The Influence of Rate of Perceived Effort on Pitching Mechanics and Elbow Varus Torque in High School and Professional Pitchers.

Background: Previous evaluations in adult pitchers have noted discrepancies in pitchers' rate of perceived effort (RPE) versus actual effort when pitching. Purpose: To discern a relationship between RPE with objective measures of effort including ball velocity, maximal elbow varus torque, torque loading rate, and cumulative elbow varus torque in high school (HS) and professional (PRO) baseball pitchers. Study Design: Descriptive laboratory study. Methods: A total of 38 HS pitchers (age, 16.9 ± 0.9 years; height, 183.3 ± 6.0 cm; weight, 78.1 ± 9.2 kg) and 24 PRO pitchers (age, 24.0 ± 2.3 years; height, 188.8 ± 5.2 cm; weight, 90.9 ± 7.3 kg) were analyzed using 3-dimensional motion capture (480 Hz) while throwing fastballs. HS pitchers threw at 50%, 75%, and 100% effort; PRO pitchers threw at 75% and 100% effort. Elbow varus torque, loading rate, cumulative torque, and ball velocity were used to assess intra-pitcher relationships with a linear mixed-effects model. Results: HS pitchers significantly differed (P all < .001) at 50%, 75%, and 100% RPE for, respectively, ball velocity (30.2 ± 1.0 vs 32.2 ± 0.6 vs 35.1 ± 0.5 m/s), elbow varus torque (53.3 ± 4.4 vs 59.0 ± 3.3 vs 69.1 ± 2.8 N·m), cumulative torque (1919.0 ± 115.9 vs 2033.3 ± 85.5 vs 2339.2 ± 87.6 N·m*s), and torque loading rate (360.3 ± 53.3 vs 421.1 ± 38.6 vs 532.6 ± 53.1 N·m/s). Similar results were observed for PRO pitchers at 75% and 100% effort (P < .001). A strong correlation was found between the RPE and the measured torque parameters (all R 2 > 0.85). The observed change in measured variables did not correspond to the change in RPE for all metrics for both pitching populations (ie, HS at 50% effort threw at 86% ball velocity, 75% maximal elbow varus torque, 80% cumulative torque, and 67% torque loading rate). In PRO pitchers, variance did not differ between effort groups for all variables. In HS pitchers, there was greater variance in lower effort pitches for ball velocity between 50% and 100% (P < .001) and 50% and 75% (P < .001) and for torque loading rate for 75% to both 50% and 100% (P < .001). Conclusion: Although throws from HS and PRO pitchers at lower prescribed RPE showed lower observed effort, the reduction in observed efforts decreased disproportionately less compared with perceived efforts. PROs appear to be more adept at maintaining consistency during submaximal effort pitches compared with HS pitchers. Clinical Relevance: Interval throwing programs commonly rely on pitchers self-regulating intensity through RPE. Reductions in RPE do not consistently translate into proportional decreases in ball velocity or elbow varus torque, especially in HS pitchers who show greater variability at submaximal efforts. Simply asking pitchers to "throw easier" may not reliably reduce joint loading and could expose healing tissue to higher-than-intended stress. Clinicians should recognize the limitations of RPE-based workload progression, particularly in younger pitchers, and consider integrating objective monitoring tools (e.g., velocity tracking, wearable sensors, or biomechanical assessments) to ensure safer and more consistent return-to-throw rehabilitation.