Pilot study of female high school basketball players' anterior cruciate ligament injury knowledge, attitudes, and practices

An anterior cruciate ligament (ACL) injury prevention program was evaluated. One hundred and thirteen female high school varsity and junior varsity basketball players and 12 coaches participated in an 8-week educational and skills program. Demographic and injury history data were collected. At pre-intervention and at the end of season, knowledge, attitudes, and practices about ACL risk and injury prevention were assessed via questionnaires, and frequency of two-footed landings were videotaped during games. Univariate statistics described the sample. Paired t -tests evaluated the program's impact. Cronbach's α, correlations, and κ statistics assessed the validity and reliability of questionnaires and video analysis. Of the 113 players, 74 completed the study. The players' mean age was 16.25 years (SD=1.07; range=14.2–18.8). Baseline knowledge score was 57.2%, practice 58.4%, and attitude 73.5%. The mean baseline knowledge score of the 12 coaches (mean age=40.8 years; SD=10.3; range=26.9–56.3) was 68.7%. Players' knowledge about ACL injury prevention improved ( t =2.57; P <0.01). No changes in attitudes toward injury prevention were found ( t _diff=1.88; P <0.06). Inter-rater reliability of two-footed landings observed was acceptable (κ=0.72). Videotape analyses revealed a 5.5% increase in landing performance ( t _diff=9.6; P <0.0001). The program increased knowledge about ACL injury risk and improved player's landing skills.     

Epidemiological survey of anterior cruciate ligament injury in Japanese junior high school and high school athletes: cross-sectional study

We investigated the incidence of anterior cruciate ligament (ACL) injuries among athletes in junior high school and high school by retrospectively reviewing Japan Sports Council notification data registered over a period of 10 years. The total number of ACL injuries during the 10-year period was 30,458, with an incidence of 0.81 per 1000 athlete-years. Among those with ACL injuries, the ratio of girls to boys was 2.8, and incidence of injury was significantly greater among girls than boys (1.36 as against 0.48). Athletes in the 11th grade demonstrated the highest incidence of ACL injuries. We also found that the greatest incidence of ACL injuries was among female high school basketball players; the second highest being among female high school Judo athletes. For sports with a greater number of ACL injuries and a higher injury rate, it is necessary to obtain more detailed data and analysis to determine an effective prevention programme.     

A survey of injuries to the anterior cruciate ligament of the knee in female basketball players

This study surveyed 76 female basketball-related injuries that occurred during a 30-month period at the B.C. Sports Medicine Clinic. The knee was the most common site of injury (72%), and anterior cruciate ligament (ACL) rupture accounted for 25% of all basketball injuries seen. A total of 19 ACL ruptures in females were seen as compared to only 4 ACL ruptures in male basketball players during the same time period. During this time period a total of 151 males and 76 female basketball players were seen. Each patient was assessed as to age, height, weight, and alignment and questioned as to mechanism of injury, playing position, experience, and training plus previous injuries. Possible etiological factors postulated included player position, joint laxity, weak quadriceps mechanism, and a possible hormonal basis.     

Isokinetic muscle performance in healthy female handball players and players with a unilateral anterior cruciate ligament reconstruction

A total of 114 healthy female European team handball players in the elite to second division with no previous ACL injury, and the uninjured legs of 22 females with a unilaterally reconstructed ACL (the injury sustained while playing handball; mean time from reconstruction 15 months) were examined with a Biodex isokinetic testing device. Five extensions and flexions at lower speed (60°/s) and 15 repetitions at higher speed (240°/s) were performed. Gravity-corrected peak torque values for flexion and extension were obtained, and hamstrings-to-quadriceps ratios (H/Q) were calculated at both speeds. Compared with the control group, the uninjured legs of the injury group showed 8% weaker quadriceps muscles and 14% higher H/Q ratios at higher speed. The other between-group comparisons were not significant. These differences could have been developed by strength reduction after the injury in the noninjured limb due-to-insufficient rehabilitation, by a weaker musculature in the patient group already initially, or by both mechanisms. If the second option is true, the finding may indicate that weak quadriceps musculature is one of the risk factors for anterior cruciate ligament injuries. The study establishes additional normative data on hamstrings and quadriceps torque on high-level female handball players.     

