Incidence of lower extremity injury in the National Football League:​ 2015 to 2018

Mack, Christina D.<sup>1</sup>; Kent, Richard W.<sup>2</sup>; Coughlin, Michael J.<sup>3,4</sup>; Shiue, Kristin Y.<sup>1</sup>; Weiss, Leigh J.<sup>5</sup>; Jastifer, James R.<sup>6,7</sup>; Wojtys, Edward M.<sup>8</sup>; Anderson, Robert B.<sup>9</sup>

Affiliations

¹IQVIA Real World Solutions, Research Triangle Park, North Carolina, USA.

²Center for Applied Biomechanics, University of Virginia, Biomechanics Consulting & Research (Biocore), Charlottesville, Virginia, USA

³University of California, San Francisco, San Francisco, California, USA

⁴Coughlin Foot and Ankle Clinic, Saint Alphonsus Hospital, Boise, Idaho, USA

⁵New York Football Giants, Quest Diagnostics Training Center, East Rutherford, New Jersey, USA

⁶Borgess Orthopedics, Kalamazoo, Michigan, USA

⁷WMU Homer Stryker M.D. School of Medicine, Kalamazoo, Michigan, USA

⁸MedSport, Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, Michigan, USA

⁹Bellin Health Titletown Sports Medicine and Orthopedics, Green Bay, Wisconsin, USA

Abstract and keywords

Background: Lower extremity injuries are the most common injuries in professional sports and carry a high burden to players and teams in the National Football League (NFL). Injury prevention strategies can be refined by a foundational understanding of the occurrence and effect of these injuries on NFL players.

Purpose: To determine the incidence of specific lower extremity injuries sustained by NFL players across 4 NFL seasons.

Study Design: Descriptive epidemiology study.

Methods: This retrospective, observational study included all time-loss lower extremity injuries that occurred during football-related activities during the 2015 through 2018 seasons. Injury data were collected prospectively through a leaguewide electronic health record (EHR) system and linked with NFL game statistics and player participation to calculate injury incidence per season and per 10,000 player-plays for lower extremity injuries overall and for specific injuries. Days lost due to injury were estimated through 2018 for injuries occurring in the 2015 to 2017 seasons.

Results: An average of 2006 time-loss lower extremity injuries were reported each season over this 4-year study, representing a 1-season risk of 41% for an NFL player. Incidence was stable from 2015 to 2018, with an estimated total missed time burden each NFL season of approximately 56,700 player-days lost. Most (58.7%) of these injuries occurred during games, with an overall higher rate of injuries observed in preseason compared with regular season (11.5 vs 9.4 injuries per 10,000 player-plays in games). The knee was the most commonly injured lower extremity region (29.3% of lower body injuries), followed by the ankle (22.4%), thigh (17.2%), and foot (9.1%). Hamstring strains were the most common lower extremity injury, followed by lateral ankle sprains, adductor strains, high ankle sprains, and medial collateral ligament tears.

Conclusion: Lower extremity injuries affect a high number of NFL players, and the incidence did not decrease over the 4 seasons studied. Prevention and rehabilitation protocols for these injuries should continue to be prioritized.

Keywords: lower extremity injury; injury prevention; injury epidemiology; sports injury; National Football League

Links

DOI: 10.1177/0363546520922547

PubMed: 32485114

WoS: 000537510800001

History

Received: 2019-01-01

Accepted: 2020-03-05

Cited Works (7)

Year	Entry
2019	Jastifer JR, McNitt AS, Mack CD, Kent RW, McCullough KA, Coughlin MJ, Anderson RB. Synthetic turf: history, design, maintenance, and athlete safety. Sports Health. January–February 2019;11(1):84-90.
2012	Hershman EB, Anderson R, Bergfeld JA, Bradley JP, Coughlin MJ, Johnson RJ, Spindler KP, Wojtys E, Powell JW. An analysis of specific lower extremity injury rates on grass and FieldTrf playing surfaces in National Football League games: 2000-2009 seasons. Am J Sports Med. October 2012;40(10):2200-2205.
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2019	Mack CD, Hershman EB, Anderson RB, Coughlin MJ, McNitt AS, Sendor RR, Kent RW. Higher rates of lower extremity injury on synthetic turf compared with natural turf among National Football League athletes: epidemiologic confirmation of a biomechanical hypothesis. Am J Sports Med. January 2019;47(1):189-196.
2017	Hunt KJ, Hurwit D, Robell K, Gatewood C, Botser IB, Matheson G. Incidence and epidemiology of foot and ankle injuries in elite collegiate athletes. Am J Sports Med. February 2017;45(2):426-433.
2015	Kent R, Forman JL, Lessley D, Crandall J. The mechanics of American football cleats on natural grass and infill-type artificial playing surfaces with loads relevant to elite athletes. Sports Biomech. 2015;14(2):246-257.

Cited By (2)

Year	Entry
2021	Kent R, Yoder J, O'Cain CM, Meade Spratley E, Arbogast KB, Sorochan J, McNitt A, Serensits T. Force-limiting and the mechanical response of natural turfgrass used in the National Football League: a step toward the elimination of differential lower limb injury risk on synthetic turf. J Biomech. October 11, 2021;127:110670.
2023	Hua Y. Body Composition and Bone Characteristics Data in NCAA D1 League Football Team by DXA and HRpQCT [Master's thesis]. University of Pittsburgh; 2023.