Association of prospective lower extremity musculoskeletal injury and musculoskeletal, balance, and physiological characteristics in Special Operations Forces

Karen A Keenan; Meleesa F Wohleber; Katherine A Perlsweig; Thomas M Baldwin; Michael Caviston; Mita Lovalekar; Christopher Connaboy; Bradley C Nindl; Kim Beals

doi:10.1016/j.jsams.2017.09.002

Association of prospective lower extremity musculoskeletal injury and musculoskeletal, balance, and physiological characteristics in Special Operations Forces

J Sci Med Sport. 2017 Nov:20 Suppl 4:S34-S39. doi: 10.1016/j.jsams.2017.09.002. Epub 2017 Sep 9.

Authors

Karen A Keenan¹, Meleesa F Wohleber², Katherine A Perlsweig², Thomas M Baldwin³, Michael Caviston⁴, Mita Lovalekar², Christopher Connaboy², Bradley C Nindl², Kim Beals²

Affiliations

¹ Neuromuscular Research Laboratory, Warrior Human Performance Research Centers, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, USA. Electronic address: kak170@pitt.edu.
² Neuromuscular Research Laboratory, Warrior Human Performance Research Centers, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, USA.
³ Naval Special Warfare Group 2, JEB Little Creek, USA.
⁴ Naval Special Warfare Center, USA.

PMID: 28958636
DOI: 10.1016/j.jsams.2017.09.002

Abstract

Objectives: Previous research has examined lower extremity (LE) musculoskeletal injury (MSI) patterns and risk factors in Special Operations Forces (SOF) trainees, conventional military personnel, and athletes; however, it is unclear if SOF have the same patterns/risk factors. This study aimed to determine the association of musculoskeletal, balance, and physiological characteristics with LE MSI in SOF.

Design: Cohort study.

Methods: A total of 726 Air Force (N=140), Navy Sea, Air, and Land (N=301), and Special Warfare Combatant Crewmen (N=285) SOF (age=25.72±4.77years, height=178.34±6.63cm, weight=84.28±9.03kg) participated in laboratory testing, including: LE muscular strength and flexibility; balance; body composition; anaerobic power/capacity; and aerobic capacity. Medical charts were reviewed for LE MSI 365days following laboratory testing. Participants were assigned by injury status and laboratory data stratified by tertile. Chi-square statistics were calculated to determine the frequency of LE MSI across tertiles for each characteristic.

Results: There was a significant association between LE MSI and: ankle inversion strength (weaker side: Χ(2)=17.703; stronger side: Χ(2)=18.911; p≤0.001); ankle eversion/inversion strength ratio (lower side: Χ(2)=13.456; higher side: Χ(2)=16.885; p≤0.001); hamstring flexibility (less flexible: Χ(2)=19.930; more flexible Χ(2)=15.185; p≤0.001); gastrocnemius-soleus flexibility (less flexible: Χ(2)=7.889, p=0.019); dynamic balance asymmetry (Χ(2)=7.444, p=0.024); Vestibular and Preference ratios (Χ(2)=9.124, p=0.010 and Χ(2)=6.572, p=0.037, respectively); and aerobic capacity (Χ(2)=13.935, p=0.001).

Conclusions: Characteristics associated with LE MSI are unique in SOF. Human performance program initiatives should include efforts to optimize ankle strength and flexibility, maintain moderate hamstring flexibility, expand dynamic balance strategies, and maximize aerobic capacity to reduce LE MSI risk.

Keywords: Association; Injuries; Lower extremity; Military; Special Operations Forces.

MeSH terms

Adult
Anaerobic Threshold / physiology
Ankle Joint / physiology
Body Composition
Chi-Square Distribution
Cohort Studies
Humans
Lower Extremity / injuries
Male
Military Personnel*
Muscle Strength / physiology*
Musculoskeletal System / injuries*
Occupational Injuries / etiology
Occupational Injuries / prevention & control*
Pliability / physiology*
Postural Balance / physiology*
Risk Factors
United States
Young Adult