Previous Lower Extremity Injury Research Articles

Poster 358: Minutes Per Game and Usage Rate Associated with Time Loss after Ankle Injury: A Characterization of Foot and Ankle Injuries and Associated Risk Factors in National Basketball Association Athletes

Objectives: Injuries to the foot and ankle are more common in National Basketball Association (NBA) basketball compared to other professional sports. The goal of this study is to report the incidence and associated risk factors of foot and ankle injuries in the NBA athletes. Methods: Foot and ankle injury data from the 2015-16 through 2020-21 NBA seasons was queried and verified using a publicly available database. The truncated 2019-20 season was omitted from this study due to the COVID-19 pandemic. The primary outcome was the incidence of foot and ankle injuries, reported per 1000 game exposures (GEs). Secondary analysis was performed to identify risk factors for ankle injuries through bivariate analysis and multivariable logistic regression of player demographics, performance statistics, injury characteristics, and previous lower extremity injuries. Additionally, factors influencing the length of absence were assessed via negative binomial regression. Results: There were 728 structural foot and ankle injuries (5.34 per 1000 GEs) sustained by NBA players over 5 NBA seasons, with sprain/strain as the most common injury type (4.27 per 1000 GEs) (Table 1). The majority of ankle injury events (55%) resulted in 2-10 game absences (Table 4). The likelihood of sustaining an ankle injury was significantly associated with a greater number of games played, previous upper leg injury, and more games missed due to injury (Table 2). Increased length of absence due to ankle injury was significantly associated with greater height, minutes per game, usage rate, points per game, total rebounds per game, and a prior history of foot, ankle, and knee injuries (Table 3). Conclusions: The incidence of foot and ankle injuries was 5.34 per 1000 GEs in professional basketball players. Games played and previous history of upper leg injuries were found to be risk factors for ankle injuries. Factors associated with physiologic burden such as minutes per game and usage rate were associated with an increased severity of injury. [Table: see text][Table: see text][Table: see text][Table: see text]

Characterization of Ankle Injuries and Associated Risk Factors in the National Basketball Association: Minutes Per Game and Usage Rate Associated With Time Loss.

Ankle injuries are more common in the National Basketball Association (NBA) compared with other professional sports. The purpose of this study was to report the incidence and associated risk factors of ankle injuries in NBA athletes. It was hypothesized that factors associated with an increased physiologic burden, such as minutes per game (MPG), usage rate, and associated lower extremity injury, would be associated with increased ankle injury risk and time loss. Descriptive epidemiology study. Ankle injury data from the 2015-2016 through 2020-2021 NBA seasons were evaluated. The truncated 2019-2020 season due to the COVID-19 pandemic was omitted. The primary outcome was the incidence of ankle injuries, reported per 1000 game-exposures (GEs). Secondary analysis was performed to identify risk factors for ankle injuries through bivariate analysis and multivariable logistic regression of player demographic characteristics, performance statistics, injury characteristics, and previous lower extremity injuries. Factors influencing the time loss after injury were assessed via a negative binomial regression analysis. A total of 554 ankle injuries (4.06 injuries per 1000 GEs) were sustained by NBA players over 5 NBA seasons, with sprain/strain the most common injury type (3.71 injuries per 1000 GEs). The majority of ankle injury events (55%) resulted in 2 to 10 game absences. The likelihood of sustaining an ankle injury was significantly associated with a greater number of games played (P = .029) and previous injury to the hip, hamstring, or quadriceps (P = .004). Increased length of absence due to ankle injury was associated with greater height (P = .019), MPG (P < .001), usage rate (P = .025), points per game (P = .011), and a prior history of foot (P = .003), ankle (P < .001), and knee injuries (P < .001). The incidence of ankle injuries was 4.06 per 1000 GEs in professional basketball players. Games played and prior history of hip, hamstring, or quadriceps injuries were found to be risk factors for ankle injuries. Factors associated with physiologic burden such as MPG and usage rate were associated with an increased time loss after injury.

Demographic Characteristics and Their Association with Instantaneous Lower Extremity Injury Occurrence in a Division I Athletic Population.

