Celebrating Olympic Divers

In this blog, I am going to bring together two topics that might not seem to be an obvious pair - seabirds and Olympic divers. They are related by the physical challenges they face.

This morning, I was watching the first day of the 2024 Olympic aquatics competition. The big news was that the British women's team in synchronized 3-meter springboard diving just got the first British medal during these games. The bronze medal was the first British women's diving medal since the 1960 Olympic Games in Rome. The current medal awarded to these two amazing women athletes was remarkable for another reason as well. One of the team members, Scarlett Mew Jensen mentioned during the interview that followed their award ceremony that she had suffered a partial fracture of her back just two months ago. Even the sports commentators were surprised that she was able to compete so soon after such a major injury. This reminded me of how all Olympic athletes are pushing the human body to the limits of its capacity and this is starkly apparent in the human beings who jump from high platforms to dive head first into the water. 

Imagine standing on an Olympic diving platform, some 10 meters (33 ft) above the water, contemplating whether to dive head first or feet first into the water. As they say, it is not the fall that is the problem, it is the landing, or in this case the moment you hit the water's surface. We have all seen the beautiful entries as Olympic divers plunge headfirst into the water. They hit the water surface at a speed of 50 km/hr (31 mph). To accomplish this feat requires years of training both to avoid injury and to enter the water as smoothly as possible. 

But, how does this relate to seabirds you are probably wondering….

This brings me to the Sulidae family of seabirds, the plunge-diving Boobies and Gannets. Their diving technique brings to mind the challenges faced by Olympic athletes. I have been thinking about this topic this week both because it is the start of the 2024 Summer Olympics and because I am in the midst of researching seabird diving physiology for an important project. I am currently involved in background research to support the curriculum and development of the next children’s book in the seabird series. This project is a collaboration between the Kula Naiʻa Foundation and the Hawaiʻi Wildlife Center. For the current book, we are focusing on the red-footed booby (‘Ā in Hawaiian; scientific name Sula sula). This species is the smallest member of a seabird family that includes 7 species of boobies and 3 species of gannets - Boobies are generally found in tropical and subtropical areas, while gannets are generally found in temperate and arctic waters. The Red-footed booby is one of the three Sulidae species commonly seen in Hawaiian water. 

Let’s return to the human diver for a moment. When entering the water, the problems that come up are mostly due to water being over 800 times denser than air and, to a lesser extent, the water surface tension, due to the bonds between water molecules. As a result, the water surface will feel very hard on impact. All Olympic divers enter the water head first, so they extend their hands and arms overhead to create a protective wedge to break through the surface tension and withstand the rapid increase in density, as they enter the water at a very high speed - for a 180 cm (6’) tall person, the shoulders would enter the water less than 30 milliseconds after the hands hit the surface. 

Maintaining this wedge shaped arm and hand position is very important for a safe dive, as well as to minimize the resulting splash created by the entry into the water (See this Link). Holding the arms and shoulders in position to maintain this wedge shape and minimize injury becomes increasingly difficult at greater heights than 10 meters. This is why Olympic dives are limited to 10 meters. Most competitive diving injuries from this height affect the upper body/trunk, including shoulders, spine, hands, head, and neck, with overuse as a key factor. Of these, shoulder injuries and injuries to the head, face and neck are often sustained when entering the water, while injuries to hands, wrists and spine are more due to the gymnastic/acrobatic elements of the sport. For comparison, looking at other Olympic sports the most common injuries for runners are to their legs and feet, while gymnasts suffer injuries to their knees, ankles, elbows, shoulders and wrists. Most of these fall into the category of repetitive use type of injury. The risk of injury posed by striking the water adds another dimension to the challenges faced by divers. There is a gender difference seen perhaps because men are larger and heavier. The proportion of all injuries due to surface contact with the water varies between males and females, with males sustaining a higher proportion (32.3 ​%) of injuries this way than female divers (20 ​%). 

This is why it is critical for both birds and humans to line up the joints between all the bones in their neck and shoulder regions, and in the arms in humans, as well as, having all their skeletal muscles fully engaged at the point of impact. Humans must learn to do this through specific training, including strengthening the muscles to be able to take the extra strain upon impact with the water.

The next blog will explore more about how the Gannets and Boobies can repeatedly plunge-dive into the water from 30 meters, 3 times the height Olympic divers dive from, without sustaining injuries.

References:

Wnag, et al. 2024. Attention to competitive diving injuries: A systematic review. Medicine in Novel Technology and Devices, Volume 23, September 2024, 100316

Curry, B.M. et al. 2024. Diving Into the Health Problems of Competitive Divers: A Systematic Review of Injuries and Illnesses in Pre-elite and Elite Diving Athletes. Sports Health: A Multidisciplinary Approach, June 3, 2024, https://doi.org/10.1177/19417381241255329

Charpy, S. et al. 2023. Epidemiology of injuries in elite Women’s Artistic Gymnastics: a retrospective analysis of six seasons, BMJ Open Sport & Exercise Medicine 2023;9:e001721. doi:10.1136/ bmjsem-2023-001721

Kelly, S. et al. 2022. Injury and illness in Elite Athletics: A prospective Cohort Study Over Three Seasons. IJSPT 2022: 17(3): 420-33. doi:10.26603/001c.32589