Comparing the incidence of anterior cruciate ligament injury in collegiate lacrosse, soccer, and basketball players: implications for anterior cruciate ligament mechanism and prevention

BACKGROUND: Female college basketball and soccer athletes have higher rates of anterior cruciate ligament injury than do their male counterparts. Rates of anterior cruciate ligament injuries for women and men in collegiate lacrosse have not been examined. Understanding anterior cruciate ligament injury patterns in lacrosse, a full-contact sport for men and noncontact sport for women, could further injury prevention efforts. HYPOTHESES: Female anterior cruciate ligament injury rates will decrease over time owing to longer participation in sports. Lacrosse anterior cruciate ligament injury rates will be lower than rates in basketball and soccer possibly owing to beneficial biomechanics of carrying a lacrosse stick. STUDY DESIGN: Cohort study (Prevalence); Level of evidence, 2. METHODS: Data from the National Collegiate Athletic Association Injury Surveillance System were analyzed to compare men's and women's anterior cruciate ligament injuries in basketball, lacrosse, and soccer over 15 years. RESULTS: Anterior cruciate ligament injury rates in women's basketball and soccer were 0.28 and 0.32 injuries per 1000 athlete exposures, respectively, and did not decline over the study period. In men's basketball, injury rate fluctuated between 0.03 and 0.13 athlete exposures. Rates of anterior cruciate ligament injury did not significantly change in men's soccer over the study period. The rate of anterior cruciate ligament injury in men's lacrosse (0.17 athlete exposures, P < .05) was significantly higher than in men's basketball (0.08 athlete exposures) and soccer (0.12 athlete exposures). Injury rate in women's lacrosse (0.18 athlete exposures, P < .05) was significantly lower than in women's basketball and soccer. CONCLUSION: There was no discernable change in rate of anterior cruciate ligament injury in men or women during the study period. Men's lacrosse is a high-risk sport for anterior cruciate ligament injury. Unlike basketball and soccer, the rates of anterior cruciate ligament injury are essentially the same in men's and women's lacrosse. The level of allowed contact in pivoting sports may be a factor in determining sport-specific anterior cruciate ligament risk.     

Effects of an anterior cruciate ligament injury prevention program on performance in adolescent female soccer players

Female soccer players are three times more likely to suffer a non‐contact anterior cruciate ligament (ACL) tear compared with male soccer players. Several ACL injury prevention programs have been developed and are used to reduce injury risk. However, to date there is limited information on how such programs affect physical performance. The aim of this randomized controlled study was to investigate the effects of the Prevent Injury Enhance Performance (PEP) program in adolescent female soccer players. Four soccer teams were randomly assigned to an intervention (PEP) or control (CON) group and assessed at baseline, 6 weeks, and 12 weeks on linear sprinting, countermovement jump (CMJ), and two agility tests. A mixed model factorial ANOVA with repeated measures was used to assess for treatment effects on the dependent variables. Improvements in 27.3 and 36.6 m sprint times (<0.10 s) were evident during the first 6 weeks for PEP, but reverted back to baseline values by 12 weeks; there were no changes for 9.1 or 18.2 m sprint times in either group. There was no change in the CMJ height for PEP; however, there was a decrement at 6 and 12 weeks compared with baseline in CON. Performance on the Illinois and pro‐agility tests declined in both groups. Our findings demonstrate that improvements in linear sprint performance were small and transient in adolescent female soccer players, and that there was no benefit of the PEP program on CMJ or agility performance. ACL injury prevention programs designed as a structured warm‐up routine seem to lack the necessary stimulus to enhance athletic performance.     

