Noncontact Ankle Sprains Research Articles

Greater knee varus angle and pelvic internal rotation after landing are predictive factors of a non-contact lateral ankle sprain

ObjectivesThis study aimed to clarify the kinematic, kinetic characteristics associated with lateral ankle sprain. DesignA 16-month prospective cohort study. SettingLaboratory. ParticipantsA total of 179 college athletes. Main outcome measuresJoint kinematics, moment during single-leg landing tasks, and ankle laxity were measured. The attendance of each participating team, injury mechanism, existence of body contact, presence of orthosis, with or without medical diagnosis, and periods of absence were recorded. ResultsTwenty-nine participants incurred lateral ankle sprain during non-contact motion. The Cox regression analysis revealed that greater knee varus peak angle (hazard ratio: 1.16 [95% confidence interval: 1.10–1.22], p < 0.001) and greater pelvic internal rotation peak angle toward the support leg were associated with lateral ankle sprain (hazard ratio: 1.08 [95% confidence interval: 1.02–1.15], p = 0.009). The cut-off values for each predictive factor were −0.17° (area under the curve = 0.89, p < 0.001) and 6.63° (area under the curve = 0.74, p < 0.001), respectively. ConclusionsA greater knee varus peak angle and pelvic internal rotation peak angle after single-leg landing are predictive factors for lateral ankle sprain.

Does the Spraino low-friction shoe patch prevent lateral ankle sprain injury in indoor sports? A pilot randomised controlled trial with 510 participants with previous ankle injuries

BackgroundLateral ankle sprains are common in indoor sports. High shoe–surface friction is considered a risk factor for non-contact lateral ankle sprains. Spraino is a novel low-friction patch that can be...

Injury Profile in a Brazilian First-Division Youth Soccer Team: A Prospective Study

Despite the popularity of soccer at the male first-division youth level, data on the incidence of injuries in Brazil are limited. To prospectively study the injury profile of male first-division youth soccer players during 1 season (January to December 2017). Descriptive epidemiology study. Data compiled at a youth soccer academy. The study involved 228 players between 10 and 20 years old from a first-division Brazilian soccer academy. Injury incidence rate was reported as the number of injuries divided by overall exposure (training and match hours) multiplied by 1000. The rate ratio (injury incidence rate during matches in relation to training) was also calculated. Time-loss injuries (ie, physical complaints sustained during soccer matches or training that resulted in a player being unable to take part in soccer training or match play) during the season were recorded. A total of 187 injuries were documented in 122 players (65.2%). During the season, 100 389 hours of exposure (5995 hours of match play and 94 394 of training) were registered. The overall injury incidence rate was 1.86 per 1000 hours. In total, 4792 days were lost from soccer activities. The majority of injuries were noncontact thigh muscle disorders and ankle sprains. Injury incidence was greater in matches than in training, and the oldest age group (under 20 years old) had the highest injury incidence rate in matches, while the under 17-year-old group had the highest injury incidence rate in training sessions (22.48 and 3.05 per 1000 hours, respectively). Muscle injury incidence rates observed among Brazilian soccer athletes under 20 years old were similar to those reported in professional players. Preventive measures are recommended to reduce injury rates. Additionally, the number of injuries incurred during training was high compared with match play, and training programs need to be assessed so that injury prevention can be improved.

The predictive value of the multiple hop test for first-time noncontact lateral ankle sprains

ABSTRACTThe predictive value of the multiple hop test for first-time noncontact lateral ankle sprains. Background: Lateral ankle sprains (LAS) are very common sports injuries, cause high health care costs and are associated with postural control deficits. From a preventive point of view, clinicians should dispose valid field tests to identify athletes at risk for a LAS. The aim of this study is to evaluate the predictive value of the multiple hop test (MHT) for first-time noncontact LAS. Methods: Non-elite athletes (n = 232) performed the MHT at baseline. During a 12-month follow-up period, all noncontact LAS related to health care costs were recorded. Outcomes of the MHT (completion time, balance errors and perceived difficulty) between the injured and uninjured group were compared and odds ratios (OR) and relative risks (RR) were calculated using a logistic regression analysis. Results: Ten first-time noncontact LAS were recorded (4.3%). Injured athletes made significantly more change-in-support strategy (CSS) errors when compared to uninjured athletes (p = .04). The OR of the number of CSS errors was 1.14 (p = .03), the RR 4.1 (p = .04). Conclusions: Athletes scoring > 12 CSS errors, have a four times increased risk for a first-time noncontact LAS. The MHT is a valid field test to identify athletes at risk for a first-time noncontact LAS.

