PLEASE NOTE: The medical opinions in USTA.com's Ask the High Performance Lab are responses intended for the average player. Please consult with your primary physician before beginning any new exercise program.
Dr. Howard Brody
|Howard Brody© USTA|
is an emeritus professor of physics at the University of Pennsylvania. He played varsity tennis at MIT and earned his doctoral degree from Cal Tech. Dr. Brody has written many articles and given many presentations on the “physics and technology of tennis.” Professor Brody serves the sport of tennis in many ways; He is a member the International Tennis Federation Technical Commission, the USTA Sports Science Committee and Technical Committee, science advisor to the Professional Tennis Registry, technical advisor to the United States Racquet Stringers Association, and sits on the technical advisory panel of Tennis Magazine. He has also received the USPTR Plagenhoef award for sports science in 1996 and the International Tennis Hall of Fame Educational Merit Award for the year 2000.
At the 2003 Tennis Science and Technology Congress, the International Tennis Federation, in conjunction with CISLunar, gave a prize for the best paper presented and named it the “Howard Brody Award” for his service to tennis. His book Tennis Science for Tennis Players and The Physics and Technology of Tennis are also great resources for coaches looking for more information on sport science and technology in tennis.
Q: A few months ago I switched to a new racket. It's a bit heavier than my last racket but it is the next generation of what I had. Since getting the racket I occasionally feel tinges of pain in my wrist, but it never lasts for more than a few minutes - usually during warm-up. The other day, however, my wrist area really hurt. I saw an orthopedist who ruled out major problems and said it was tendonitis. I have been wearing a wrist brace and icing it and hope to be hitting in a few days. The big questions are "How much of this is because of the racket? Do a few ounces make a huge difference?"
A. It may not be because of the new racket. To see if it is the new racket, try the following. After your wrist heals, start off with your old racket, then switch to the new one. A racket weighs about 10 to 11 ounces, so a "new" one will not be heavier by "a few ounces." It could be that the new racket is stiffer, which might cause a problem. It could be that the new racket is strung tighter than the old one - which may have originally been strung tightly but now the tension in the old frame has relaxed to a much lower value. It may be that by switching rackets you also effectively switched to higher tension and stiffer frame.
Q: How does string tension impact play? Is it true that I can hit the ball with more power with a higher string tension?
A: Lower tension will give you about 1% more ball speed. This may not seem like much (a ball previously hit at 65 mph would be increased to 65.65 mph) but just that 1% will add about one (1) extra foot to the length of your groundstrokes. If a shot you used to hit landed 1/2 foot inside the baseline, adding 1% to the ball speed will result in the shot sailing long by about half a foot (if all else is held constant).
Q: Is luxilon a better string than gut? Does it have more playability? Is it more powerful?
A. The jury is still out on Luxilon. It seems to be more durable and it may provide just a little bit more spin on the ball.
Q: How does a racket's length influence play? Does the longer body help a baseliner or the server?
A. The extra length can be a benefit to servers, but only IF THEY TAKE ADVANTAGE OF IT. The extra length may allow you to get in an extra first serve or two per match. The baseline player will have a slightly longer reach. However, players will have to re-learn where to hit the ball on the head if they switch to a longer frame.
Q: If you play with a longbody are you more prone to becoming injured?
A. A longer frame has its Center of Percussion (minimum shock and jar point) and its NODE (minimum vibration point) at a slightly different location from the hand. If you go to a longer racket and still hit the ball at the same distance from your hand, you may feel a bit more vibration, shock, and jar.
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