Background:
The incidence of second anterior cruciate ligament (ACL) injuries in the first 12 months after ACL reconstruction (ACLR) and return to sport (RTS) in a young, active population has been ...reported to be 15 times greater than that in a previously uninjured cohort. There are no reported estimates of whether this high relative rate of injury continues beyond the first year after RTS and ACLR.
Hypothesis:
The incidence rate of a subsequent ACL injury in the 2 years after ACLR and RTS would be less than the incidence rate reported within the first 12 months after RTS but greater than the ACL injury incidence rate in an uninjured cohort of young athletes.
Study Design:
Cohort study; Level of evidence, 2.
Methods:
Seventy-eight patients (mean age, 17.1 ± 3.1 years) who underwent ACLR and were ready to return to a pivoting/cutting sport and 47 controls (mean age, 17.2 ± 2.6 years) who also participated in pivoting/cutting sports were prospectively enrolled. Each participant was followed for injury and athlete exposure (AE) data for a 24-month period after RTS. Twenty-three ACLR and 4 control participants suffered an ACL injury during this time. Incidence rate ratios (IRRs) were calculated to compare the rates (per 1000 AEs) of ACL injury in athletes in the ACLR and control groups. For the ACLR group, similar comparisons were conducted for side of injury by sex.
Results:
The overall incidence rate of a second ACL injury within 24 months after ACLR and RTS (1.39/1000 AEs) was nearly 6 times greater (IRR, 5.71; 95% CI, 2.0-22.7; P = .0003) than that in healthy control participants (0.24/1000 AEs). The rate of injury within 24 months of RTS for female athletes in the ACLR group was almost 5 times greater (IRR, 4.51; 95% CI, 1.5-18.2; P = .0004) than that for female controls. Although only a trend was observed, female patients within the ACLR group were twice as likely (IRR, 2.43; 95% CI, 0.8-8.6) to suffer a contralateral injury (1.13/1000 AEs) than an ipsilateral injury (0.47/1000 AEs). Overall, 29.5% of athletes suffered a second ACL injury within 24 months of RTS, with 20.5% sustaining a contralateral injury and 9.0% incurring a retear injury of the ipsilateral graft. There was a trend toward a higher proportion of female participants (23.7%) who suffered a contralateral injury compared with male participants (10.5%) (P = .18). Conversely, for ipsilateral injuries, the incidence proportion between female (8.5%) and male (10.5%) participants was similar.
Conclusion:
These data support the hypothesis that in the 24 months after ACLR and RTS, patients are at a greater risk to suffer a subsequent ACL injury compared with young athletes without a history of ACL injuries. In addition, the contralateral limb of female patients appears at greatest risk.
Incidence rate (IR) of an ipsilateral or contralateral injury after anterior cruciate ligament reconstruction (ACLR) is unknown. The hypotheses were that the IR of anterior cruciate ligament (ACL) ...injury after ACLR would be greater than the IR in an uninjured cohort of athletes and would be greater in female athletes after ACLR than male athletes.
Prospective case-control study.
Regional sports community.
Sixty-three subjects who had ACLR and were ready to return to sport (RTS) and 39 control subjects.
Second ACL injury and sex.
Second ACL injury and athletic exposure (AE) was tracked for 12 months after RTS. Sixteen subjects after ACLR and 1 control subject suffered a second ACL injury. Between- and within-group comparisons of second ACL injury rates (per 1000 AEs) were conducted.
The IR of ACL injury after ACLR (1.82/1000 AE) was 15 times greater risk ratio (RR) = 15.24; P = 0.0002) than that of control subjects (0.12/1000 AE). Female ACLR athletes demonstrated 16 times greater rate of injury (RR = 16.02; P = 0.0002) than female control subjects. Female athletes were 4 (RR = 3.65; P = 0.05) times more likely to suffer a second ACL injury and 6 times (RR = 6.21; P = 0.04) more likely to suffer a contralateral injury than male athletes.
An increased rate of second ACL injury after ACLR exists in athletes when compared with a healthy population. Female athletes suffer contralateral ACL injuries at a higher rate than male athletes and seem to suffer contralateral ACL injuries more frequently than graft re-tears. The identification of a high-risk group within a population of ACLR athletes is a critical step to improve outcome after ACLR and RTS.
Background
Athletes who return to sport participation after anterior cruciate ligament reconstruction (ACLR) have a higher risk of a second anterior cruciate ligament injury (either reinjury or ...contralateral injury) compared with non—anterior cruciate ligament— injured athletes.