A kinematic analysis of the Spraino® realignment mechanism during simulated noncontact ankle sprain injuries

Sprains to the lateral ligaments of the ankle joint are the most common type of acute musculoskeletal injuries (Vuurberg et al., 2018). These injuries are especially prevalent in indoor sports wher...

The Epidemiology Of Ankle Sprains In Youth, High School, And College Lacrosse

Understanding how ankle sprain injury incidence varies by level of play in male and female lacrosse players is important in informing level- and sport-specific injury prevention strategies. PURPOSE: Describe the epidemiology of ankle sprains in youth, high school (HS), and college lacrosse in the 2014/15-2016/17 seasons. METHODS: Youth data originated from 10 leagues in 5 states (21 boys’ and 21 girls’ team-seasons). HS data originated from the National Athletic Treatment, Injury and Outcomes Network (22 boys’ and 15 girls’ team-seasons). College data originated from the National Collegiate Athletic Association Injury Surveillance Program; 20 men’s and 47 women’s team-seasons). Athletic trainers (ATs) reported athlete-exposure (AE) and injury data from practices and competitions. Injury rate ratios (IRR) compared injury rates by level of play. Sex differences were not examined as these sports have different rules. IRRs with 95% confidence intervals (CI) excluding 1.00 were considered significant. We calculated the proportions of time loss (TL) injuries (resulting in participation restriction time ≥24 hours) and injury mechanism distributions. RESULTS: Ankle sprain rates per 1000AE were 0.77 (n=20), 0.36 (n=13), and 0.54 (n=62) in youth, HS, and collegiate male players, respectively, and 1.20 (n=11), 0.90 (n=20), and 0.56 (n=55) in youth, HS, and collegiate female players, respectively. Ankle sprain rates were higher in youth girls versus college women (IRR=2.15, 95%CI: 1.12-4.11), and youth boys versus HS boys (IRR=2.14, 95%CI: 1.07-4.31). Overall, 50% of ankle sprains in female lacrosse players were TL injuries; proportions of TL injuries in male lacrosse players increased with level of play (40.0%, 62.9% and 71.2%, respectively). Also, 56.2% of male ankle sprains and 39.2% of female ankle sprains were due to non-contact mechanisms. Overall, proportions of player contact-related ankle sprains increased with level of play (6.5%, 18.2%, and 29.1%, respectively). CONCLUSIONS: Ankle sprain rates varied by level of play in male and female lacrosse players. Variations associated with TL injuries and player contact-related injuries may highlight the need for level-specific injury prevention strategies. Future research should target reducing the incidence of non-contact ankle sprains.

Hip Strength as a Predictor of Ankle Sprains in Male Soccer Players: A Prospective Study.

Diminished hip-abductor strength has been suggested to increase the risk of noncontact lateral ankle sprains. To determine prospectively whether baseline hip-abductor strength predicts future noncontact lateral ankle sprains in competitive male soccer players. Prospective cohort study. Athletic training facilities and various athletic fields. Two hundred ten competitive male soccer players. Before the start of the sport season, isometric hip-abductor strength was measured bilaterally using a handheld dynamometer. Any previous history of ankle sprain, body mass index, age, height, and weight were documented. During the sport season (30 weeks), ankle injury status was recorded by team medical providers. Injured athletes were further classified based on the mechanism of injury. Only data from injured athletes who sustained noncontact lateral ankle sprains were used for analysis. Postseason, logistic regression was used to determine whether baseline hip strength predicted future noncontact lateral ankle sprains. A receiver operating characteristic curve was constructed for hip strength to determine the cutoff value for distinguishing between high-risk and low-risk outcomes. A total of 25 noncontact lateral ankle sprains were confirmed, for an overall annual incidence of 11.9%. Baseline hip-abductor strength was lower in injured players than in uninjured players ( P = .008). Logistic regression indicated that impaired hip-abductor strength increased the future injury risk (odds ratio = 1.10 [95% confidence interval = 1.02, 1.18], P = .010). The strength cutoff to define high risk was ≤33.8% body weight, as determined by receiver operating characteristic curve analysis. For athletes classified as high risk, the probability of injury increased from 11.9% to 26.7%. Reduced isometric hip-abductor strength predisposed competitive male soccer players to noncontact lateral ankle sprains.

