Comparison of Pitching from Flat Ground vs. 10-Inch Mound Regarding Elbow Varus Torque and Arm Speed.

Purpose: The purpose of this study was to examine the effect of throwing surface and distance on varus elbow torque and arm speed. Methods: 11 male collegiate baseball pitchers (age = 20.73 ± 1.56 years, height = 175.26 ± 9.03 cm, mass = 70.31 ± 9.03 kg) participated in this study. Varus elbow torque and distance were measured using a 3D motion sensor housed in a spandex sleeve at the medial joint line of the elbow. Subjects were instructed to complete their normal warmup routine as if they were about to pitch in a bullpen session or a game. Subjects were then fitted with the sleeve and 3D motion sensor and then instructed to throw 5 maximum effort fastballs at both 60 feet 6 inches and 50 feet 6 inches from a 10-inch mound and 5 maximum effort fastballs at both 60 feet 6 inches and 50 feet 6 inches from flat ground. A two-way analysis of variance with repeated measures was used to analyze the differences in elbow varus torque and arm speed when pitching from 60 feet 6 inches and 50 feet 6 inches from a 10-inch mound and from flat ground. Tests of significance were carried out at an alpha level p < 0.05. Results: Significant differences in elbow varus torque were found when throwing from a 10-inch mound compared to flat ground (10-inch mound = 46.99 ± 2.36, Flat ground = 42.67 ± 3.14). No significant differences in elbow varus torque were found when throwing from 60 feet 6 inches compared to 50 feet 6 inches regardless of surface (60 feet 6 inches = 45.38 ± 2.96, 50 feet 6 inches = 44.28 ± 2.59). No significant differences in arm speed were found regardless of surface or distance. Conclusions: Throwing from a 10-inch mound appears to place more torque on the elbow than throwing from flat ground. Clinicians should be mindful of this fact when progressing patients through throwing programs. [ABSTRACT FROM AUTHOR]