Lower hamstring to quadriceps muscle strength ratio and lower body weight as factors associated with noncontact anterior cruciate ligament injury in male American football players: A prospective cohort study

Shuji Taketomi; Kohei Kawaguchi; Yuri Mizutani; Seira Takei; Ryota Yamagami; Kenichi Kono; Ryo Murakami; Tomofumi Kage; Takahiro Arakawa; Sayaka Fujiwara; Sakae Tanaka; Toru Ogata

doi:10.1016/j.asmart.2023.11.006

Lower hamstring to quadriceps muscle strength ratio and lower body weight as factors associated with noncontact anterior cruciate ligament injury in male American football players: A prospective cohort study

Asia Pac J Sports Med Arthrosc Rehabil Technol. 2023 Dec 15:35:43-47. doi: 10.1016/j.asmart.2023.11.006. eCollection 2024 Jan.

Authors

Shuji Taketomi^{1

2}, Kohei Kawaguchi^{1

2}, Yuri Mizutani², Seira Takei², Ryota Yamagami¹, Kenichi Kono¹, Ryo Murakami¹, Tomofumi Kage¹, Takahiro Arakawa¹, Sayaka Fujiwara^{2

3}, Sakae Tanaka¹, Toru Ogata^{2

3}

Affiliations

¹ Department of Orthopaedic Surgery Faculty of Medicine, The University of Tokyo, Japan.
² UTokyo Sports Science Initiative (UTSSI), Japan.
³ Department of Rehabilitation Medicine, The University of Tokyo, Japan.

Abstract

Background: Previous studies have aimed to determine the use of certain risk factors in predicting the occurrence of noncontact anterior cruciate ligament (ACL) injuries. Unfortunately, evidence regarding noncontact ACL injuries in male American football players is limited. This prospective cohort study aimed to identify intrinsic risk factors for noncontact ACL injury among male American football players.

Methods: This study evaluated 152 male American football players in Japan for potential noncontact ACL injury risk factors during a preseason medical assessment, including anthropometric, joint laxity, and flexibility, muscle flexibility, muscle strength, and balance measurements. A total of 25 variables were examined. Participants were monitored during each season for noncontact ACL injury, as diagnosed by physicians.

Results: Noncontact ACL injuries occurred in 11 knees of 11 players (prevalence; 7.1 %). Injured players were significantly more likely to have lightweight (P = 0.049). No statistically significant between-group differences were found for any other variables. Participants with a lower hamstring to quadriceps (H/Q) ratio (P = 0.04) were more likely to sustain noncontact ACL injuries.

Conclusion: Lower H/Q ratio and lower body weight were significantly associated with new-onset noncontact ACL injury in male American football players. These findings will help develop strategies to prevent noncontact ACL injuries in male American football players.

Keywords: Collegiate American football player; Hamstring to quadriceps muscle strength ratio; Injury prevention; Noncontact anterior cruciate ligament injury; Risk factor.