Hypotheses
Prospective measures of neuromuscular control and postural stability after ACLR will predict relative increased risk for a second anterior cruciate ligament injury.
Study Design
Cohort study (prognosis); Level of evidence, 2.
Methods
Fifty-six athletes underwent a prospective biomechanical screening after ACLR using 3-dimensional motion analysis during a drop vertical jump maneuver and postural stability assessment before return to pivoting and cutting sports. After the initial test session, each subject was followed for 12 months for occurrence of a second anterior cruciate ligament injury. Lower extremity joint kinematics, kinetics, and postural stability were assessed and analyzed. Analysis of variance and logistic regression were used to identify predictors of a second anterior cruciate ligament injury.
Results
Thirteen athletes suffered a subsequent second anterior cruciate ligament injury. Transverse plane hip kinetics and frontal plane knee kinematics during landing, sagittal plane knee moments at landing, and deficits in postural stability predicted a second injury in this population (C statistic = 0.94) with excellent sensitivity (0.92) and specificity (0.88). Specific predictive parameters included an increase in total frontal plane (valgus) movement, greater asymmetry in internal knee extensor moment at initial contact, and a deficit in single-leg postural stability of the involved limb, as measured by the Biodex stability system. Hip rotation moment independently predicted second anterior cruciate ligament injury (C = 0.81) with high sensitivity (0.77) and specificity (0.81).
Conclusion
Altered neuromuscular control of the hip and knee during a dynamic landing task and postural stability deficits after ACLR are predictors of a second anterior cruciate ligament injury after an athlete is released to return to sport.
Background: Range of motion deficits in shoulder external rotation (ER), internal rotation (IR), total rotation range of motion (ER + IR), and horizontal adduction (HA) have been retrospectively ...associated with overhand athletes’ arm injuries.
Hypothesis: The authors expected the incidence of upper extremity injury in high school softball and baseball players with side-to-side shoulder range of motion deficits to be greater than the incidence of upper extremity injury in players with normal shoulder range of motion.
Study Design: Cohort study (prognosis); Level of evidence, 2.
Methods: High school softball and baseball players (N = 246) participated. Before the start of the season, passive shoulder ER, IR, and HA were assessed at 90° of abduction with the scapula stabilized. Relative risk (RR) was calculated to examine range of motion measure, by categorical criteria, and risk of upper extremity injury.
Results: Twenty-seven shoulder and elbow injuries (9 softball, 18 baseball) were observed during the season. The dominant shoulder of all injured players and baseball players displayed a significant decrease in HA (P = .05) and IR (P = .04). The dominant shoulder total rotation of injured baseball players displayed a significant decrease (mean difference = 8.0° ± 0.1°; P = .05) as compared with the dominant shoulder of uninjured baseball players. Players who displayed a decrease of ≥25° of IR in the dominant shoulder were at 4 times greater risk of upper extremity injury compared with players with a <25° decrease in IR, especially for baseball players. While we observed a 1.5 to 2 times increased risk of injury for the 10° to 20° loss in rotational range of motion for the overall sample and baseball, the risk estimates were not statistically significant (P > .05).
Conclusion: There are large mean deficits in shoulder IR and HA between injured and noninjured players, but not in ER or total rotation. Passive shoulder IR loss ≥25° as compared bilaterally was predictive of arm injury. Shoulder range of motion deficits differed between sports and appeared more predictive of injury for baseball players.
Background Approximately 6 million youngsters play organized baseball yearly, and injuries are common. Defining of risk factors for injuries in the throwing shoulder has largely been confined to the ...professional thrower. Unfortunately, these risk factors apply to only 1% of pitchers at risk for injury. Risk factors for injury in youth pitchers have received far less attention than those in more mature professional pitchers. Development of such an understanding would help clarify injury prevention efforts for the other 99% of pitchers actively participating in competitive baseball. This study intended to determine the ability of range of motion (ROM) measures to predict arm injuries in baseball pitchers aged 8 to 18 years. Methods Supine passive shoulder ROM was assessed in 115 pitchers with a digital inclinometer. Two trials of ROM were measured before the season. Arm injuries were prospectively tracked. Receiver operating characteristic curves were used to identify athletes who were at high risk for injury. Statistical significance was set a priori (α = .05). Results There were 33 injured and 82 uninjured pitchers. Side-to-side differences of horizontal adduction >15° and internal rotation >13° may discriminate between those adolescent pitchers at 4 and 6 times greater risk of injury, respectively. Conclusion Preseason ROM differences were able to identify those adolescents at high risk for injury during the season. It appears that the risk profile for adolescent pitchers includes horizontal adduction differences that differ from the established prospective profile in adult pitchers.
