Initial kinematic chain injuries increase hazard of subsequent arm injuries in professional baseball pitchers

Garrett S Bullock; Charles A Thigpen; Thomas K Noonan; Michael J Kissenberth; Ellen Shanley

doi:10.1016/j.jse.2022.04.016

Initial kinematic chain injuries increase hazard of subsequent arm injuries in professional baseball pitchers

J Shoulder Elbow Surg. 2022 Sep;31(9):1773-1781. doi: 10.1016/j.jse.2022.04.016. Epub 2022 May 19.

Authors

Garrett S Bullock¹, Charles A Thigpen², Thomas K Noonan³, Michael J Kissenberth⁴, Ellen Shanley²

Affiliations

¹ Department of Orthopaedic Surgery, Wake Forest School of Medicine, Winston-Salem, NC, USA; Centre for Sport, Exercise and Osteoarthritis Research Versus Arthritis, University of Oxford, Oxford, UK. Electronic address: gbullock@wakehealth.edu.
² Department of Observational Clinical Research, ATI Physical Therapy, Greenville, SC, USA; University of South Carolina Center for Rehabilitation and Reconstruction Sciences, Greenville, SC, USA.
³ Department of Orthopaedic Surgery, University of Colorado School of Medicine, Denver, CO, USA; Steadman Hawkins Clinic, University of Colorado Health, Englewood, CO, USA.
⁴ Orthopaedic Surgery, Steadman Hawkins Clinic of the Carolinas, Greenville, SC, USA.

PMID: 35598837
DOI: 10.1016/j.jse.2022.04.016

Abstract

Background: Currently, there are few studies that have evaluated the relationship between a lower extremity or trunk injury (kinematic chain) and subsequent arm injury. The purpose of this study was (1) to investigate the relationship between initial kinematic chain (lower extremity or trunk) injury and subsequent arm injury; and (2) to investigate the relationship between initial shoulder or elbow injury and subsequent arm injury.

Methods: A 7-year prospective injury risk study was conducted with Minor League Baseball pitchers. Pitches, pitching appearances, athlete exposures (AEs), and arm injuries (≥1-day time loss) were documented throughout the season. Cox survival analyses with 95% confidence intervals (95% CIs) were performed. Confounders controlled for included age, body mass index, arm dominance, pitching role, previous arm injury, number of pitching appearances, and seasonal pitch load.

Results: A total of 297 pitchers participated (total player days = 85,270). Arm injury incidence was 11.4 arm injuries/10,000 AEs, and kinematic chain incidence was 5.2 injuries/10,000 AEs. Pitchers who sustained a kinematic chain injury demonstrated a greater hazard (2.6 [95% CI: 1.2, 5.6], P = .019) of sustaining an arm injury. Pitchers who sustained an initial shoulder injury demonstrated a greater hazard (9.3 [95% CI: 1.1, 83], P = .047) of sustaining a subsequent shoulder or elbow injury compared with pitchers who sustained an initial elbow injury.

Conclusions: Pitchers who sustained an initial lower extremity or trunk injury demonstrated an increased subsequent arm injury hazard compared with pitchers who did not. Pitchers who sustained an initial shoulder injury demonstrated a greater hazard of sustaining a subsequent arm injury compared with pitchers who sustained an initial elbow injury. However, this secondary analysis should be interpreted with caution. Clinicians should monitor risk with workload accumulation, which may be related to pitching compensatory strategies in a fatigued state. Pitchers who sustain a shoulder injury should be evaluated and perform both shoulder and elbow rehabilitation strategies before return to sport.

Keywords: Recurrent injury; elbow; frailty; lower extremity; shoulder; trunk.

MeSH terms

Arm Injuries* / epidemiology
Arm Injuries* / etiology
Baseball* / injuries
Biomechanical Phenomena
Elbow Injuries*
Humans
Prospective Studies
Shoulder Injuries* / epidemiology
Shoulder Injuries* / etiology