Psychological traits regarding competitiveness are related to the incidence of anterior cruciate ligament injury in high school female athletes Masahiro Kosaka a , Junsuke Nakase a, ⁎, Hitoaki Numata a , Takeshi Oshima a , Yasushi Takata a , Shigenori Moriyama b , Takumi Oda b , Yosuke Shima c , Katsuhiko Kitaoka d , Hiroyuki Tsuchiya a a Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan b Division of Rehabilitation, Kanazawa University Hospital, Kanazawa, Japan c Department of Orthopaedic Surgery, KKR Hokuriku Hospital, Kanazawa, Japan d Department of Orthopaedic Surgery, Kijima Hospital, Kanazawa, Japan abstract article info Article history: Received 7 October 2015 Received in revised form 25 April 2016 Accepted 27 April 2016 Available online xxxx Background: The purpose of this study was to investigate the relationship between psychological competitive ability and the incidence of noncontact ACL injuries among high school female athletes. Methods: A three-year prospective cohort study was conducted using 300 15-year-old high school female ath- letes with no previous injuries or symptoms in their lower limbs (106 handball players and 194 basketball players). At baseline, their psychological competitive abilities were assessed using a self-administered questionnaire—the Diagnostic Inventory of Psychological Competitive Ability (DIPCA.3). After the baseline examination was performed at high school entry, all players were prospectively followed for 36 months to document any subsequent incidence of ACL injury, according to their coaches. An unpaired t-test with Welch's correction was performed to compare the differences in the psychological competitive abilities between the injured and uninjured players. Results: Of the 300 players, 25 (8.3%) experienced a noncontact ACL injury during the three-year observation period. The injured players had significantly higher total DIPCA.3 scores for psychological competitive ability than the uninjured players (169.9 ± 18.8 vs. 159.2 ± 21.6, P = .036). Additionally, the injured players had sig- nificantly higher scores than the uninjured players in the following categories: aggressiveness, volition for self- realization, volition for winning, judgment, and cooperation. However, no significant differences were observed in patience, self-control, ability to relax, concentration, confidence, decision, and predictive ability. Conclusions: High psychological competitive ability was associated with the incidence of noncontact ACL injuries in high school female athletes. Level of evidence: Level II (prospective cohort study). © 2016 Elsevier B.V. All rights reserved. Keywords: Anterior cruciate ligament Female athletes Injury Risk factor Psychological competitive ability 1. Introduction Although reconstruction surgery for anterior cruciate ligament (ACL) injuries has improved and shown stable results, many challenges still remain for this sports injury (e.g., it still requires a long recovery time and is associated with meniscal tears) [1,2]. In addition, an ACL injury is one of the most costly sports injuries [3,4]. A noncontact ACL injury is prevalent among high school female athletes, especially in those who play ball sports such as handball, basketball, soccer, and vol- leyball [5,6], and it is a very serious issue since it not only interferes with their sports activities but also puts them at risk for the early development of osteoarthritic changes in the future [7–9]. Therefore, the prevention of ACL injuries as well as an accurate diagnosis and proper treatment have significant importance in maintaining the future quality of life in these patients. Identifying and understanding the risk factors of this injury are essential for developing an effective prevention program, and many re- searchers have conducted studies that focus on multilateral aspects, such as anatomical, neuromuscular, hormonal, biomechanical, and en- vironmental factors [5,10–13]. However, psychological factors have been rarely reported on, and no consistent findings have been reported, although psychological factors along with strength and technical skills are known to have a significant influence on athletes [14,15]. In a com- petitive sport situation, the exertions of performance and also the inci- dence of injury can be influenced by psychological factors [16]. The Knee xxx (2016) xxx–xxx ⁎ Corresponding author at: Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-8641, Japan. Tel.: +81 76 265 2374; fax: +81 76 234 4261. E-mail address: nakase1007@yahoo.co.jp (J. Nakase). THEKNE-02274; No of Pages 5 http://dx.doi.org/10.1016/j.knee.2016.04.015 0968-0160/© 2016 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect The Knee Please cite this article as: Kosaka M, et al, Psychological traits regarding competitiveness are related to the incidence of anterior cruciate ligament injury in high school fe..., Knee (2016), http://dx.doi.org/10.1016/j.knee.2016.04.015