Temporal prediction of lower extremity (LE) injury risk will benefit clinicians by allowing them to better leverage limited resources and target athletes most at risk. To characterize instantaneous risk of LE injury by demographic factors sex, sport, body mass index (BMI), and previous injury history. Instantaneous injury risk was defined as injury risk at any given point in time following baseline measurement. Descriptive epidemiology study. NCAA Division I athletic program. 278 NCAA Division I varsity student-athletes (119 males, 159 females). LE injuries were tracked for 237±235 days. Sex-stratified univariate Cox regression models investigated the association between time to first LE injury and BMI, sport, and previous LE injury history. Relative risk ratios and Kaplan-Meier curves were generated. Variables identified in the univariate analysis were included in a multivariate Cox regression model. Females displayed similar instantaneous LE injury risk compared to males (HR=1.29, 95%CI=[0.91,1.83], p=0.16). Overweight athletes (BMI>25 kg/m2) had similar instantaneous LE injury risk compared with athletes with BMI<25 kg/m2 (HR=1.23, 95%CI=[0.84,1.82], p=0.29). Athletes with previous LE injuries were not more likely to sustain subsequent LE injury than athletes with no previous injury (HR=1.09, 95%CI=[0.76,1.54], p=0.64). Basketball (HR=3.12, 95%CI=[1.51,6.44], p=0.002) and soccer (HR=2.78, 95%CI=[1.46,5.31], p=0.002) athletes had higher risk of LE injury than cross-country athletes. In the multivariate model, females were at greater LE injury risk than males (HR=1.55, 95%CI=[1.00,2.39], p=0.05), and males with BMI>25 kg/m2 were at greater risk than all other athletes (HR=0.44, 95%CI=[0.19,1.00], p=0.05). In a collegiate athletic population, previous LE injury history was not a significant contributor to risk of future LE injury, while being female or being male with BMI>25 kg/m2 resulted in increased risk of LE injury. Clinicians can use these data to extrapolate LE injury risk occurrence to specific populations.

Relationship Between Sensory Organization Testing Scores With Lower Extremity Injuries and Prior Concussion in Professional Soccer Players.

To evaluate for associations between concussion history or lower extremity (LE) injury and computerized sensory organization testing (SOT) performance in professional soccer players. Cross-sectional study. Tertiary care center. Thirty-three, professional, male soccer players on an American club, between the years 2019 and 2021. Player age, history of reported LE injury (gluteal, hamstring, ankle, knee, hip, groin, and sports hernia), history of diagnosed concussion, and the number of prior concussions were documented for each player. Baseline SOT of postural sway was conducted in 6 sensory conditions for all players. Eleven athletes (33%) reported a previous concussion, and 15 (45%) reported a previous LE injury. There were no significant differences in SOT scores between those with and without a previous diagnosis of concussion ( P > 0.05). Those reporting a previous LE injury performed better on condition 3 (eyes open, unstable visual surround) than those who did not ( P = 0.03). Athletes aged 25 years or younger performed worse on condition 3 ( P = 0.01) and had worse, although not statistically significant, median performance on all other balance measures than those older than 25 years. Intraclass correlation coefficient for repeat SOT assessment was 0.58, indicating moderate reliability, without an evident practice effect. Professional soccer players with a previous concussion or history of LE injury did not demonstrate long-term deficits in postural control, as assessed by multiyear computerized SOT baseline testing. The SOT was reliable over time with younger athletes exhibiting greater postural sway than older athletes.

Recovery, Rehabilitation, and Return to Full Duty in a Military Population After a Recent Injury: Differences Between Lower-Extremity and Spine Injuries

PurposeTo compare readiness to return to duty in soldiers following recent lower-extremity versus spine injury. The secondary purposes were to provide normative data for the Selective Functional Movement Assessment Top Tier movements (SFMA-TTM) and assess the association between SFMA-TTM scores and future injury occurrence, comparing injuries of the lower extremity and thoracic/lumbar spine.MethodsSFMA was rated by trained assessors on 480 U.S. Army soldiers within 2 weeks of being cleared to return to duty after recent lower-extremity or lumbar/thoracic injury. Participants were followed for 1 year to determine incidence of subsequent time-loss injury.ResultsOnly 74.4% of soldiers felt 100% mission capable when returning to full duty (73.6% lower-extremity; 76.5% spine). After 1 year, 37.9% had sustained a time-loss injury, and pain with movement at baseline was associated with higher odds for having an injury (odd ratio 1.53 95% confidence interval 1.04-2.24; P = .032). Almost all (99.8%) had at least 1 dysfunctional pattern, and 44.1% had pain with at least 1 movement (40.3% with previous lower-extremity injury; 54.6% with previous spine injury) after being cleared to return to duty.ConclusionsOne in four patients did not feel 100% mission capable upon being cleared for full duty. Pain with movement was also associated with future injury. Regardless of recent injury type, 99.8% of soldiers returned to full unrestricted duty with at least 1dysfunctional movement pattern and 44.1% had pain with at least 1 of the SFMA-TTM movements.Level of EvidenceLevel III, retrospective comparative cohort study.