Prospective cohort.
To examine the relationship between summer training practices and risk of injury during the first month of a high school interscholastic cross-country season.
Several prospective ...studies have reported a high incidence of injury in adolescent cross-country runners. However, limited reports exist on the role of summer training practices and risk of injury among these runners.
Four hundred twenty-one athletes (186 girls, 235 boys) who competed in interscholastic cross-country were followed during a cross-country season. At the start of the season, all participants completed a questionnaire regarding summer training routines. Time-loss, running-related injuries were tracked during the subsequent season. Logistic regression analysis was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for the risk of initial injury during the first month of the season associated with summer training variables.
Sixty-seven runners (15.9%) had a confirmed injury during the first month of the season, with a higher percent among girls (19.4%) than boys (13.2%) (P = .06). Overall, 60.1% of the participants ran during the summer prior to the season, with a significantly higher percent among girls (71.5%) than boys (51.1%) (P<.0001). Overall, no significant association (OR = 0.9; 95% CI: 0.5, 1.5; P = .90) was found between not running sometime during the preceding summer and increased risk of initial injury during the first month of the season. Among only the runners who ran during the summer, after adjusting for sex and prior injury, first-month injuries were more common among those who did not frequently alternate short and long mileage on different days (OR = 3.0; 95% CI: 1.4, 6.4; P = .005), and/or who ran 8 weeks or fewer (OR = 2.7; 95% CI: 1.2, 5.8; P = .01) during their summer training. Running 8 weeks or fewer (P = .03), not frequently alternating mileage on different days (P = .01), and running a higher percentage of time on predominantly hill (P = .001) and irregular terrains (P = .004) were associated with increased risk of injury for girls.
These findings suggest that injuries during the first month of the high school cross-country season may be reduced if runners who participate in summer training activities run a greater number of weeks and frequently vary their daily running mileage during the summer. For girls, training programs that reduce mileage on hills and irregular terrains may help to minimize the occurrence of running-related injury.
Prognosis, level 1b-.
High school cross-country runners have a high incidence of injury, particularly at the shin and knee. An increased step rate during running has been shown to reduce impact forces and loading of the ...lower extremity joints. The purpose of this prospective study was to examine step rate as a risk factor for injury occurrence.
Running step rates of 68 healthy high school cross-country runners (47 females; 21 males; mean age 16.2 ± 1.3 yr) were assessed at a fixed speed (3.3 ± 0.0 m·s) and self-selected speed (mean, 3.8 ± 0.5 m·s). Runners were prospectively followed during the interscholastic season to determine athletic exposures, occurrences of shin injury and anterior knee pain (AKP), and days lost to injury.
During the season, 19.1% of runners experienced a shin injury and 4.4% experienced AKP. Most injuries (63.6%) were classified as minor (1-7 d lost). At the fixed speed, runners in the lowest tertile of step rate (≤164 steps per minute) were more likely (odds ratio, 6.67; 95% confidence interval, 1.2-36.7; P = 0.03) to experience a shin injury compared with runners in the highest tertile (≥174 steps per minute). Similarly, for self-selected speed, runners in the lowest tertile (≤166 steps per minute) (odds ratio, 5.85; 95% confidence interval, 1.1-32.1; P < 0.04) were more likely to experience a shin injury than runners in the highest tertile (≥178 steps per minute). AKP incidence was not significantly influenced by step rate.
A lower running step rate was associated with a greater likelihood of shin injury at both self-selected and fixed running speeds. Future studies evaluating whether increasing running step rate reduces shin injury risk and time lost during a high school cross-country season should be considered.
Prospective cohort.
To determine if Star Excursion Balance Test (SEBT) reach distance was associated with risk of lower extremity injury among high school basketball players.
Although balance has ...been proposed as a risk factor for sports-related injury, few researchers have used a dynamic balance test to examine this relationship.
Prior to the 2004 basketball season, the anterior, posteromedial, and posterolateral SEBT reach distances and limb lengths of 235 high school basketball players were measured bilaterally. The Athletic Health Care System Daily Injury Report was used to document time loss injuries. After normalizing for lower limb length, each reach distance, right/left reach distance difference, and composite reach distance were examined using odds ratio and logistic regression analyses.
