Why are female basketball players increasingly at risk of lower-extremity injury? How should an injury prevention program for them be devised and implemented? The authors undertook a team study to find the answers.
By Major Kyle East, PT, DPT, DSC; Lieutenant Commander Lauren Brown, PT, DPT, DSC; and Colonel Donald Goss, PT, PHD
Knee injuries account for 10% to 25% of sports-related injuries.1 Athletes involved in jumping, pivoting, or cutting, such as in basketball, are at increased risk of serious knee injury, including tears of the anterior cruciate ligament (ACL).2 Female athletes are 2 to 8 times more likely to injure their ACL than male counterparts.1,3
More than 34,000 student–athletes play men’s and women’s collegiate basketball in the National Collegiate Athletic Association (NCAA).4 In women’s basketball, noncontact injuries constitute the highest percentage of severe injuries; of these, 63% occur during practice and 37%, during competition.4 The lower extremity was the site of the highest percentage of injuries in competitions (59%) and practices (67%). Additionally, the knee had the highest percentage of severe injuries.4
Research has shown that the largest percentage of injuries in women’s basketball, defined by specific anatomic region, occurred in the ankle (~ 22%), followed by the knee (18%).5 Most of the literature identifies the ankle as the most common site of injury 5-8; however, some authors report that the knee is the most affected region.5,9 Compared with men, women have a higher rate of injury related to overuse in practice, which is consistent with studies of injury in college athletes.10 A change in practice and conditioning programs might mitigate the impact of these injuries.10
A 2018 systematic review identified that peak knee–hip abduction moment was one of the most important predictors of ACL injury. 11 As ACL injuries are likely to occur within the first 40 milliseconds of the contact phase, technique training that reduces knee valgus motion and abduction loading during the early landing phase should be emphasized.12
Study population, design, and objectives
Consequent to a review of the best available literature and observing mounting evidence of more and more injuries to players on a local collegiate women’s basketball team, we devised an independent study to, first, assess why these athletes are increasingly at risk of lower-extremity injury and, second, implement an effective injury prevention program that is basketball-specific. Working with that team during the 2019 season, the objectives of this study were to:
- assess movement patterns
- identify functional musculoskeletal deficits
- implement an evidence-based program to prevent knee injury.
At the time of the study, the 16 women who had been on the team roster since the beginning of the season had a significant history of injury (Table 1). In all, of the 16 players on the roster, 9 (56%) sustained injury, including 3 (19%) whose injury was season-ending (2 with a ruptured ACL, 1 with a meniscal tear).
Twelve players on the team verbally consented to undergo video analysis during 4 predetermined tests. Each was video-recorded at 240 Hz/sec, utilizing the Hudl technique (Hudl, Lincoln, NE). For each player, tests were performed twice; recordings were made in frontal and sagittal planes. Assessment drills were designed to assess trunk control, knee moments, and landing techniques during basketball-specific activities—representing movements performed in practice and games.
Two reviewers (coauthors KE and LB) analyzed each player in both planes for aberrant movement. A third reviewer was utilized if there was disagreement in scoring a player during a specific test. For each of the 4 assessments, 3 criteria were judged (12 criteria in total) (Table 2). A score of 0 for any given criterion correlated with “no deficit.” A score of 1 was considered an “aberrant movement” (ie, knee valgus at take-off, leg stiffness upon landing, trunk lean). Composite scores for each player were grouped into 3 ranges:
Players who scored in the range of 0-4 (GREEN) were considered to require less neuromuscular training and had a decreased risk of noncontact lower-extremity injury while playing basketball.
Players in the range of 5-8 (YELLOW) were still considered at decreased risk of injury but were observed to have multiple aberrant movements on different drills. They were identified as potentially benefiting from additional neuromuscular training.
Players in the range of 9-12 (RED) were considered at high risk of injury. They required one-on-one training from either an athletic trainer or strength and conditioning coach to improve hip strength, landing mechanics, and neuromuscular control of the lower extremity and trunk.
To assess movement during dynamic activities, the reviewers included a sport-specific movement screening assessment. The reviewers took into consideration several tests and did not categorize the athletes on 1 aberrant movement only. Of the 12 players screened, 5 were scored in the GREEN range, requiring only minor correction of landing or jumping. It was determined that a basketball-specific prevention program implemented before practice would be sufficient to decrease their risk of injury.
The other 7 players scored in the YELLOW range; however, 3 of them were subcategorized as “at high risk” (RED range) after submitting to a subjective “eye test,” which is often utilized in sports to assess the athlete overall. It was determined that 6 YELLOW range players required additional strength and proprioceptive training in the off-season. Of those 6, the 3 players considered at high (RED) risk required, in addition, one-on-one attention and training from the certified team athletic trainer during the season. For them, the program will likely include additional strengthening exercises, dynamic proprioceptive drills, and additional video analysis with real-time feedback, as well as off-season training.