Association of lower extremity injuries and injury mechanism with previous concussion history in adolescent athletes

ObjectiveDetermine the association between concussion and subsequent contact, non-contact, and overuse lower extremity (LE) injuries in a cohort of adolescent athletes. Secondarily, to identify this association between males and females. Study designCross-sectional. SettingSummer athletic events with participants ages 12–18. Main outcomeAnonymous survey included sport-related injuries (injury month/year) and participants classified injuries as a contact, non-contact, overuse injury, or concussion. Multivariable logistic regression analyses were used to examine associations between a concussion event and a subsequent LE injury while controlling for age and any previous LE injury. ResultsA concussion was reported in 219 athletes (Female = 96, 44%) and were matched with 219 non-concussed athletes (438 total participants). Concussion was not association with a specific injury mechanism but was significant for any subsequent LE injury (OR = 1.58 95%CI = [1.03–2.41]; p < 0.05). Concussed females were more likely to report any subsequent LE injury compared to non-concussed female athletes (2.49[1.31, 4.74]; p < 0.01). This relationship was not observed between concussed and non-concussed males (1.11[0.62–1.99]; p > 0.5). ConclusionA history of concussion was associated with any subsequent LE injury, but not associated with a specific mechanism of injury. The association with concussion and a subsequent LE injury was different between males and females.