تأثیر تقویت عضلات دور کننده ران و چرخاننده خارج ران بر آسیب اسپرین خارجی غیر برخوردی مچ پا در فوتبالیست‌ها و فوتسالیست‌های مرد: تحقیق تجربی کنترل شده

Introduction: Ankle sprain is one of the most common injuries in sport activities. Hip abductor and external rotator weakness may compromise lower extremity alignment and balance, and increase the risk of lateral ankle sprain. The purpose of the present study was to investigate the effect of hip abductor and external rotator strengthening on non-contact lateral ankle sprain in male soccer and futsal players. Materials and Methods: This randomized controlled trial study was conducted on 200 soccer and futsal players which were randomly assigned to two groups. Control group participated in pre-season physical conditioning program which were 1 hour, 4 days a week for 8 weeks. Experimental group participated in the same program for 45 minutes and 15 minutes of selected hip abductor and external rotator strengthening program at each session. Hip abductor and external rotator strength was measured before and after 8 weeks of training. All the players were under surveillance for non-contact lateral ankle sprain during the one season of competition. Results: 8 weeks of selected hip abductor and external rotator strengthening program significantly improved hip strength more in experimental group compared to the control group. In addition, the experimental group significantly experienced less non-contact lateral ankle sprain compared to the control group. Conclusion: Adding isolated strengthening of hip abductor and external rotator to general physical conditioning program decrease the risk of non-contact lateral ankle sprain in male soccer and futsal players.

Postural Stability During Single-Leg Stance: A Preliminary Evaluation of Noncontact Lower Extremity Injury Risk.

Study Design Controlled laboratory study with a prospective cohort design. Background Postural stability deficits during single-leg stance have been reported in persons with anterior cruciate ligament (ACL) injury, ACL reconstruction, and chronic ankle instability. It remains unclear whether impaired postural stability is a consequence or cause of these injuries. Objectives To prospectively investigate whether postural stability deficits during single-leg stance predict noncontact lower extremity injuries. Methods Fifty injury-free female athletes performed a transition task from double-leg stance to single-leg stance with eyes closed. Center-of-pressure displacement, the main outcome variable, was measured during the first 3 seconds after the time to a new stability point was reached during single-leg stance. Noncontact lower extremity injuries were recorded at a 1-year follow-up. Results Six participants sustained a noncontact ACL injury or ankle sprain. Center-of-pressure displacement during the first 3 seconds after the time to a new stability point was significantly increased in the injured (P = .030) and noninjured legs (P = .009) of the injured group compared to the respective matched legs of the noninjured group. The area under the receiver operating characteristic curve (AUC) analysis revealed significant discriminative accuracy between groups for the center-of-pressure displacement during the first 3 seconds after the time to a new stability point of the injured (AUC = 0.814, P = .015) and noninjured legs (AUC = 0.897, P = .004) of the injured group compared to the matched legs of the noninjured group. Conclusion This preliminary study suggests that postural stability measurements during the single-leg stance phase of the double- to single-leg stance transition task may be a useful predictor of increased risk of noncontact lower extremity injury. Further research is indicated. Level of Evidence Prognosis, level 4. J Orthop Sports PhysTher 2016;46(8):650-657. Epub 3 Jul 2016. doi:10.2519/jospt.2016.6278.

