Effects of an Injury Prevention Program on Anterior Cruciate Ligament Injury Risk Factors in Adolescent Females at Different Stages of Maturation

摘要

The ideal timing to implement anterior cruciate ligament injury prevention programs with respect to maturation is unclear. The purpose of this study was to investigate the effects of an injury prevention program on knee mechanics in early-, late-, and post-pubertal females. In the study, 178 adolescent female basketball players were assigned to six groups: early-pubertal training, early-pubertal control, late-pubertal training, and late-pubertal control, post-pubertal training, and post-pubertal control. The training groups performed an injury prevention program for six months. Medial knee displacement, knee flexion range of motion, and the probability of high knee abduction moment were assessed before and after the training period. After the six-month training period, medial knee displacement was significantly increased in the early-pubertal control group whereas it was unchanged in the early-pubertal training group. Knee flexion range of motion was significantly decreased in the early-pubertal control group whereas it did not change in the early-pubertal training group. The probability of high knee abduction moment was increased in the early-pubertal control group whereas it was unchanged in the earl-pubertal training group. The probability of high knee abduction moment was also decreased in the post-pubertal training group whereas it did not change in the post-pubertal control group. The program limited the development of high-risk movement patterns associated with maturation in early puberty while improving the knee mechanics in post-pubertal adolescents. Therefore, an injury prevention program should be initiated in early puberty and continue through the post-puberty years.Key points An ACL injury prevention program limited the development of high-risk movement patterns associated with maturation in early puberty while it improved the knee mechanics in post-pubertal adolescents.An improvement through a program might not be obvious due to the natural development of the faulty movement patterns in early-pubertal adolescents, while significant improvement through the training program can be expected in post-pubertal adolescents.An ACL injury prevention program should be initiated in early puberty and continue through the post-puberty years. Key words: Knee injuries, landing, neuromuscular control, pubertyIntroductionThe incidence of anterior cruciate ligament (ACL) injury significantly rises in females after the onset of puberty and peaks around 15-19 years-of-age (Renstrom et al., 2008). With an increasing enrollment in organized sports at younger ages, the incidence of ACL injuries is rising in children and adolescents (Werner et al., 2016). Injury to the ACL in children and adolescents is problematic, as studies have confirmed that ACL injury in youth will increase the risk of developing osteoarthritis (Caine and Golightly, 2011; Lohmander et al., 2007; Myklebust et al., 2003).Multiplanar loading, namely, knee abduction and internal tibial rotation, as well as anterior tibial translation accompanied by reduced knee flexion, are considered to be mechanisms of ACL injury (Quatman and Hewett, 2009; Shimokochi and Shultz, 2008). These biomechanical features are commonly observed during actual injury situations (Koga et al., 2010; Krosshaug et al., 2007; Olsen et al., 2004), and have been investigated in cadaveric studies (DeMorat et al., 2004; Kiapour et al., 2016; Levine et al., 2013; Oh et al., 2012). Prospective studies have identified increased knee valgus (Hewett et al., 2005) and decreased knee flexion (Leppanen et al., 2017) as biomechanical risk factors for ACL injuries which seem to develop during maturation in females (Ford et al., 2010; Hewett et al., 2004; 2015; Schmitz et al., 2009; Yu et al., 2005). Several studies have identified that females demonstrate heightened knee valgus motion following the onset of pubertal growth spurts compared to males (Ford et al., 2010; Hewett et al., 2004; 2015; Schmitz et al., 2009). In addition, females land with decreased knee flexion during a stop-jump task as they mature (Yu et al., 2005). These biomechanical changes might be because female adolescents do not demonstrate sufficient neuromuscular adaptation to rapid skeletal growth like their male counterparts (Hewett et al., 2004). Coinciding with the appearance of these biomechanical characteristics, ACL injury rates start to rise in females during puberty (Renstrom et al., 2008; Shea et al., 2004).To prevent this devastating injury, many prevention programs have been developed and are gradually being tested for their effectiveness. These programs can be effective in reducing the rate of ACL injuries according to a recent meta-analysis (Webster and Hewett, 2018). Furthermore, Myer et al. (2013) and Sugimoto et al. (2016) evaluated the effectiveness of the injury prevention programs for different age groups. They found that the programs were more effective in the mid-teen years (14-18 years) than in the l