Over the years, Donnay has established a brand that focuses on producing arm friendly tennis racquets. I reached out to Donnay asking couple questions, about the methods, approach on design etc… when asked about the performance and a scientific stufy, they provided the independent study by Orthokinetic Labs, which Im posting below unedited.

The results of the first part of the first-ever independent Racket Shock & Injury Medical Study are in and they dramatically show that Donnay multi-solid core frames produce four times less shock & vibration time on ball contact than competitive hollow rackets from the four leading brands.

The study was conducted by OrthoKinetic Technologies, LLC, a leading independent firm in Shallotte, NC, that tests medical devices for regulatory and pre-clinical test strategies for FDA and CE submissions.

The Donnay racket, engineered for Arm Safe Performance, vibrated for less than 1/5 of a second on ball contact in the test, compared to an average of 7/10 of a second for the other models tested. That means a player hitting 180 balls in a typical tennis match is subjected to more than 111 seconds of shock & vibration dwell time with the other brands versus 32 seconds with the Donnay.

The importance of the study to players: They get a vibration every time they hit the ball and some of the shock is transmitted to the arm. The more prolonged the shock & vibration the more it can cause arm injuries. Results of the second part of the study – the amount of initial shock & vibration between Donnay and the other brands will be released next week.

The extent of frame vibration transmitted to the arm holding the racquet depends largely on how well it is dampened. Donnay’s solid-core XeneCore construction and manufacturing process acts as a super dampener to eliminate most all of the damaging vibrations.

In the old wood rackets, vibration disappeared quickly because it was dampened by the flex of the solid wood, but the new stiffer, lighter and hollow conventional frames do a poor job of snuffing out the vibrations, so they transfer this shaking to the arm that can stealthily sabotage the elbow, wrist, forearm and shoulder. The longer the vibration and the longer a player rallies the more the tendons are stressed. This constant stressing is how a coathanger is broken by bending it back and worth. Eventually, fatigue can cause tissues to snap, even without any tremendous force.

Hollow racquets with their poor dampening properties cause pain (think of hitting a baseball with the hollow aluminum baseball bat on a chilly day).

For years the tennis industry has laid the blame for arm injuries on poor stroking techniques, conveniently diverting scrutiny from the design of racquets, but hollow, stiff, ultralight head-heavy racquets are more to blame. As conventional racquets have grown lighter and stiffer the number of players suffering from arm and elbow pain has also risen dramatically. The cause is no longer primarily related to mechanics, but rather to the equipment itself.

In addition to Donnay’s solid-core technology and consistent with its mantra of “Arm Safe Performance,” Donnay’s specs reflect more arm-friendly properties that include more mass, head-light balances and flexible frames.

The release of the first part of the study, entitled “Tissue Stress Magnitude,” is great news for your retail dealers since as many as one-in-four of their customers are currently experiencing some form of arm pain and are looking for racquets that help them recover quickly or play through the pain. That’s when power and control take a backseat.

Because if you’re trying to play hurt, you’re not playing well at all.

Best wishes for the holidays and we’ll keep you breast with the rest of the study, along with a detailed report from next week from OrthoKinetic Technologies.