Hip Abductor Strength Predicts Lateral Non-contact Ankle Sprains in Male Soccer Players

PURPOSE: Deficits in hip abductor strength have been linked to increased risk of lower-extremity injury. We aimed to prospectively determine whether preseason hip abductor strength predicts future lateral non-contact ankle sprains in competitive athletes. METHODS: Prior to the start of the sports season, isometric hip abductor strength was assessed bilaterally in competitive soccer players (210 males) using a hand-held dynamometer. During the sport seasons, lateral ankle sprain status was recorded, and injured athletes were further classified based on the mechanism of injury (non-contact vs. contact). Postseason, a logistic model was constructed to determine whether baseline hip abductor strength predicted future lateral non-contact ankle sprains. A receiver operating characteristic (ROC) curve was constructed for hip abductor strength to determine the clinical cut-off value that distinguished between a high-risk and low-risk outcome. RESULTS: A total of 25 lateral non-contact ankle sprains were confirmed for an overall annual incidence of 11.9%. Baseline hip abductor strength was significantly lower in injured athletes compared to non-injured athletes (35.7 ± 5.6 vs. 39.5 ± 6.6 %BW, p = 0.008). Logistic regression indicated impaired hip abductor strength increased future injury risk [OR = 1.10 (95% CI: 1.02, 1.18), p = 0.010]. The clinical cutoff to define high risk was established as hip abductor strength ≤ 33.8 %BW. Using this cutoff, athletes classified as high risk have their probability of injury increase from 11.9% to 26.7%; whereas; athletes classified as low risk have their probability of injury decrease from 11.9% to 8.0%. CONCLUSIONS: Impaired isometric hip abductor strength predisposes competitive male soccer players to lateral non-contact ankle sprains. Screening procedures should consider evaluating isometric hip abductor strength (specifically for high-level male athletes participating in soccer) as preseason hip abductor predicts future lateral non-contact ankle sprains.

The association between the ACTN3 R577X polymorphism and noncontact acute ankle sprains

Ankle sprains are one of the most severe musculoskeletal soft tissue injuries during physical activity. Although many risk factors have been offered, it is unclear why some individuals develop noncontact ankle sprains when participating in comparable levels of physical exertion under identical environmental conditions and others do not. The ACTN3 gene that encodes the α-actinin-3 protein, which is, only expressed in the Z line of fast glycolytic muscle fibres was found to associate with power/strength performance. The aim of this study was therefore to investigate whether the ACTN3 gene polymorphism is associated with noncontact acute ankle sprains. One hundred and forty-two participants with clinically diagnosed noncontact acute ankle sprains as well as 280 physically active controls participants without any history of ankle sprains were included in this case–control genetic association study. The RR genotype (odds ratio (OR) = 0.56; 95% confidence interval (CI), 0.32–0.65, P = 0.011) and R allele (OR = 0.64; 95% CI, 0.37–0.68, P = 0.002) of the ACTN3 were significantly low-represented in the acute ankle sprains group compared with the control group. The ACTN3 R577X is associated with acute ankle sprains in Chinese participants in this study. This is the first study to suggest that an individual with a RR genotype is at a decreased risk of acute ankle sprains.

INJURY PREVENTION PRACTICE IN FEMALE BASKETBALL PLAYERS IN THE JAPANESE TOP LEAGUE: AN INTERVENTIONAL STUDY OVER 7 SEASONS

BackgroundFemale basketball players are at a higher risk for injuries such as those of the anterior cruciate ligament (ACL). Therefore, preventing such injuries is essential for their health and the...

Intrinsic Predictive Factors of Noncontact Lateral Ankle Sprain in Collegiate Athletes: A Case-Control Study.

Background:Lateral ankle sprain (LAS) is one of the most common injuries in sports. Despite extensive research, intrinsic factors that predict initial and recurrent noncontact LAS remain undefined.Purpose:To identify the predictive factors of initial and recurrent noncontact LAS, focusing on ankle flexibility and/or alignment in collegiate athletes.Study Design:Case-control study; Level of evidence, 3.Methods:A total of 191 athletes were assessed during the preseason for factors predictive of noncontact LAS. The baseline measurements included weightbearing dorsiflexion range of motion (ROM), leg-heel angle, foot internal rotation angle in plantar flexion, classification according to the mortise test, and navicular–medial malleolus (NMM) distance. Occurrence of noncontact LAS and participation in practice and games were prospectively recorded for 11 months.Results:Of the 191 athletes assessed, 169 (145 males, 24 females) completed the study; 125 athletes had a history of ankle sprain. During the observational period, 16 athletes suffered noncontact LAS (0.58 per 1000 athlete-exposures) consisting of 4 initial sprains and 12 recurrences. The hazard ratio estimated by a Cox regression analysis showed that athletes with an NMM distance ≥4.65 cm were 4.14 times more likely to suffer an initial noncontact LAS than were athletes with a shorter NMM distance (95% confidence interval, 1.12-14.30) and that athletes with a weightbearing dorsiflexion ROM >49.5° were 1.12 times as likely to suffer a recurrent noncontact LAS compared with athletes with a lower ROM (95% confidence interval, 1.05-1.20).Conclusion:NMM distance predicts initial noncontact LAS, and weightbearing dorsiflexion ROM predicts recurrent noncontact LAS.

