Author ORCID Identifier

https://orcid.org/0000-0001-5550-5661

Year of Publication

2021

Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation

College

Health Sciences

Department/School/Program

Rehabilitation Sciences

First Advisor

Dr. Timothy L. Uhl

Second Advisor

Dr. Terry R. Malone

Abstract

Identification of musculoskeletal (MSK) injury risk factors in baseball players can be challenging particularly for youth and high school coaches. Many baseball coaches lack a sports medicine and/or strength and conditioning staff to assist with injury prevention initiatives. Given the extensive responsibilities in managing the team and preparing the players for athletic competition, little time remains to focus on injury prevention and arm care programs. Furthermore, assessment, diagnosis, and management of MSK impairments is outside the scope of practice and expertise of baseball coaches. However, educating and empowering the coach to efficiently screen their players for potentially injury producing MSK impairments is more practicable. Therefore, the purpose of this dissertation was to develop a time efficient, feasible, field expedient screening tool which can be reliably administrated by the coach and identify important MSK risk factors common in baseball.

To mitigate overuse arm injuries, baseball coaches implement arm care programs to target MSK injury risk factors by improving strength, dynamic stability, and range of motion (ROM) of muscles and joints. Historically, arm care exercise programs consisted of generalized upper body strengthening or targeted stretching to a particular muscle group; however, current usage and understanding of arm care exercise programs among baseball coaches is lacking. A nation-wide survey of 654 high school baseball coaches revealed that 1) 87.3% (n=571/654) of coaches surveyed are using arm care programs, 2) only 18.6% (n=106/571) of these programs are individualized based on the specific needs of the player, 3) older coaches with more coaching experience are more likely to design individualized arm care programs, 4) lack of benefit (41%, n=34/83) and limited staffing (31.3%, n=26/83) were the greatest barriers to implementing arm care programs, and 5) coaches demonstrate inconsistent knowledge of MSK risk factors and injury prevention.

Most coaches (57.3%, n=375/654) surveyed take responsibility for playing the largest role in preventing baseball injuries, however, proper resources and knowledge of MSK risk factors limits their effectiveness. Empowering the coach with a screening tool which can be performed in less than three minutes and requires no equipment is a reasonable solution. The Arm Care Screen (ACS), modified from the principles of the Functional Movement Systems, includes three components scored as pass or fail to screen the rotational mobility of the shoulders, hips, and spine and dynamic balance. In a cohort of 31 baseball players, the ACS demonstrated substantial intra-rater reliability (k=0.76; 95% CI, 0.54-0.95) and excellent inter-rater reliability (k=0.89; 95% CI, 0.77-0.99) when performed by high school baseball coaches with minimal movement screening training.

Although movement screening is generally reliable, the discriminability of screening to discern MSK risk factors is unknown. In a cohort of 110 baseball players (youth, n=30, high school, n=50, and college, n=30), high sensitivity was observed on the reciprocal shoulder mobility (0.90; 95% CI, 0.82-0.95), 90/90 total body rotation (0.85; 95% CI, 0.77-0.91), and lower body diagonal reach (0.84; 95% CI, 0.76-0.90) screens of the ACS suggesting sufficient ability to identify MSK risk factors. The screen was able to discriminate between the impairment measures for all age levels except for thoracic spine rotation ROM. Shoulder, hip, and spine ROM and dynamic single leg balance measures were significantly lower in players who failed the corresponding ACS component except for shoulder and hip external rotation ROM.

The ACS is a feasible tool for baseball coaches to consider due to its simplistic scoring criteria, minimal staffing and equipment requirements, and its ability to detect MSK risk factors common in youth, high school, and college baseball players. Identification of MSK limitations is critical to addressing injury risk factors. Time efficient screening could allow coaches the opportunity to perform more frequent screenings and more closely monitor for development of risk factors throughout the season to potentially inform and thus refine arm care exercise programs.

Digital Object Identifier (DOI)

https://doi.org/10.13023/etd.2021.278

Funding Information

  1. Development of a Field Expedient Screening Tool for the Coach to Improve Musculoskeletal Impairments. Alumni Research and Scholarly Activity Fellowship. University of Evansville. Funded: $2,070.05. Investigator 2020.
  2. Understanding and Usage of Arm Care Programs and Injury Prevention Measures: A Survey of High School Baseball Coaches. Dissertation Funding through the Rehabilitation Sciences Department, Endowed University Professor in Health Sciences. University of Kentucky. Funded: $545.00. Investigator 2019.

Available for download on Friday, July 29, 2022

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