Prevention of anterior cruciate ligament injury in the female athlete

The relationships of gender, age and training to the incidence of anterior cruciate ligament (ACL) injury are pivotal to developing a comprehensive neuromuscular and proprioceptive training programme to decrease ACL injuries in female athletes. A prophylactic neuromuscular and proprioceptive training programme may have direct benefit in decreasing the number of ACL injuries in female athletes. This research foundation endorses further epidemiological and biomechanical studies to determine the exact mechanism of ACL injury and the most effective intervention for decreasing ACL injuries in this high-risk population.     

Risk factors for noncontact ankle sprains in high school football players: the role of previous ankle sprains and body mass index

BACKGROUND: In a previous study, we noted a possible connection between an athlete's weight and risk of ankle sprain. HYPOTHESIS: A high body mass index and a history of a previous ankle sprain increase the risk of a subsequent noncontact sprain. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: One hundred fifty-two athletes from 4 football teams were observed (2 varsity and 2 junior varsity). Two teams were observed for 3 seasons, and 2 teams were observed for 1 season. Before each season, body mass, height, history of previous ankle sprains, and ankle tape or brace use were recorded. RESULTS: There were 24 ankle sprains, of which 15 were noncontact inversion sprains (11 grade I, 3 grade II, 1 grade III; incidence, 1.08 per 1000 athlete-exposures). Injury incidence was higher in athletes with previous ankle injuries (2.60 vs 0.39; P < .001). Body mass index was also a risk factor (P < .05): injury incidence was 0.52 for players with a normal body mass index, 1.05 for players at risk of overweight, and 2.03 for overweight players. Injury incidence was 0.22 for normal-weight players with no previous ankle sprain compared with 4.27 for overweight players who had a previous sprain. CONCLUSION: An overweight player who had a previous ankle sprain was 19 times more likely to sustain a noncontact ankle sprain than was a normal-weight player with no previous ankle sprain. CLINICAL RELEVANCE: Ankle sprain prevention strategies should be targeted at football players with a high body mass index and a history of previous ankle sprains.     

Valgus knee motion during landing in high school female and male basketball players

PURPOSE: The purpose of this study was to utilize three-dimensional kinematic (motion) analysis to determine whether gender differences existed in knee valgus kinematics in high school basketball athletes when performing a landing maneuver. The hypothesis of this study was that female athletes would demonstrate greater valgus knee motion (ligament dominance) and greater side-to-side (leg dominance) differences in valgus knee angle at landing. These differences in valgus knee motion may be indicative of decreased dynamic knee joint control in female athletes. METHODS: Eighty-one high school basketball players, 47 female and 34 male, volunteered to participate in this study. Valgus knee motion and varus-valgus angles during a drop vertical jump (DVJ) were calculated for each subject. The DVJ maneuver consisted of dropping off of a box, landing and immediately performing a maximum vertical jump. The first landing phase was used for the analysis. RESULTS: Female athletes landed with greater total valgus knee motion and a greater maximum valgus knee angle than male athletes. Female athletes had significant differences between their dominant and nondominant side in maximum valgus knee angle. CONCLUSION: The absence of dynamic knee joint stability may be responsible for increased rates of knee injury in females but is not normally measured in athletes before participation. No method for accurate and practical screening and identification of athletes at increased risk of ACL injury is currently available to target those individuals that would benefit from neuromuscular training before sports participation. Prevention of female ACL injury from five times to equal the rate of males would allow tens of thousands of young females to avoid the potentially devastating effects of ACL injury on their athletic careers.     