The reliability of the SEBT components ranged from 0.82 to 0.87 (ICC3,1) and was 0.99 for the measurement of limb length. Logistic regression models indicated that players with an anterior right/left reach distance difference greater than 4 cm were 2.5 times more likely to sustain a lower extremity injury (P<.05). Girls with a composite reach distance less than 94.0% of their limb length were 6.5 times more likely to have a lower extremity injury (P<.05).
We found components of the SEBT to be reliable and predictive measures of lower extremity injury in high school basketball players. Our results suggest that the SEBT can be incorporated into preparticipation physical examinations to identify basketball players who are at increased risk for injury.
The purpose of this study was to examine the effects of a 12-wk in-home self-monitored physical activity (PA) program targeting a combination of lifestyle PA program on changes in endothelial ...reactivity, arterial stiffness, sedentary behaviors, and upright and stepping activities in individuals with asymptomatic peripheral arterial disease (APAD).
Participants (n = 38) with APAD (ages 52-87 yr) were randomized to attention control (AC) or a PA sedentary reduction (PASR) group using an interactive online 3-month program focusing on increasing lifestyle PA and decreasing sedentary behaviors. The ActivPal™ PA monitor was used to measure postural and stepping parameters. Endothelial reactivity (peripheral arterial tone-reactive hyperemia index PAT-RHI) and augmentation index (AIx) were measured using the EndoPAT™ system at baseline and 3 months.
The PASR group significantly decreased daily sit/lie hours (-0.80 ± 0.87 vs 0.18 ± 0.77 P = 0.001), increased sit-to-stand transitions per day (7.1 ± 10.5 vs -1.4 ± 5.71, P < 0.001), and increased daily step counts (2814 ± 1753 vs 742 ± 1321, P < 0.001). The PASR group also increased steps per day accumulated within specific cadence bands 61-80 steps per minute (1252 ± 447 vs 177 ± 359, P < 0.001), 81-100 steps per minute band (919 ± 511 vs -98 ± 697, P < 0.001), and within the 101-120 steps per minute band (415 ± 625 vs -327 ± 467, P < 0.001) versus the AC group. PAT-RHI significantly increased in the PASR group (0.179 ± 0.180 vs 0.0.044 ± 0.101, P = 0.019), whereas no significant changes were observed in PAT-AIx.
Modest improvements in microvascular reactivity, PA, sedentary behavior, but not arterial stiffness were demonstrated after a 12-wk intervention targeting sedentary behavior reduction and increased lifestyle PA in individuals with APAD.
Prior authors have reported associations among increased risk of injury and factors of the female athlete triad, as defined before the 2007 American College of Sports Medicine position stand, in ...collegiate and adult club sport populations. Little is known about this relationship in an adolescent competitive sports population.
To examine the relationship among disordered eating, menstrual dysfunction, and low bone mineral density (BMD) and musculoskeletal injury among girls in high school sports.
Prospective cohort study.
The sample consisted of 163 female athletes competing in 8 interscholastic sports in southern California during the 2003-2004 school year. Each participant was followed throughout her respective sport season for occurrence of musculoskeletal injuries.
Data collected included daily injury reports, the Eating Disorder Examination Questionnaire that assessed disordered eating attitudes and behaviors, a dual-energy x-ray absorptiometry scan that measured BMD and lean tissue mass, anthropometric measurements, and a questionnaire on menstrual history and demographic characteristics.
Sixty-one athletes (37.4%) incurred 90 musculoskeletal injuries. In our BMD z score model of <or=-1 SD, a history of oligomenorrhea/amenorrhea during the past year and low BMD (z score <or=-1 SD) were associated with the occurrence of musculoskeletal injury during the interscholastic sport season. In our BMD z score model of <or=-2 SDs, disordered eating (Eating Disorder Examination Questionnaire score >or=4.0), a history of oligomenorrhea/amenorrhea during the past year, and a low BMD (z score <or=-2 SDs) were associated with musculoskeletal injury occurrence.
These findings indicate that disordered eating, oligomenorrhea/amenorrhea, and low BMD were associated with musculoskeletal injuries in these female high school athletes. Programs designed to identify and prevent disordered eating and menstrual dysfunction and to increase bone mass in athletes may help to reduce musculoskeletal injuries.
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