The Effect of the Crow Hop on Elbow Stress During an Interval Throwing Program

Abstract

Background: Postoperative rehabilitation protocols after ulnar collateral ligament (UCL) reconstruction typically involve a structured interval throwing program. In an effort to minimize torque placed on the UCL, athletes are often instructed to throw with a crow hop, even at short throwing distances. However, the effect of the crow hop on medial elbow stress is unknown. Purpose/Hypothesis: The purpose was to determine whether elbow stress differs with and without a crow hop across the throwing distances of a typical interval throwing program. We hypothesized that crow hop throws would generate lower torque on the elbow than standing throws at each distance of the interval throwing program. Study Design: Controlled laboratory study. Methods: Healthy high school and collegiate pitchers and position players were recruited from the surrounding area. Each player was outfitted with a wearable athletic sleeve and device that recorded elbow torque (Newton-meters), arm slot (degrees), arm speed (revolutions per minute), and shoulder rotation (degrees). Ball velocity (miles per hour) was measured using a radar gun. Players were instructed to perform 3 crow hop throws and 3 standing throws at distances of 30, 45, 60, 90, 120, 150, and 180 feet. A repeated measures analysis of variance was used to compare ball velocity, elbow torque, arm slot, arm speed, and shoulder rotation between crow hop and standing throws at each throwing distance. Results: Twenty athletes participated in this study (average age, 17.8 years; range, 15-25 years). The average medial elbow torque increased at each distance for both crow hop and standing throws at distances of 30, 45, 60, and 90 feet ( P < .05), after which there were no significant increases in elbow torque ( P > .05). The average torque was higher for crow hop throws than standing throws at distances of 30 feet (13.9 N·m vs 12.0 N·m; P = .002), 45 feet (21.8 N·m vs 19.3 N·m; P = .005), and 60 feet (28.0 N·m vs 24.5 N·m; P = .02). Conclusion: Crow hop throws generated greater medial elbow torque than standing throws at distances up to 60 feet; however, there were no differences in elbow torque at distances greater than 60 feet between the 2 throw types. For both crow hop and standing throws, elbow stress increased at each distance interval up to 90 feet before plateauing at distances greater than 90 feet. The crow hop throwing technique does not reduce medial elbow stress during a simulated interval throwing program, and it may actually increase torque at shorter throwing distances. Clinical Relevance: The results of our study indicate that it would be prudent for players to initially perform standing throws at shorter distances and only later be allowed to employ a natural crow hop at greater distances to minimize torque placed on the medial elbow during UCL rehabilitation protocols.

The Effect of the Crow Hop on Elbow Stress During an Interval Throwing Program: Response

“…We would like to thank the Journal for the opportunity to respond to the Letter to the Editor by Wong et al regarding our recently published study entitled ''The Effect of the Crow Hop on Elbow Stress During an Interval Throwing Program.'' 5 We appreciate the recognition of effort by the letter authors regarding our study and the importance of conducting such studies on overhead athletes. Below, we outline our response to their concerns.…”

The Effect of the Crow Hop on Elbow Stress During an Interval Throwing Program: Letter to the Editor

“…However, we are concerned that the methodology used may have led to false conclusions; that is, crow hop throws generated greater medial elbow torque than standing throws at distances up to 60 feet. 13 These authors also firmly stated that the crow hop throwing technique does not reduce medial elbow stress during a simulated throwing program, and it may actually increase torque at short throwing distances. 13 Research has shown that velocity is directly correlated to the rate of elbow injuries and ulnar collateral ligament reconstructions in Major League Baseball pitchers.…”

“…13 These authors also firmly stated that the crow hop throwing technique does not reduce medial elbow stress during a simulated throwing program, and it may actually increase torque at short throwing distances. 13 Research has shown that velocity is directly correlated to the rate of elbow injuries and ulnar collateral ligament reconstructions in Major League Baseball pitchers. 2,4,11,20 Biomechanical studies demonstrate that higher velocity pitches are highly correlated with increased shoulder and elbow torques.…”

“…The authors of the article ''The Effect of the Crow Hop on Elbow Stress During an Interval Throwing Program'' 13 should be applauded for their attempt to elucidate the elbow torques with and without a crow hop technique across the throwing distances of a typical interval throwing program. However, we are concerned that the methodology used may have led to false conclusions; that is, crow hop throws generated greater medial elbow torque than standing throws at distances up to 60 feet.…”

“…2,4,11,20 Biomechanical studies demonstrate that higher velocity pitches are highly correlated with increased shoulder and elbow torques. 8,9,10 This leads us to our first issue with the methodology by Lizzio and colleagues 13 when they did not standardize and control for the velocity between the 2 types of throwing techniques. The crow hop throws were thrown 3.2 mph faster at both 30 ft and 45 ft, 3.8 mph faster at 60 ft, and 2.6 mph faster at 90 ft when compared with the non crow hop throws; these were all noted as statistically significant differences.…”