Mitts still leave catchers vulnerable to hand damage

Catchers showed more abnormal ultrasounds in the ulnar artery of gloved hands.

Using a catcher’s mitt may not provide enough defense against hand injury, according to researchers at Wake Forest University Baptist Medical Center.

In their study, investigators found that 31% of healthy, professional baseball players had weakness, pain, numbness or tingling in their hands. Catchers were most affected by hand symptoms, with 44% reporting weakness vs. 7% of pitchers and 17% of both infielders and outfielders, and despite more catchers additionally wearing batting gloves under their mitts (P<.0001).

“We found signs of early blood vessel damage that could lead to significant symptoms and could end a player’s career,” T. Adam Ginn, MD, said in a press release. “The glove’s current design does not protect the hand from trauma.”

The study, published in the American edition of Journal of Bone & Joint Surgery, included 36 minor league players. The group consisted of 15 pitchers, nine catchers, seven outfielders and five infielders from North Carolina. After performing physical exams, the researchers noted visual signs of trauma. They also used ring sizers commonly used by jewelers to compare between hypertrophic and normal fingers.

Overall, researchers found that 11 players reported hand symptoms, but found “no correlation between the prevalence of symptoms and the number of years in baseball (P=.58) or the number of years at the position (P=.49),” the study authors said.

Changes consistent with trauma

But catchers — who may take more than 300 pitches each day — reported most symptoms, particularly in mitted hands compared to throwing hands (P<.05). Additionally, only catchers recalled having symptoms at rest, according to the study.

Similarly, only catchers showed hypertrophy in the index finger (P<.0001), with the index finger on the gloved hand being nearly two ring sizes larger than that of the throwing hand (P<.01), the authors noted.

Vascular testing illustrated some variability between groups. “Compared with all other players, catchers had a significantly greater prevalence of abnormal Doppler signals in the ulnar artery at Guyon’s canal in the gloved hand (P<.01),” the researchers wrote. Catchers’ ring fingers also demonstrated lower brachial indices against other players. Yet, researchers found no differences between abnormal timed Allen findings, player position or gloved hands, the authors said.

The current structure of catchers’ mitts directs balls to the webbing base. “This location is an area where digital nerves and vessels are relatively vulnerable, which may explain the high prevalence of symptoms, hypertrophy and vascular changes in the index finger of the gloved hand ...,” they said.

“Despite well-padded catchers’ mitts and the use of additional padding, the catchers examined in this study continue to demonstrate changes to the gloved index finger consistent with trauma,” Ginn said in the press release. “There should be further study into glove design,” he added.

For more information:
Ginn TA, Smith AM, Snyder JR, et al. Vascular changes of the hand in professional baseball players with emphasis on digital ischemia in catchers. J Bone Joint Surg Am. 2005;87:1464-1469.