Purpose: The objective of this study was to explore the effects of training using wearable resistance (WR) applied above the elbow of the throwing arm on throwing velocity, arm speed, shoulder internal and external rotation, strength, and range of motion in baseball pitchers.
Methods: College baseball pitchers (N = 17) participated in a volume-matched 6-week throwing program, twice per week, unloaded (quasi-control) or with WR added to the upper arm (intervention). Arm speed was measured with an inertial sensor, throwing velocity via radar gun, shoulder rotator peak force (Fmax) with a strain gauge, and range of motion by a goniometer, before and after training. Linear mixed-effects models were used to examine differences between groups, time (pre and post), and their interaction with random intercepts for participants.
Results: A significant effect from pretesting to posttesting was observed in external-rotation range of motion (ηp2=.456, P = .005) and tended to increase more in the control group (interaction, ηp2=.261, P = .047). Otherwise, no other statistically significant differences were observed.
Conclusion: This was the first WR training study with pitchers, and the lack of clear improvement using upper-arm WR loading was notable. Future researchers should explore the efficacy of lower-arm loading and/or potentially increase training volume as a means of stimulating adaptation.
Keywords: loaded throwing; pitching; resistance training; shoulder strength; throwing velocity.