Intrinsic Risk Factors of Noncontact Ankle Sprains in Soccer

Background: Ankle sprain is an extremely common injury in soccer players. Despite extensive research, the intrinsic cause of this injury under noncontact conditions remains unclear. Purpose: To identify intrinsic risk factors for noncontact ankle sprains in professional soccer players. Study Design: Cohort study; Level of evidence, 2 Methods: One hundred professional soccer players were assessed in the preseason for potential risk factors of noncontact ankle sprains. The assessment included (A) ankle joint asymmetries (right-left) in isokinetic muscle strength, flexibility, proprioception, and stability; (B) somatometric asymmetries; (C) previous injuries; and (D) lateral dominance traits. Noncontact ankle sprains were prospectively recorded and diagnosed for a full competition period (10 months). Results: Seventeen of the players sustained at least 1 noncontact ankle sprain. Logistic regression revealed that players with (A) eccentric isokinetic ankle flexion strength asymmetries (odds ratio [OR] = 8.88; 95% confidence interval [CI], 1.95-40.36, P = .005), (B) increased body mass index (OR = 8.16; 95% CI, 1.42-46.63, P = .018), and (C) increased body weight (OR = 5.72; 95% CI, 1.37-23.95, P = .017 ) each had a significantly higher risk of a noncontact ankle sprain. A trend for younger players (OR = 0.28; 95% CI, 0.061-1.24, P = .092) and for players with ankle laxity asymmetries (OR = 3.38; 95% CI, 0.82-14.00, P = .093) to be at greater risk for ankle sprain was also apparent to the limit of statistical significance (.05 < P < .10). Conclusion: Functional strength asymmetries of the ankle flexors and increased body mass index and body weight raise the propensity for ankle sprains in professional soccer players. Age and asymmetries in ankle laxity are potential factors worth revisiting, as there was an indication for younger players and players with ankle instability to be at higher risk for ankle injury. Proper preseason evaluation may improve prevention strategies for this type of injury in soccer.

Effect of Neuromuscular Warm-up on Injuries in Female Soccer and Basketball Athletes in Urban Public High Schools

To determine the effectiveness of coach-led neuromuscular warm-up on reducing lower extremity (LE) injuries in female athletes in a mixed-ethnicity, predominantly low-income, urban population. Cluster randomized controlled trial. Chicago public high schools. Of 258 coaches invited to participate, 95 (36.8%) enrolled (1558 athletes). Ninety coaches and 1492 athletes completed the study. We randomized schools to intervention and control groups. We trained intervention coaches to implement a 20-minute neuromuscular warm-up. Control coaches used their usual warm-up. Coach compliance was tracked by self-report and direct observation. Coaches reported weekly athlete exposures (AEs) and LE injuries causing a missed practice or game. Research assistants interviewed injured athletes. Injury rates were compared between the control and intervention groups using χ(2) and Fisher exact tests. Significance was set at P < .05. Poisson regression analysis adjusted for clustering and covariates in an athlete subset reporting personal information (n = 855; 57.3%). There were 28 023 intervention AEs and 22 925 control AEs. Intervention coaches used prescribed warm-up in 1425 of 1773 practices (80.4%). Intervention athletes had lower rates per 1000 AEs of gradual-onset LE injuries (0.43 vs 1.22, P < .01), acute-onset noncontact LE injuries (0.71 vs 1.61, P < .01), noncontact ankle sprains (0.25 vs 0.74, P = .01), and LE injuries treated surgically (0 vs 0.17, P = .04). Regression analysis showed significant incidence rate ratios for acute-onset noncontact LE injuries (0.33; 95% CI, 0.17-0.61), noncontact ankle sprains (0.38; 95% CI, 0.15-0.98), noncontact knee sprains (0.30; 95% CI, 0.10-0.86), and noncontact anterior cruciate ligament injuries (0.20; 95% CI, 0.04-0.95). Coach-led neuromuscular warm-up reduces noncontact LE injuries in female high school soccer and basketball athletes from a mixed-ethnicity, predominantly low-income, urban population. TRIAL REGISTRATION CLINICALTRIALS.ORG IDENTIFIER: NCT01092286.

