By Dr. G. John Mullen, PT, DPT, CSCS of Swimming Science, Owner of COR PT , Creator of Swimmer's Shoulder System, Swimming Science Research Review, Swimming Troubleshooting System , and Mobility for Swimmers System , Swimming World correspondent
Courtesy of: Rob Schumacher - USA Today Sports
Courtesy of: Rob Schumacher - USA Today Sports
SANTA CLARA, California, May 21. IN diving, athletes need to perform both fluid and aesthetic movements. The diver wants to maximize height of the flight phase following takeoff (Carter 1986). The higher the diver is in the air before reaching the water, the greater number of twists and somersaults the body can perform.
Athletes dive from a springboard or a platform, and the type of surface can affect the amount of time a diver has in the air. The springboard is more accommodating than the platform and allows the diver to reach a greater height. A diver usually executes two different takeoffs on springboard and platform: front and back. Movements during a springboard takeoff are performed at a slower rate than on the platform because an athlete must synchronize arm swing and knee bend with the oscillation of the board (Carter 1986). A diver performing a platform takeoff must implement an arm swing and knee bend as fast as possible in order to increase the height and speed necessary to complete a dive.
Steps for the Front Approach
The intricate maneuvers during a front approach require strength, agility, balance, timing, quickness and courage (Carter 1986). For a front dive, the takeoff includes an approach, a hurdle, and a press. On a platform a front dive can start from a standing position, with no depression of the surface. An important factor in the height achieved upon leaving the springboard is the ability to time the descent from the hurdle with that of the board. This technique allows the diver to "ride" the board for a press. Working against the board has consequences for both performance and injury risk.
Three reasons why you have knee pain during your takeoff
The injury-producing forces during the takeoff are related to jumping and deceleration. These commonly involve the extensor mechanism of the knee. The most common injuries related to this part of the dive are patellar tendinitis, patellar tracking problems, quadriceps tendinitis, Jumper's knee and patellofemoral compression syndrome commonly caused by repetitive stress placed on the patellar or quadriceps tendon during jumping (Carter 1986). Vertical jump ability, as well as jumping and landing technique, are believed to influence tendon loading.
If our athletes are feeling pain in their knees from jumping, we first analyze their diving biomechanics, then remove any extra stressed placed on the knee. Here are three common flaws which increase knee stress during diving:
Knee Cave: If the diver has reduced gluteal activity, a greater degree of hip internal rotation results, caving the knees and increasing knee torque. This position stresses the medial and anterior compartments of the knee. Also, the lack of gluteal activity decreases the jump height potential on the approach.
Trunk Flexion: If the athlete is bowing during the takeoff, they aren't maximizing their hip strength. Hip flexor tightness or weak gluteals can cause this position, both increasing stress on the anterior parts of the body due to the weight shift. Instead, breaking from the hips and knees during the takeoff helps shift one's body weight toward their heels, increasing the demand on the posterior compartments (hips).
Forward Knees: If the diver's knees come over their toes during the takeoff they are overly stressing their patellar tendon. When we teach our athletes how to squat, we have them stand approximately shoulder width apart with toes straight or
slightly out. Next, break from the hips and knees while driving the hips backwards. When you are about halfway down, begin pushing your knees out and opening up your groin. At this point, your hips and glutes should be pushed back, with your mid-back directly over your heels. On return, keep pushing the knees out until your return to the starting position.
Improving biomechanics is one area for reducing knee stress, pain and injury. Luckily, these biomechanics also help increase takeoff height and diving potential.
If someone is having pain, further evaluation from a physical therapist is likely. Treatments of these injuries, depending on the severity of the injury, consists of strengthening, motor control, and improving muscular imbalances.
Dive correctly, stay healthy, and have fun!
Prevention of springboard and platform diving injuries. Clin Sports Med.
Manheim, Carol J. (2008). The myofascial release manual (4th ed.). Thorofare, New Jersey: Slack. ISBN 978-1556428357
Dr. G. John Mullen received his Doctorate in Physical Therapy from the University of Southern California and a Bachelor of Science of Health from Purdue University. He is the owner of COR PT, strength and conditioning consultant, creator of the Swimmer's Shoulder System, and chief editor of the Swimming Science Research Review.