TUCK JUMP ASSESSMENT AS AN INDICATOR OF PREVIOUS UPPER EXTREMITY INJURY

Background: When using the tuck jump as a dynamic movement assessment, clinicians note movement flaws to determine injury potential and provide further training in attempt to improve movement technique deficits. The Tuck Jump Assessment has been identified as a dynamic assessment for lower extremity injury susceptibility.[3-6] The purpose of the Tuck Jump Assessment is to identify postural neuromuscular imbalances, throughout the dynamic movement, that could potentially result in greater injury susceptibility.[5] With the focus of neuromuscular imbalances on Tuck Jump Assessment performance, as well as the common notion of the body acting as a kinetic chain functions most efficient when there is proximal stability for distal mobility,[1] it was our purpose to determine if the Tuck Jump Assessment can be used as a dynamic movement assessment to ascertain a previous history of upper extremity injury in overhead throwing sports such as baseball and softball. We hypothesized that a more flexed trunk and less elevated upper leg in the peak of the tuck jump would correlate with previous history of upper extremity injury for the overhead athlete. Methods: Seventy-one youth baseball and softball athletes (28 baseball/43 softball; 12.41 ± 2.22 yrs.; 161.98 ± 13.65 cm; 59.17 ± 14.90 kg) were recruited to participate. All participants were in good physical condition and had no injuries within the last six months. A health history form was completed by the participants prior to participation. If a participant indicated that they have had an upper extremity injury in the past year that had kept them from competition, then they were placed in the previous injury group (N = 18). All other participants were placed into the no previous injury group (N = 53). Participants that indicated they had a previous lower extremity injury were excluded from of the study. The University’s Institutional Review Board approved all testing protocols. Informed written consent was obtained from each participant and participant’s parents before testing.[2] Kinematic data were collected at 100 Hz using an electromagnetic tracking system (trakSTARTM, Ascension Technologies, Inc., Burlington, VT, USA) synced with the MotionMonitor® (Innovative Sports Training, Chicago, IL. USA). Participants were instructed to start with their feet shoulder width apart and initiate the jump with a slight downward crouch while holding their arms in front of their chest. As they jumped, they were instructed to pull their knees as high as possible during the jump aiming to reach a position where their thighs were parallel to the ground and to immediately begin the next tuck jump once landing.[5] A trial of 10 tuck jumps was collected. Analysis included jumps 4 through 8 to mitigate the Hawthorne effect. Values for trunk flexion and upper leg elevation were taken from peak leg elevation and averaged and a priori was set at a level of p = 0.05 to determine significance. Results: A logistic regression showed no significance in trunk flexion or upper leg elevation being able to determine upper extremity injury (&amp;[Chi] &amp;[sup]2 (&amp;[sub]1, N = 71) = 3.55, p = .315). The model explained 7.2% of the variance in upper extremity injury and correctly classified 73.2% of all cases. Conclusion/Significance: While a direct link was not found between the Tuck Jump Assessment and upper extremity injury, further investigation into injury precursors should be performed. During our Tuck Jump Assessment, we only examined trunk flexion and upper leg elevation, which are two variables that make up the proximal control factor indicated by Lininger and colleagues. [3] In their exploratory factor analysis, it was concluded that three factors defined as fatigue, distal landing pattern, and proximal control should be examined to get the most benefit of the Tuck Jump Assessment in injury assessments.[3] Our results agree with their conclusion, that a simplified unidimensional construct of the Tuck Jump Assessment may not be the best way to use this dynamic movement assessment to identify previous upper extremity injury. In conclusion, examining only trunk flexion and upper leg elevation during the Tuck Jump Assessment is not enough for clinicians to recognize previous upper extremity injury. Even though the body behaves as a kinetic chain, simplifying the dynamic movement assessment while not specifying the type of upper extremity injury is not favorable for the clinician to identify previous injury. References Chu SK et al. PM R. 2016;8(3 Suppl): S69-77. Harris D et al. Int J Sports Med. 2017;38:1126-1131. Lininger MR et al. J Strength Cond Res. 2017;31(3):653-659. Myer GD et al. Strength and Conditioning Journal. 2011;33(3):21-35. Myer GD et al. Athl Ther Today. 2008;13(5):39-44. Myer GD et al. Am J Sports Med. 2010;38(19):2025-2033.

The Relationship between Previous Lower Extremity Injury, Body Weight and Bilateral Eccentric Hamstring Strength Imbalance in Young Soccer Players

The Relationship between Previous Lower Extremity Injury, Body Weight and Bilateral Eccentric Hamstring Strength Imbalance in Young Soccer Players

Prevention of Ankle Sprain Injuries in Youth Soccer and Basketball: Effectiveness of a Neuromuscular Training Program and Examining Risk Factors.

The primary objective of this study was to examine the effectiveness of a neuromuscular training (NMT) warm-up program in reducing the risk of ankle sprain injury (ASI) in youth soccer and basketball. The secondary objective included the evaluation of risk factors for ASI. Secondary analysis of pooled data from 5 studies. Male and female youth (11-18 years) soccer and basketball players (n = 2265) in Alberta, Canada. Ankle sprain injury was the primary outcome and was recorded using a validated prospective injury surveillance system consistent in all studies. The primary exposure of interest was NMT warm-up, which included aerobic, strength, agility, and balance components. Multivariable Poisson regression, controlling for clustering by team and offset for exposure hours, was used to estimate incidence rate ratios (IRRs) with 95% confidence intervals (CIs), with considerations for confounding and effect modification and evaluating all covariates as potential risk factors. A total of 188 ASIs were reported in 171 players. Neuromuscular training significantly reduced the risk of ASI [IRR = 0.68 (95% CI; 0.46-0.99)]. Independent risk factors for ASI included previous ASI [IRR = 1.98 (95% CI; 1.38-2.81)] and participation in basketball versus soccer [IRR = 1.83 (95% CI; 1.18-2.85)]. Sex, age, body mass index, and previous lower extremity injury (without previous ASI) did not predict ASI (P > 0.05). Exposure to an NMT program is significantly protective for ASI in youth soccer and basketball. Risk of ASI in youth basketball is greater than soccer, and players with a history of ASI are at greater risk.

Effects of Recent Concussion and Injury History on Instantaneous Relative Risk of Lower Extremity Injury in Division I Collegiate Athletes.