The Effectiveness of a Balance Training Intervention in Reducing the Incidence of Noncontact Ankle Sprains in High School Football Players

Background A high body mass index and previous ankle sprains have been shown to increase the risk of sustaining noncontact inversion ankle sprains in high school football players. Hypothesis Stability pad balance training reduces the incidence of noncontact inversion ankle sprains in football players with increased risk. Study Design Cohort study; Level of evidence, 2. Methods Height, body mass, history of previous ankle sprains, and current ankle brace/tape use were documented at the beginning of preseason training in 2 high school varsity football teams for 3 consecutive years (175 player-seasons). Players were categorized as minimal risk, low risk, moderate risk, and high risk based on the history of previous ankle sprain and body mass index. Players in the low-, moderate-, and high-risk groups (ie, any player with a high body mass index and/or a previous ankle sprain) were placed on a balance training intervention on a foam stability pad. Players balanced for 5 minutes on each leg, 5 days per week, for 4 weeks in preseason and twice per week during the season. Postintervention injury incidence was compared with preintervention incidence (107 players-seasons) for players with increased risk. Results Injury incidence for players with increased risk was 2.2 injuries per 1000 exposures (95% confidence interval, 1.1-3.8) before the intervention and 0.5 (95% confidence interval, 0.2-1.3) after the intervention (P < .01). This represents a 77% reduction in injury incidence (95% confidence interval, 31%-92%). Conclusion The increased risk of a noncontact inversion ankle sprain associated with a high body mass index and a previous ankle sprain was eliminated by the balance training intervention.

Risk Factors for Noncontact Ankle Sprains in High School Football Players: The Role of Previous Ankle Sprains and Body Mass Index

Risk Factors for Noncontact Ankle Sprains in High School Football Players: The Role of Previous Ankle Sprains and Body Mass Index

Risk Factors for Noncontact Ankle Sprains in High School Athletes: The Role of Hip Strength and Balance Ability

Risk Factors for Noncontact Ankle Sprains in High School Athletes: The Role of Hip Strength and Balance Ability

Risk Factors for Noncontact Ankle Sprains in High School Athletes

Background Ankle sprains are among the most common sports injuries. Hypothesis Poor balance as measured on a balance board and weakness in hip abduction strength are associated with an increased risk of noncontact ankle sprains in high school athletes. Study Design Cohort study; Level of evidence, 2. Methods One hundred sixty-nine high school athletes (101 male athletes, 68 female athletes) from football, men's basketball, men's soccer, women's gymnastics, women's basketball, and women's soccer were observed for 2 years. Balance in single-limb stance on an instrumented tilt board and hip flexion, abduction, and adduction strength (handheld dynamometer) were assessed in the preseason. Body mass, height, generalized ligamentous laxity, previous ankle sprains, and ankle tape or brace use were also documented. Results There were 20 noncontact inversion ankle sprains. Balance ability (P= .72), hip abduction strength (P= .66), hip adduction strength (P= .41), and hip flexion strength (P= .87) were not significant risk factors for ankle sprains. The incidence of grade II and grade III sprains was higher in athletes with a history of a previous ankle sprain (1.12 vs 0.26 per 1000 exposures, P< .05). A higher body mass index in male athletes was associated with increased risk (P< .05). The combination of a previous injury and being overweight further increased risk (P< .01). Conclusion Balance as measured on a balance board and hip strength were not significant indicators for noncontact ankle sprains. The apparent high injury risk associated with the combination of a history of a previous ankle sprain and being overweight in male athletes warrants further examination.

Risk Factors for Noncontact Ankle Sprains in High School Football Players

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.