Lower preseason reactive strength index scores are associated with injury in female collegiate volleyball players but not male collegiate basketball players

ObjectivesFunctional tests are used by sports medicine professionals to discriminate injury risk in athletes. One test that has shown promise is the drop vertical jump (DVJ); however, it is primarily used to evaluate measures associated with anterior cruciate ligament injury. The DVJ test can also be used to calculate the reactive strength index (RSI); a measure used to assess an athlete’s power. The ability of the RSI to discriminate injury risk is unknown. The purpose of this study was to prospectively evaluate the ability of preseason RSI scores to identify athletes at risk for a noncontact time-loss injury to the low back or lower extremities.DesignProspective cohort.MethodsOne hundred and fifty-five male collegiate basketball (BB) players and 117 female collegiate volleyball (VB) players were recruited for this study. DVJ tests were performed in a motion capture lab.ResultsFemale VB players with a RSI 0.9125 m/s or less (30.48 cm box) were 4 times (relative risk = 4.2 [95% CI: 1.0, 17.7]; p-value = 0.024) more likely to be injured. There was no association between preseason scores and injury in the male BB athletes.ConclusionRSI scores should be collected for female collegiate VB players as part of a preseason screen.     

Two-dimensional motion analysis of dynamic knee valgus identifies female high school athletes at risk of non-contact anterior cruciate ligament injury

Purpose

Female athletes are at greater risk of non-contact ACL injury. Three-dimensional kinematic analyses have shown that at-risk female athletes have a greater knee valgus angle during drop jumping. The purpose of this study was to evaluate the relationship between knee valgus angle and non-contact ACL injury in young female athletes using coronal-plane two-dimensional (2D) kinematic analyses of single-leg landing.

Methods

Two hundred ninety-one female high school athletes newly enrolled in basketball and handball clubs were assessed. Dynamic knee valgus was analysed during single-leg drop jumps using 2D coronal images at hallux–ground contact and at maximal knee valgus. All subjects were followed up for 3 years for ACL injury. Twenty-eight (9.6%) of 291 athletes had ACL rupture, including 27 non-contact ACL injuries. The injured group of 27 knees with non-contact ACL injury was compared with a control group of 27 randomly selected uninjured knees. The relationship between initial 2D movement analysis results and subsequent ACL injury was investigated.

Results

Dynamic knee valgus was significantly greater in the injured group compared to the control group at hallux–ground contact (2.1 ± 2.4 vs. 0.4 ± 2.2 cm, P = 0.006) and at maximal knee valgus (8.3 ± 4.3 vs. 5.1 ± 4.1 cm, P = 0.007).

Conclusion

The results of this study confirm that dynamic knee valgus is a potential risk factor for non-contact ACL injury in female high school athletes. Fully understanding the risk factors that increase dynamic knee valgus will help in designing more appropriate training and interventional strategies to prevent injuries in at-risk athletes.

Level of evidence

Prognostic studies, Level II.

     

Mechanisms of anterior cruciate ligament injury in basketball: video analysis of 39 cases

BACKGROUND: The mechanisms of anterior cruciate ligament injury in basketball are not well defined. PURPOSE: To describe the mechanisms of anterior cruciate ligament injury in basketball based on videos of injury situations. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Six international experts performed visual inspection analyses of 39 videos (17 male and 22 female players) of anterior cruciate ligament injury situations from high school, college, and professional basketball games. Two predefined time points were analyzed: initial ground contact and 50 milliseconds later. The analysts were asked to assess the playing situation, player behavior, and joint kinematics. RESULTS: There was contact at the assumed time of injury in 11 of the 39 cases (5 male and 6 female players). Four of these cases were direct blows to the knee, all in men. Eleven of the 22 female cases were collisions, or the player was pushed by an opponent before the time of injury. The estimated time of injury, based on the group median, ranged from 17 to 50 milliseconds after initial ground contact. The mean knee flexion angle was higher in female than in male players, both at initial contact (15 degrees vs 9 degrees , P = .034) and at 50 milliseconds later (27 degrees vs 19 degrees , P = .042). Valgus knee collapse occurred more frequently in female players than in male players (relative risk, 5.3; P = .002). CONCLUSION: Female players landed with significantly more knee and hip flexion and had a 5.3 times higher relative risk of sustaining a valgus collapse than did male players. Movement patterns were frequently perturbed by opponents. CLINICAL RELEVANCE: Preventive programs to enhance knee control should focus on avoiding valgus motion and include distractions resembling those seen in match situations.     

