Previous Seasons Workload and Injury Among MLB Starting Pitchers
How many innings can we throw: does workload influence injury risk in Major League Baseball? An analysis of professional starting pitchers between 2010 and 2015. J Shoulder and Elbow Surgery. 27: 1386-1392, 2018.
Background: There has been increasing interest regarding the association between pitch counts, as well as total workload per season, and the risk of injury among Major League Baseball (MLB) starting pitchers.
Methods: Publicly available databases were used to identify all MLB starting pitchers who made at least 5 starts at the MLB level between 2010 and 2015. The following annual pitching statistics were collected for each starting pitcher:
- Number of starts
- Total season pitch counts
- Total season inning counts
- Average pitch count per game started
- Annual time on DL for any reason
- Annual time on DL related to upper extremity injury
- Annual time on DL related to lower extremity
- Annual time on DL related to axial body injury.
A multiple logistic regression program was used to analyze games started, pitch counts, innings pitched, and pitches per start during all previous seasons as a risk factor for injury in the current season, controlling for previous injury.
Results: A total of 161 starting MLB pitchers met the inclusion criteria. With the exception of total innings pitched from 2010-2011 being signiﬁcantly associated with DL placement in 2012 (no DL, 310.5 ± 97.5 innings; DL, 344.7 ± 85.9 innings; P = .040), no other ﬁnding for starts, pitch counts, innings, or pitches per start in the cumulative years from 2010-2014 had a signiﬁcant association with pitcher placement on the DL for any musculoskeletal reason or for an upper extremity reason between 2011 and 2015.
Conclusions: This study found:
- No association between preceding years of cumulative pitches and current DL status for any musculoskeletal reason
- No association between number of starts in preceding years and current DL status for any musculoskeletal reason
- No association between number of innings pitched in the preceding years and current DL status for any musculoskeletal reason
- No association between average number of pitches per start in the preceding years and current DL status for any musculoskeletal reason