Competitive Swim Starts

Reports from high school and collegiate sports suggest that in competitive swimming, most catastrophic injuries occur when swimmers are performing competitive racing starts (Mueller & Cantu, 2007). As swimming participation in this country continues to remain at high levels (286,147 USA Swimming registered athletes; USA Swimming, 2009) and new facilities are built, there is an obvious need to review all aspects of safety within the sport so as to ensure that rules and regulations are based upon sound safety practices. Since the racing start appears to be the aspect of the sport that is the most inherently risky, it is critical that we carefully examine the variables pertaining to the racing start as a means of identifying the level of risk they represent.

The U.S. Consumer Product Safety Commission (1989) reported that “approximately 700 spinal cord diving injuries are estimated to occur in the U.S. annually as a result of recreational diving into residential pools, public pools and other bodies of water” and “the estimated annual cost of these [diving] injuries could total $1.4-3.5 billion.” Due to the potentially catastrophic nature of injuries sustained during diving, the frequency with which these injuries occur, and the long-term cost of medical treatment for these injuries, the ‘diving problem’ is one that warrants continued investigation. 

USA Swimming (USAS), the major governing body of competitive swimming in the United States, was previously interested in learning more about a particular subset of diving injuries: dives from a starting block. Specifically, USAS wanted to learn more about the factors that affect the outcomes of competitive racing starts (i.e., head depths and head speeds) in an effort to establish empirically-based racing start regulations. In order to do so, USAS provided our research group with a grant to perform a multi-phase project on the competitive swim start.

To date, we have examined the effect of age, water depth, block height, and start type on head depth and speed during the execution of a swim start.  Additionally, we studied the ability of competitive swimmers of different ages and skill levels to control the depth of their starts. Finally, we recently published articles on teaching practices for competitive racing starts and intra-individual head depth variability during the swim start.

We are currently preparing our final two manuscripts from this multi-phase project on competitive swim start safety. The first of these two manuscripts is on ‘worst-case scenario’ racing starts in which we analyze vertical head velocity of swimmers when they enter the water at a steep angle and travel directly toward the pool bottom in a diving well. We compare these obtained vertical head velocities at predetermined depths to critical threshold speeds from the literature known to cause cervical spine failure. This will enable us to make recommendations as to the appropriate minimum water depth when swimmers execute starts. The second of the two manuscripts on which we are working is an invited review article on competitive swim start safety. We hope to have these articles submitted for publication by the end of the spring semester of 2012 and in print by the end of the winter semester of 2013. 

We feel that our research has made a significant contribution to the field as two national governing bodies in the sport, USAS and the National Federation of State High School Associations (NFHS), have made rule changes as a direct result of our research findings. However, even after we finish our current data, we feel that additional research needs to be done. Because of the potentially catastrophic nature of injuries occurring when swimmers contact the pool bottom during a racing start, we believe that the rules and regulations regarding minimum water depth for competitive swim starts should be based on empirical evidence.

Currently, USAS requires a water depth of 1.22 m (4 ft) in order for swimmers to be permitted to execute starts from a starting block. However, the Center for Disease Control and Prevention (CDC) is attempting to gain approval for the Model Aquatic Health Code: A National Model Swimming Pool and Spa Code (MAHC). This model would have a huge impact on aquatic facility design in the United States because part of the code would mandate a water depth of 2 meters (6.6 feet) for swimmers to be permitted to execute starts from starting blocks. USAS’s current minimum water depth (1.22 m) and the CDC’s proposed minimum depth (2.0 m) are seemingly arbitrary choices though. We hope that our research will be used to adopt minimum water requirements that are based on empirical evidence.

Publications

Cornett, A.C., White, J.C., Wright, B.V., Willmott, A.P, & Stager, J.M. (2010). Racing start safety: Head depth and head speed during competitive starts into a water depth of 1.22m. International Journal of Aquatic Research and Education, 4, 365-378.

Cornett, A.C., White, J.C., Wright, B.V., Willmott, A.P, & Stager, J.M. (2011). Racing start safety: Head depth and head speed during competitive swim starts into a water depth of 2.29m. International Journal of Aquatic Research and Education, 5, 14-31.

Cornett, A.C., White, J.C., Wright, B.V., Willmott, A.P, & Stager, J.M. (2011). Water depth influences the head depth of competitive racing starts. International Journal of Aquatic Research and Education, 5, 32-41.

Cornett, A.C., White, J.C., Wright, B.V., Willmott, A.P, & Stager, J.M. (2011). Block height influences the head depth of competitive racing starts. International Journal of Aquatic Research and Education, 5, 174-186.

White, J.C., Cornett, A.C., Wright, B.V., Willmott, A.P, & Stager, J.M. (2011). Competitive swimmers modify racing start depth upon request. International Journal of Aquatic Research and Education, 5, 187-198.

Cornett, A.C., White, J.C., Wright, B.V., Willmott, A.P, & Stager, J.M. (2011). Racing start safety: Head depth and head speed during competitive backstroke starts. International Journal of Aquatic Research and Education, 5, 389-401.

Cornett, A.C., White, J.C., Wright, B.V., Willmott, A.P, & Stager, J.M. (2012). Start depth modification by adolescent competitive swimmers. International Journal of Aquatic Research and Education, 6, 68-79.

Cornett, A.C., White, J.C., Wright, B.V., & Stager, J.M. (2012). Teaching competitive racing starts: Practices and opinions of professional swim coaches. International Journal of Aquatic Research and Education, 6, 156-170.

Cornett, A.C., Naganobori, H., & Stager, J.M. (2012). Intra-individual head depth variability during the competitive swim start. International Journal of Aquatic Research and Education, 6, 350-363.