Growing evidence suggests that concussion increases the risk of lower extremity (LE) musculoskeletal injury. However, it is unclear to how the effect of concussion on LE injury risk may be influenced by previous injuries. This study sought to examine the association between concussion, previous LE injuries, and the risk LE injury to the same previously injured limb (ipsilateral) or the opposite limb (contralateral). This retrospective study examined medical records from 110 concussed athletes and 110 matched controls for LE injuries in the 365 days before and after the concussion event. The effect of concussion on time to injury was assessed with a Cox proportional hazard model after adjusting for injury history. Fine and Gray subdistribution models assessed the cumulative risk of ipsilateral and contralateral injury by group. Concussion was associated with an increased instantaneous relative risk of LE injury when adjusting for LE injury history [hazard ratio (HR) = 1.67, 95% confidence interval (CI) = 1.11-2.53], agreeing with previous results. Among individuals who had a history of LE injuries before the concussion event, a nonsignificant yet moderate effect of concussion on the instantaneous relative risk of ipsilateral injuries was found after adjusting for the competing risk of contralateral injuries and censored values (HR = 1.85, 95% CI = 0.76-4.46). This study provides independent confirmation of previous studies, reporting an association between concussion and LE injury risk. Furthermore, this study suggests that future large-scale studies should consider the competing risk of ipsilateral, contralateral, and new injuries in populations with an injury history.

The Effect of Sport Specialization on Lower Extremity Injury Rates in High School Athletes

Objectives:Sport specialization has been shown to be associated with increased risk of musculoskeletal lower extremity injuries (LEI) in adolescent athletes presenting in clinical settings. However, the association of sport specialization and incidence of LEI has not been studied prospectively in a large population of adolescent athletes. The objective of this study was to compare the incidence of LEI in high school athletes identified as having low (LOW), moderate (MOD) or high (HIGH) levels of sport specialization.Methods:Subjects (male and female, interscholastic athletes, grades 9 - 12) were recruited from a diverse sample of 29 Wisconsin high schools during the 2015/16 school year to participate in the study. Subjects d a questionnaire identifying all of the interscholastic and club sports they participated in during the previous and current school years, history of previous LEI, their primary sport and the number of primary sport competitions in which they participated in within the previous 12 months. Sport specialization status was determined using a previously published 3 item specialization scale (total score: 0 - 1 = LOW, 2 = MOD, 3 = HIGH). Athletic trainers at each school reported all athletic exposures and LEI that occurred for each subject during each interscholastic sport season they participated in during the school year. Analyses included group proportions, Odds Ratios (OR, [95%CI]) and median days lost due to injury (Med [IQR 25th,75th]. Multivariate Cox Proportional Hazards Ratios (HR, [95%CI]) were calculated to investigate the association between the incidence of LEI and sport specialization level while controlling for gender, grade, history of previous LEI, primary sport and the number of primary sport competitions.Results:A total of N =1,544 subjects (Female = 50%, Age =16.1+1.1 yrs.) enrolled in the study, competed in 2,843 athletic seasons and participated in 167,349 athletic exposures during the school year. Subjects were classified as being LOW (60%), MOD (27%) or HIGH (13%) specialization. Females were more likely to be classified as HIGH than males (OR = 2.07 [1.53 - 2.81, p < 0.001]. The sports with the greatest percentage of HIGH participants were soccer (22%), baseball/softball (19%), volleyball (17%), and basketball (13%). Two hundred thirty five subjects (15%) sustained a total of n = 276 LEI that caused them to miss a median of 7.0 [2.0, 22.8] days. Injuries occurred most often to the ankle (34%), knee (25%), upper leg (13%) and lower leg (12%). LEI were acute (66%) or gradual / recurrent (34%) onset. Common injuries included ligament sprains (41%), muscle / tendon strains (25%) and tendonitis / tenosynovitis (20%). Surgical treatment was required for n = 23 (8%) of the LEI. The incidence of LEI for MOD subjects was higher than LOW subjects (HR = 1.51 [1.04 - 2.20], p = 0.029). The incidence of LEI for HIGH subjects was higher than LOW subjects (HR = 1.85 [1.12 - 3.06], p = 0.017).Conclusion:Interscholastic athletes with MOD or HIGH sport specialization were more likely to sustain a LEI than athletes with LOW specialization. Sports medicine providers need to educate officials of sport governing bodies, school coaches, parents and interscholastic athletes regarding the increased risk of LEI for athletes who specialize in a single sport.