Implementation and Intervention
An ACL prevention program should incorporate feedback to the athlete regarding her landing technique and provide opportunities for her to correct that technique while practicing proper mechanics.13 This effort at correction can involve having a partner athlete or team athletic trainer provide the feedback, or can include the use of mirrors and video recording so that she can observe good and bad form.13,14 The intervention for this collegiate women’s basketball team was designed to mimic movements that occur in basketball and to challenge the players in various game-like situations (Figure).
The most common playing scenarios predictive of a noncontact ACL injury include:
- change of direction or cutting maneuvers, combined with deceleration
- landing from a jump in, or near, full extension
- pivoting with the knee near full extension and a planted foot.1,15
With those precipitating scenarios in mind, the choice of exercises developed for the study program include strength training, plyometrics, and proprioceptive drills. Research indicates that plyometrics should include cutting, jumping, and lateral movements, followed by the addition of “perturbation,” or disturbances, to determine whether proper form is maintained as the athlete is challenged and the situation begins to resemble a real-time sports situation.13
In addition, the certified athletic trainer and team were advised to implement the exercises at the beginning of practice to maximize neuromuscular gains. The rationale behind this method of delivery of the program is to increase compliance: Warmups are consistently utilized in sports, preparing the athlete neuromuscularly for training in a nonfatigued state.16 When exercises are performed in a fatigued state, or with poor or inconsistent biomechanical technique, an aberrant pathokinematic motor pattern might be reinforced, neuromuscularly.16,17
After reviewing changes to the current team warmup, KE, LB, and additional university faculty had the athletes perform the new injury prevention program warm-up 1 exercise at a time. The warm-up was conducted in this manner to ensure that each player was able to perform the exercise correctly and feel confident in their movement; doing so also permitted the staff to better assess each athlete and uncover additional movement deficits and identify athletes who might need to be placed in the RED range of scores.
As the 2019-2020 season gets underway, the current women’s basketball team certified athletic trainer (ATC) updated the authors on the implementation of the ACL prevention program and current injuries among the athletes. The team currently participates in the prevention program twice a week since returning from military field summer training. The intervention program is now incorporated as part of their strength and conditioning lifting program. There have been no injuries during basketball-related training. However, the women’s basketball team has had one player with an ACL injury that occurred secondary to contact during military- related training. The ATC in conjunction with the strength and conditioning coach plan to continue the ACL prevention program throughout the remainder of the season.
The identified prevalence of deficits was unexpectedly high. This study provided an excellent opportunity to work with collegiate-level athletes. Because this basketball team is associated with a top-tier university (academically and athletically), we expected to see few biomechanical deficits among these athletes. However, with the exception of a few players, most had marked knee valgus with jumping, increased leg stiffness during landing, and poor neuromuscular control when challenged with external perturbations.
Close, individualized analysis is essential for obtaining good outcomes. We established that it was important to analyze each player in real-time activities and to scrutinize their movements on video recordings. In addition, using several spotters to identify aberrant movements allowed the staff to cast a larger net—the goal being to identify players at risk of injury and, ideally, prevent further injury and therefore time off the court.
Strength and conditioning injury prevention programs should be gender-specific. We came to the realization that current warm-up and strengthening programs implemented for these women athletes are not appropriate. It was incorrectly assumed that strength and conditioning coaches were employing a prevention program that was 1) designed specifically for female athletes and 2) sport-specific; however, these key aspects of injury prevention were missing from prevention programs. For the future, it is imperative that physical therapists responsible for athletic and military teams take the time to analyze and evaluate their strengthening and conditioning programs to ensure that they align with the goals of the team and are sport- or mission-specific.
Considerations for the Future
The lower-extremity injury prevention program that we developed for the study basketball team was implemented midseason; this is one limitation of the study. To maximize the benefit of injury prevention in athletes, such a program should begin preseason, and be conducted 3 or 4 times a week.13
Ideally, at Week 6 and Week 12, the medical staff should re-record the athletes, analyze their performance, and re-score them, utilizing the original 4 assessments and their corresponding criteria. The assessments should be performed to see whether, objectively, the players are making the appropriate neuromuscular and proprioceptive changes. For players whose assessment score is not in the GREEN range, additional resources and time should be provided to prevent lower-extremity injury.
Last, it would be prudent to refine the assessments and interventions so that their utility and impact can be expanded to other female athletic teams, including soccer, volleyball, handball, and rugby.
Major Kyle East, PT, DPT, DSC, 23d Special Tactics Squadron, Hurlburt Field, FL, US; Lieutenant Commander Lauren Brown, PT, DPT, DSc, Naval Hospital, Camp Pendleton, CA, US; and Colonel Donald Goss, PT, PhD, Womack Army Medical Center, Fort Bragg, NC, US
Disclosure: The authors declare no conflicts of interest. Any reference to a specific commercial product, process or service by trade name, trademark, manufacturer, or otherwise, does not constitute or imply its endorsement, recommendation or favoring by the United States Government.
The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of Defense, the United States Army/Air Force or the United States Military Academy at West Point.
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