Pressures Exerted on the Hook of the Hamate in Collegiate Baseball Players: A Comparison of Grips, With Emphasis on Fracture Prevention.

BACKGROUND: Variations in batting technique may put baseball players at increased risk of hook of the hamate fractures. A better comprehension of the mechanism of such fractures is needed. PURPOSE/HYPOTHESIS: The purpose of the study was to compare 2 different grip types to quantify the pressures exerted on the hook of the hamate during batting. It was hypothesized that when compared with the conventional batting style, players holding the knob of the bat in the palm of the hand (termed the "palmar hamate grip") would have higher pressures exerted on the hook of the hamate. STUDY DESIGN: Controlled laboratory study. METHODS: Athletes were recruited for participation on a volunteer basis from the rosters of 2 National Collegiate Athletic Association Division I baseball teams and were divided into 2 groups based on their usual grip type. A force sensor system was applied to the nondominant hand of each participating player, with the central portion of the sensing mechanism placed on the batting glove directly over the hook of the hamate. All players used the same batting glove, which transmitted data from the sensor to a laptop computer. Measurements were collected on consecutive hits at a standardized distance using a ball machine at 70 mph. RESULTS: Nine collegiate baseball players underwent testing (5 players exclusively used the conventional grip, 3 players exclusively used the palmar hamate grip, and 1 player naturally alternated between the 2 grip types). The palmar hamate grip demonstrated a 366% increase in pressure exerted on the sensor overlying the hook of the hamate when compared with the conventional batting grip (536.42 kPa [95% confidence interval, 419.39-653.44 kPa] vs 115.84 kPa [95% confidence interval, 96.97-135.10 kPa]). The player who used both grips demonstrated significantly higher maximum pressure when using the palmar hamate versus conventional grip (482.90 vs 142.40 kPa; t = 6.95; P < .0001). CONCLUSION: Use of the palmar hamate grip may increase the risk of hook of the hamate fracture in National Collegiate Athletic Association Division I baseball players. CLINICAL RELEVANCE: Educating players on the risks associated with the palmar hamate grip may prevent injury and minimize time out of competition.