Association of Competition Volume, Club Sports, and Sport Specialization With Sex and Lower Extremity Injury History in High School Athletes.

Background:High school athletes are increasingly encouraged to participate in 1 sport year-round to increase their sport skills. However, no study has examined the association of competition volume, club sport participation, and sport specialization with sex and lower extremity injury (LEI) in a large sample of high school athletes.Hypothesis:Increased competition volume, participating on a club team outside of school sports, and high levels of specialization will all be associated with a history of LEI. Girls will be more likely to engage in higher competition volume, participate on a club team, and be classified as highly specialized.Study Design:Cross-sectional study.Level of Evidence:Level 3.Methods:High school athletes completed a questionnaire prior to the start of their competitive season regarding their sport participation and previous injury history. Multivariable logistic regression analyses were used to investigate associations of competition volume, club sport participation, and sport specialization with history of LEI, adjusting for sex.Results:A cohort of 1544 high school athletes (780 girls; grades 9-12) from 29 high schools completed the questionnaire. Girls were more likely to participate at high competition volume (23.2% vs 11.0%, χ2 = 84.7, P < 0.001), participate on a club team (61.2% vs 37.2%, χ2 = 88.3, P < 0.001), and be highly specialized (16.4% vs 10.4%, χ2 = 19.7, P < 0.001). Athletes with high competition volume, who participated in a club sport, or who were highly specialized had greater odds of reporting a previous LEI than those with low competition volume (odds ratio [OR], 2.08; 95% CI, 1.55-2.80; P < 0.001), no club sport participation (OR, 1.50; 95% CI, 1.20-1.88; P < 0.001), or low specialization (OR, 2.58; 95% CI, 1.88-3.54; P < 0.001), even after adjusting for sex.Conclusion:Participating in high sport volume, on a club team, or being highly specialized was associated with history of LEI. Girls were more likely to participate at high volumes, be active on club teams, or be highly specialized, potentially placing them at increased risk of injury.Clinical Relevance:Youth athletes, parents, and clinicians should be aware of the potential risks of intense, year-round participation in organized sports.

Sex Differences in Competition Volume, Club Sport Participation, Specialization, and Injury Among High School Athletes

Female adolescent athletes are at greater risk for certain injuries, such as ACL injuries or overuse knee injuries. One theory for this increased risk is the increasing trend towards intense, year-round sport participation and specialization. However, it is unknown whether characteristics of sport participation, including competition volume, club sport participation, specialization, or history of lower extremity injury (LEI) differ between female and male athletes. PURPOSE: To compare level of competition volume, club sport participation, sport specialization, and previous lower LEI between males and females in high school athletes. METHODS: 1525 high school athletes (780 female, age=16.1±1.1 years old, grades 9-12) from 29 high schools were recruited to complete a pre-season questionnaire regarding their sport participation patterns and previous injury history. Sport competition volume in the previous 12 months was classified as high (>60 competitions), moderate (30-60 competitions), or low (<30 competitions). Sport specialization status was classified as low, moderate, or high using a widely utilized 3-point specialization scale. Chi-square tests were used to investigate associations of competition volume, club sport participation, specialization, and LEI by sex (a-priori p<.05). RESULTS: Females were more likely than males to participate in high competition volume (23.2% vs 11.0%, χ2=84.7, p<0.001), participate on a club team (61.2% vs 37.2%, χ2=88.3, p<0.001), and be highly specialized (16.4% vs 10.4%, χ2=19.7, p<0.001). A total of 487 subjects (31.5%) reported sustaining a total of 599 previous time-loss LEI. Female athletes were more likely to report a previous LEI than males when considering all sports (36.5% vs. 27.0%, χ2=15.9, p<0.001) and when the sample was restricted to sex-equivalent sports (37.3% vs. 28.2%, χ2=9.0, p=0.003). CONCLUSIONS: Female athletes were more likely to participate in sports at high volumes, on club teams in addition to their high school teams, be highly specialized, and report previous LEI. Female high school athletes may be at greater risk of injury due to these differences in sport participation patterns. Supported by grants from the American Medical Society for Sports Medicine and the National Federation of State High School Associations.