Weak associations between body mass index and self-reported disability in people with unilateral anterior cruciate ligament reconstruction

Purpose and hypothesis

Individuals with an anterior cruciate ligament reconstruction (ACLR) are susceptible to persistent disability, weight gain and the development of knee osteoarthritis. It remains unclear whether body mass index (BMI) is a factor that influences disability following ACLR. The purpose of this study was to determine the association between BMI and self-reported disability [International Knee Documentation Committee (IKDC) Index] in individuals with a unilateral ACLR. We hypothesized that lower BMI would associate with higher IKDC.

Methods

BMI and IKDC were measured in 668 individuals with a unilateral ACLR (60.9% female, BMI 24.4 ± 3.7 kg/m², IKDC 84.7 ± 11.9%). Bivariate associations were conducted between BMI and IKDC for the entire sample and selected subsets (gender, ACLR graft type and history of meniscal injury). Multiple regression analyses were used to determine the impact of potential covariates (Tegner score, age and months since ACLR) for significant bivariate associations. After accounting for covariates, there were no significant associations between BMI and IKDC when separately evaluating the cohort based on either gender or history of a concomitant meniscal injury. The odds of achieving age- and gender-matched healthy population average IKDC scores for those with low (<25) and high (≥25) BMI were determined.

Results

Lower BMI associated with higher IKDC (r = ?0.08, P = 0.04). For the entire sample, BMI did not uniquely predict variance in IKDC (ΔR ² > 0.001, n.s.) after accounting for covariates. BMI uniquely predicted a significant but negligible amount of variance in IKDC in individuals with a patellar tendon autograft (ΔR ² = 0.015, n.s.). Individuals with low BMI demonstrated higher odds (odds ratio = 1.45; 1.05–1.99) of achieving population average IKDC scores compared to participants with high BMI.

Conclusions

There was a significant but negligible correlation between lower BMI and lesser disability in individuals with unilateral ACLR and individuals who are underweight or of normal BMI demonstrated higher odds of achieving population average IKDC scores compared to overweight or obese individuals. While an overall association was found between lower BMI and lesser disability, the magnitude of the association remains negligible; therefore, BMI was not a strong clinical predictor of successful ACLR outcomes in this cohort of patients with unilateral ACLR.

Level of evidence

Cross-sectional prognostic study, Level II.

     

Factors associated with playing football after anterior cruciate ligament reconstruction in female football players

This study investigated whether player‐related factors (demographic, personality, or psychological factors) or the characteristics of the anterior cruciate ligament (ACL) injury were associated with the return to playing football in females after ACL reconstruction (ACLR). We also compared current knee function, knee related quality of life and readiness to return to sport between females who returned to football and those who had not returned. Females who sustained a primary ACL rupture while playing football and underwent ACLR 6–36 months ago were eligible. Of the 460 contacted, 274 (60%) completed a battery of questionnaires, and 182 were included a median of 18 months (IQR 13) after ACLR. Of these, 94 (52%) returned to football and were currently playing, and 88 (48%) had not returned. Multiple logistic regression analysis identified two factors associated with returning to football: short time between injury and ACLR (0–3 months, OR 5.6; 3–12 months OR 4.7 vs reference group > 12 months) and high motivation. Current players showed higher ratings for current knee function, knee‐related quality of life, and psychological readiness to return to sport (P < 0.001). Undergoing ACLR sooner after injury and high motivation to return to sports may impact a player's return to football after ACLR.     

