Pitch velocity is a predictor of medial elbow distraction forces in the uninjured high school-aged baseball pitcher

Abstract

Background: Medial elbow injuries are common among baseball pitchers. Easily accessed methods to assess medial elbow stress may be useful in identifying individuals with increased injury risk.

Hypothesis: Pitch velocity (PV) is positively associated with higher medial elbow adduction moments.

Study design: Cohort study; Level of evidence, 2.

Methods: Participants included 26 uninjured high school pitchers, 15 to 18 years in age. Three-dimensional data and PV were collected as athletes threw 10 fastballs for strikes to a regulation-distance target. Variables of interest were the normalized peak internal elbow adduction moment and peak PV. Linear regression was performed to evaluate the influence of PV on the adduction moment.

Results: For the group, mean PV was 71 mph (range, 58-81 mph), and the adduction moment was 0.558 Nm/Ht × mass (range, 0.378-0.723). PV was positively associated with the adduction moment (P < 0.01, R(2)= 0.373).

Conclusions: Talented young pitchers may be more susceptible to elbow injuries as a consequence of a biomechanical coupling between PV and upper extremity joint moments.

Clinical relevance: PV may be measured easily and serve as an indicator of medial elbow stress.

Figure 1.

Anterior view of marker placement and axis orientations for the upper extremity.

Figure 2.

The influence of the peak pitch velocity on the peak elbow adduction moment (P < 0.01, R = 0.373).