Sex Differences in Competition Volume, Club Sport Participation, Specialization, and Injury Among High School Athletes

Female adolescent athletes are at greater risk for certain injuries, such as ACL injuries or overuse knee injuries. One theory for this increased risk is the increasing trend towards intense, year-round sport participation and specialization. However, it is unknown whether characteristics of sport participation, including competition volume, club sport participation, specialization, or history of lower extremity injury (LEI) differ between female and male athletes. PURPOSE: To compare level of competition volume, club sport participation, sport specialization, and previous lower LEI between males and females in high school athletes. METHODS: 1525 high school athletes (780 female, age=16.1 ± 1.1 years old, grades 9-12) from 29 high schools were recruited to complete a pre-season questionnaire regarding their sport participation patterns and previous injury history. Sport competition volume in the previous 12 months was classified as high (>60 competitions), moderate (30-60 competitions), or low (<30 competitions). Sport specialization status was classified as low, moderate, or high using a widely utilized 3-point specialization scale. Chi-square tests were used to investigate associations of competition volume, club sport participation, specialization, and LEI by sex (a-priori p<.05). RESULTS: Females were more likely than males to participate in high competition volume (23.2% vs 11.0%, χ2=84.7, p < 0.001), participate on a club team (61.2% vs 37.2%, χ2=88.3, p<0.001), and be highly specialized (16.4% vs 10.4%, χ2=19.7, p < 0.001). A total of 487 subjects (31.5%) reported sustaining a total of 599 previous time-loss LEI. Female athletes were more likely to report a previous LEI than males when considering all sports (36.5% vs. 27.0%, χ2=15.9, p < 0.001) and when the sample was restricted to sex-equivalent sports (37.3% vs. 28.2%, χ2=9.0, p = 0.003). CONCLUSIONS: Female athletes were more likely to participate in sports at high volumes, on club teams in addition to their high school teams, be highly specialized, and report previous LEI. Female high school athletes may be at greater risk of injury due to these differences in sport participation patterns. Supported by grants from the American Medical Society for Sports Medicine and the National Federation of State High School Associations.

Effects of Previous Lower Extremity Injury on Functional Movement Screening Results

Effects of Previous Lower Extremity Injury on Functional Movement Screening Results

The Efficacy Of Performance On Clinical Hop Tests To Predict Previous Lower Extremity Injury

The Efficacy Of Performance On Clinical Hop Tests To Predict Previous Lower Extremity Injury

Injury Risk In Athletes With And Without A History Of Lower Extremity Injury

Previous injury has been shown to be a risk factor for subsequent injury. Female basketball athletes are at greatest risk for injury during puberty, generally ages 10–17, and are 3.5 times more likely to injure an anterior cruciate ligament than their male counterparts. Landing technique has been shown to identify lower extremity (LE) injury risk in youth athletes. PURPOSE: To compare injury risk of female youth basketball athletes with and without history of LE injury. METHODS: Sixty-five female basketball athletes volunteered to participate in a single test session during which they completed a questionnaire regarding injury history and performed a jump-landing task videotaped from the front and side. Previous LE injury history was defined as any self-reported injury to the foot, ankle, lower leg, knee, thigh or hip. A single rater blinded to injury history graded all videos using the Landing Error Scoring System (LESS). Separate independent t-tests compared athletes with and without LE injury history, with knee injury history and no LE injury history, and with ankle injury history and no LE injury history (α=0.05). RESULTS: Forty athletes reported history of LE injury (13±1 yr, 165.7±9.8 cm, 57.4±13.9 kg), of which 20 reported history of knee injury (14±2 yr, 167.5±8.8 cm, 61.8±15.7 kg) and 24 reported history of ankle injury (14±2 yr, 167.6±10.0 cm, 60.6±15.7 kg). Twenty-five athletes reported no history of LE injury (12±2 yr, 161.3±9.9 cm, 52.6±12.5 kg). No significant differences in LESS score were observed between athletes with (5.2±1.8 errors) and without (5.3±2.2 errors) history of LE injury (p>0.05, mean difference= 0.12±0.5 errors, 95%CI [−0.9, 1.1]) No significant differences in LESS score were found between athletes with history of knee injury and with no history of LE injury (p>0.05, mean difference= −0.124±0.7 errors, 95%CI [−1.4, 1.2]) as well as athletes with history of ankle injury and no history of LE injury (p>0.05, mean difference= 0.5±0.6 errors, 95%CI [−0.7, 1.6]). CONCLUSION: History of LE, knee or ankle injury did not increase injury risk compared to athletes with no LE injury history. Our results do not support previous findings that prior LE injury increases risk of subsequent injury. Further research is needed to evaluate the impact of LE injury history on injury risk in at-risk populations.