Evaluation of hamstring muscle strength and morphology after anterior cruciate ligament reconstruction

This study aimed to clarify the relationship between knee flexor strength and hamstring muscle morphology after anterior cruciate ligament (ACL) reconstruction using the semitendinosus (ST) tendon and to determine the causative factors of decreased knee flexor muscle strength. Fourteen male and ten female patients who resumed sports activities after surgery participated in the experiment. Isometric knee flexion torque was measured at 30°, 45°, 60°, 90°, and 105° of knee flexion. Magnetic resonance imaging (MRI) was used to calculate ST muscle length and hamstring muscle volume, and to confirm the status of ST tendon regeneration. The correlation between the MRI findings and flexor strength was analyzed. Regenerated ST tendon was confirmed in 21 of the 24 patients, but muscle volume (87.6%) and muscle length (74.5%) of the ST in the operated limb were significantly smaller than those in the normal limb. The percentage of the knee flexion torque of the operated limb compared with that of the normal was apparently lower at 105° (69.1%) and 90° (68.6%) than at 60° (84.4%). Tendon regeneration, ST muscle shortening, and ST muscle atrophy correlated with decreased knee flexion torque. These results indicated that preserving the morphology of the ST muscle‐tendon complex is important.     

Factors associated with anterior cruciate ligament injury: history in female athletes

AIM: Little is known about the association of lower extremity structural malalignments, flexibility patterns, generalized laxity, postural control, previous ankle sprain history and the increased risk of anterior cruciate ligament (ACL) injuries in females. We hypothesized that females with a history of ACL injury would be more likely to have a history of prior ankle sprain and different structural alignments than females without a history of ACL injury. METHODS: It is a case control study: 33 young adult females with a history of an ACL injury and 33 controls with no history of knee injury provided their knee and ankle injury history and had 16 lower extremity measures taken. RESULTS: The factors most associated with ACL injury history were greater generalized laxity (r(2) change: 0.073), greater genu recurvatum (r(2) change: 0.069), and decreased iliotibial band (ITB) flexibility (r(2) change: 0.069). There was also a significant association between ACL injury history and previous ankle sprain injury history (chi squared=5.27; P=0.02). Those with a history of ACL injury were more likely to have had a prior ipsilateral ankle sprain. CONCLUSION: Increased generalized laxity, greater genu recurvatum, and decreased ITB flexibility discriminated between females with and without history of ACL injury. A relationship linking previous ankle injury and ACL injury risk was found. Taking a thorough medical history and screening for generalized laxity, genu recurvatum, and a tight ITB in those with a history of LAS, may help identify those at risk for an ACL injury and who may benefit most from preventive measures.     

Kinematics and electromyography of landing preparation in vertical stop-jump: risks for noncontact anterior cruciate ligament injury

BACKGROUND: Biomechanical analysis of stop-jump tasks has demonstrated gender differences during landing and a potential increase in risk of noncontact anterior cruciate ligament injury for female athletes. Analysis of landing preparation could advance our understanding of neuromuscular control in movement patterns and be applied to the development of prevention strategies for noncontact anterior cruciate ligament injury. HYPOTHESIS: There are differences in the lower extremity joint angles and electromyography of male and female recreational athletes during the landing preparation of a stop-jump task. STUDY DESIGN: Controlled laboratory study. METHODS: Three-dimensional videographic and electromyographic data were collected for 36 recreational athletes (17 men and 19 women) performing vertical stop-jump tasks. Knee and hip angular motion patterns were determined during the flight phase before landing. RESULTS: Knee and hip motion patterns and quadriceps and hamstring activation patterns exhibited significant gender differences. Female subjects generally exhibited decreased knee flexion (P = .001), hip flexion (P = .001), hip abduction (P = .001), and hip external rotation (P = .03); increased knee internal rotation (P = .001); and increased quadriceps activation (P = .001) compared with male subjects. Female subjects also exhibited increased hamstring activation before landing but a trend of decreased hamstring activation after landing compared with male subjects (P = .001). CONCLUSION: Lower extremity motion patterns during landing of the stop-jump task are preprogrammed before landing. Female subjects prepared for landing with decreased hip and knee flexion at landing, increased quadriceps activation, and decreased hamstring activation, which may result in increased anterior cruciate ligament loading during the landing of the stop-jump task and the risk for noncontact ACL injury.