performance on future performance was weaker when the residualized methods were conducted.
Anna Melin, Monica Klungland Torstveit, Louise Burke, Saul Marks and Jorunn Sundgot-Borgen
Disordered eating behavior (DE) and eating disorders (EDs) are of great concern because of their associations with physical and mental health risks and, in the case of athletes, impaired performance. The syndrome originally known as the Female Athlete Triad, which focused on the interaction of energy availability, reproductive function, and bone health in female athletes, has recently been expanded to recognize that Relative Energy Deficiency in Sport (RED-S) has a broader range of negative effects on body systems with functional impairments in both male and female athletes. Athletes in leanness-demanding sports have an increased risk for RED-S and for developing EDs/DE. Special risk factors in aquatic sports related to weight and body composition management include the wearing of skimpy and tight-fitting bathing suits, and in the case of diving and synchronized swimming, the involvement of subjective judgments of performance. The reported prevalence of DE and EDs in athletic populations, including athletes from aquatic sports, ranges from 18 to 45% in female athletes and from 0 to 28% in male athletes. To prevent EDs, aquatic athletes should practice healthy eating behavior at all periods of development pathway, and coaches and members of the athletes’ health care team should be able to recognize early symptoms indicating risk for energy deficiency, DE, and EDs. Coaches and leaders must accept that DE/EDs can be a problem in aquatic disciplines and that openness regarding this challenge is important.
Peter R.E. Crocker and David R. Leclerc
This study investigated Griffin and Keogh's movement confidence model. This model holds that movement confidence is determined by the joint influence of perception of ability, the potential for enjoying moving, and the potential for harm. Undergraduate students, 20 males and 20 females, attempted three modified back dives. Before each dive, subjects completed measures on perceived diving confidence, perceived diving ability, potential for enjoying the dive, and potential for harm. Scale internal consistency ranged from «=.62 to «=.85. Regression analyses found a three-term model was a significant predictor of movement confidence (R2s=.54, .67, .71, for Dives 1, 2, and 3, respectively). However, hierarchical regression analyses indicated only potential for physical harm made a significant, unique contribution. The data highlight the importance of perceived movement sensations in influencing the appraisal of movement confidence.
Dan Benardot, Wes Zimmermann, Gregory R. Cox and Saul Marks
Competitive diving involves grace, power, balance, and flexibility, which all require satisfying daily energy and nutrient needs. Divers are short, well-muscled, and lean, giving them a distinct biomechanical advantage. Although little diving-specific nutrition research on performance and health outcomes exists, there is concern that divers are excessively focused on body weight and composition, which may result in reduced dietary intake to achieve desired physique goals. This will result in low energy availability, which may have a negative impact on their power-to-weight ratio and health risks. Evidence is increasing that restrictive dietary practices leading to low energy availability also result in micronutrient deficiencies, premature fatigue, frequent injuries, and poor athletic performance. On the basis of daily training demands, estimated energy requirements for male and female divers are 3,500 kcal and 2,650 kcal, respectively. Divers should consume a diet that provides 3–8 g/kg/day of carbohydrate, with the higher values accommodating growth and development. Total daily protein intake (1.2–1.7 g/kg) should be spread evenly throughout the day in 20 to 30 g amounts and timed appropriately after training sessions. Divers should consume nutrient-dense foods and fluids and, with medical supervision, certain dietary supplements (i.e., calcium and iron) may be advisable. Although sweat loss during indoor training is relatively low, divers should follow appropriate fluid-intake strategies to accommodate anticipated sweat losses in hot and humid outdoor settings. A multidisciplinary sports medicine team should be integral to the daily training environment, and suitable foods and fluids should be made available during prolonged practices and competitions.
Ross H. Sanders and Barry D. Wilson
This study investigated factors contributing to the maximum height achieved by divers after takeoff from the 3m springboard. Twelve elite male divers and 12 elite female divers competing in the 1986 Australian National Championships were filmed using high-speed cinematography. Kinematic and kinetic data for the takeoff phase were derived from the digitized film. Variables analyzed included center of gravity (CG) displacement and velocity, the acceleration of the CG relative to the springboard, and the components of mechanical energy contributing to height achieved by the diver’s CG. Body orientation was described in terms of the angles at the hip, knee, and ankle, and whole body angle of lean. Comparison of timing differences among dive groups and divers was aided by normalizing the data with respect to time. It was found that the height achieved was highly dependent on the rotational requirements of the dive, with males achieving greater heights than females. Divers who achieve good height compared to other divers performing the same dive are characterized by a large vertical velocity at touchdown from the hurdle and a minimization of hip flexion (forward dives) and knee flextion (reverse dives) at takeoff.