Risk Factors for Sustaining a Lower Extremity Injury in an Army Reserve Officer Training Corps Cadet Population.

Injuries acquired during Reserve Officer Training Corps (ROTC) participation can potentially affect a cadet's future and career in the armed forces. The purpose of this study was to identify risk factors associated with lower extremity injuries in an Army ROTC cadet population. There were 195 (165M, 30F) cadets enrolled in an Army ROTC program, 18 to 33 years old, with an average body mass index (BMI) of 23.5 ± 2.85. Injury data were retrospectively obtained from the electronic medical records maintained by a Certified Athletic Trainer. Descriptive statistics, frequencies, and incidence rate for physical training (PT) were calculated. Survival analysis determined association between injury and several variables (Military Science [MS] year, army physical fitness test scores, BMI, sex, previous lower extremity injury, PT exposures, most frequent boot worn, current and prior physical activity, and collision sport participation). Kaplan-Meier curves were used for the categorical variables. Incidence rate was 60 lower extremity injuries/100 person-years during PT. The survival analysis revealed MS year (p < 0.001) and PT exposures (p < 0.001) were significant in predicting risk of injury. All other variables were not significant. On the basis of this preliminary data, footwear and activity have no implications on risk of lower extremity injury. Preventative measures should be focused toward younger cadets because of their increased risk for injury.

Relationships Among Injury History, Flexibility And Fms Score In College Dance Majors

Dancers are at an increased risk of low back pain (LBP) and lower extremity (LE) musculoskeletal injuries due to repetitive high velocity end range movements. Previous injuries, movement pattern inefficiency (poor movement control), and excessive flexibility are suggested contributors to injury in dancers. The Functional Movement Screen (FMS) is a tool used to assess functional movement performance with emerging evidence for injury prediction. PURPOSE: To determine the relationship between injury history, total body flexibility and movement pattern performance in college dance majors. METHODS: Twenty-one, currently injury free, female dance majors (mean age: 18.1 ± 0.74, height: 161.3 ± 5.5 cm, weight: 57.6 ± 8.4 kg), completed the FMS (0-21), a flexibility assessment (Beighton score; 0-9), and an injury history questionnaire. Spearman’s rho (rs) correlations were used to assess the hypotheses that a higher number of dance related injuries and history of LBP would be moderately associated with excessive flexibility (higher Beighton score) and poorer functional movement patterns (lower FMS score). RESULTS: The median and range of the FMS and Beighton scores were: FMS (15, 5-19); Beighton (1, 0-5). The mean number of dance related injuries were 1.8 ± 1.3 (71.8% in the LE). 17 of 21 had a previous LE injury while eight (17.9%) dancers had a history of LBP. There was no relationship between history of LBP and FMS (rs = -.02, p= .94) or Beighton score (rs = .16, p= .48), and the number of dance injuries and Beighton score (rs = .06, p = .78). Beighton and FMS scores were not significantly associated (rs = .27, p =.24). However, a significant and moderate negative association existed between FMS score and number of dance injuries (rs = - .57, p = .007). CONCLUSIONS: Our data suggests that an increased number of previous injuries is associated with poorer movement pattern control in dancers and explains 25% of the variance in the FMS scores. Over 70% of reported injuries were LE and FMS heavily assesses LE movement patterns. Further studies are needed to examine the utility of the FMS for identifying injury risk in dancers.

ARE FORCE ASYMMETRIES MEASURED IN JUMP TESTS ASSOCIATED WITH PREVIOUS INJURY IN PROFESSIONAL FOOTBALLERS?

BackgroundIn female athletes, bilateral aysmmetry in peak landing forces during the drop jump is associated with anterior cruciate ligament (ACL) injury risk and is proposed as a marker of rehabilitation...