Agnès Bonnet, Lydia Fernandez, Annie Piolat and Jean-Louis Pedinielli
The notion of risk-taking implies a cognitive process that determines the level of risk involved in a particular activity or task. This risk appraisal process gives rise to emotional responses, including anxious arousal and changes in mood, which may play a significant role in risk-related decision making. This study examines how emotional responses to the perceived risk of a scuba-diving injury contribute to divers’ behavior, as well as the ways that risk taking or non-risk taking behavior, in turn, affects emotional states. The study sample consisted of 131 divers (risk takers and non-risk takers), who either had or had not been in a previous diving accident. Divers’ emotional states were assessed immediately prior to diving, as well as immediately following a dive. Results indicated presence of subjective emotional experiences that are specific to whether a risk has been perceived and whether a risk has been taken. Important differences in emotion regulation were also found between divers who typically take risks and those who do not.
Ross H. Sanders and Barry D. Wilson
This study investigated the in-flight rotation of elite 3m springboard divers by determining the angular momentum requirement about the transverse axis through the divers center of gravity (somersault axis) required to perform a forward 1 1/2 somersault with and without twist. Three elite male divers competing in the 1982 Commonwealth Games were filmed using high-speed cinematography while performing the forward 1 1/2 somersault in the pike position and the forward 1 1/2 somersault with one twist in a free position. The film was digitized to provide a kinematic description of each dive. An inclined axis technique appeared to be the predominant means of producing twist after takeoff from the board. The angular momentum about the somersault axis after takeoff was greater for the forward 1 1/2 somersault with twist than the forward 1 1/2 somersault without twist for all three divers. The difference in angular momentum between the two dives of each diver ranged from 6% to 19%. The most observable difference between the dives during the preflight phases was the degree of hip flexion at takeoff. There was more hip flexion at takeoff in 5132D than 103B for all three divers. This difference ranged from 9° to 18° (mean = 14°).
Karen Murtaugh and Doris I. Miller
To determine strategies for initiating rotation in armstand back and reverse triple somersaults tuck dives from the 10-m platform, videotaped records of 17 elite male divers performing in competitions between 1995 and 1999 were analyzed. Linear and angular momenta at last contact were similar for both dives. Although the lower extremity actions were comparable, they occurred significantly earlier (p < .05) in reverse triple takeoffs, allowing divers to enter the tuck more quickly. As divers lean, the moment arm of the vertical platform reaction force increases with respect to the CG. The vertical platform reaction force moment promotes back and opposes reverse somersaulting angular momentum. Meanwhile, the horizontal platform reaction force moment promotes reverse and opposes back somersaulting angular momentum. Consequently, divers performing reverse triples maintained a more vertical trunk position during the early part of the takeoff, while those executing back triples leaned further before initiating lower and upper extremity actions to exert force against the platform. Since the strategy for reverse rotation may result in the head passing close to the platform and there is very little to gain in degree of difficulty, it is recommended that competitors execute back rather than reverse somersaulting armstand dives.
Peter L. Davidson, Brendan Mahar, David J. Chalmers and Barry D. Wilson
This study was to determine estimates of the stiffness and damping properties of the wrist and shoulder in children by examining wrist impacts on the outstretched hand in selected gymnastic activities. The influence of age, mass, and wrist and torso impact velocity on the stiffness and damping properties were also examined. Fourteen young gymnasts (ages 8 to 15 yrs) were videotaped while performing back-handspring trials or dive-rolls. Kinematic and ground reaction analysis provided input for computer simulation of the body as a rheological model with appropriate stiffness and damping. A significant positive linear relationship was obtained between wrist damping in dive rolls and age, mass, and wrist and torso impact velocity, while shoulder damping in the back-handsprings had a significant positive linear relationship with body mass. This new information on stiffness and damping at the shoulder and the wrist in children enables realistic mathematical modeling of children's physical responses to hand impact in falls. This is significant because modeling studies can now be used as an alternative to epidemiological studies to evaluate measures aimed at reducing injuries in gymnastics and other activities involving impact to the upper extremity.