A Refined Prediction Model for Core and Lower Extremity Sprains and Strains Among Collegiate Football Players

Sagittal trunk excursion and lumbar repositioning error between female and male patients with patellofemoral pain syndrome

Background

Patellofemoral pain syndrome (PFPS) is a challenging clinical problem affecting adults, adolescents, and physically active populations. PFPS impacts the patient's trunk kinematics in the frontal plane. Previous studies have found gender-based biomechanical differences in patients with PFPS; however, sagittal trunk kinematics during mini-squats and lumbar proprioception in PFPS have not been studied previously.

Objectives

To investigate sagittal trunk excursion (It is defined as the sagittal trunk flexion angle from the start to the end of the mini squat) during mini-squats as well as lumbar repositioning error between individuals with and without PFPS, and determine gender differences in the outcome variables.

Methods

A sample of 56 participants aged 18-25 years was enrolled; 30 with PFPS (13 males, 17 females) and 26 asymptomatic controls (11 males, 15 females). The sagittal trunk excursion during mini-squats was examined by two-dimensional (2D) photographic analysis using Surgimap software. Active lumbar flexion repositioning error was assessed using an isokinetic dynamometer.

Results

For sagittal trunk excursion, no significant main effect of group was observed (p = 0 . 136 ). On the other hand, the main effect was significant for gender (p = 0 . 005 ), as was the interaction effect. Compared to the control group, the PFPS group showed significantly (p = 0 . 01 ) lower sagittal trunk excursion in females than in males during mini-squats. For active lumbar flexion repositioning error, no evidence was found for significant main or interaction effects (p > 0 . 05 ).

Conclusion

Females with PFPS exhibit a more erect sagittal trunk posture than males during mini-squats. Trunk posture should be considered during weight-bearing activities in PFPS, and gender-specific assessment protocols should be developed.

The Trade Secret Taboo: Open Science Methods are Required to Improve Prediction Models in Sports Medicine and Performance

Clinical prediction models in sports medicine that utilize regression or machine learning techniques have become more widely published, used, and disseminated. However, these models are typically characterized by poor methodology and incomplete reporting, and an inadequate evaluation of performance, leading to unreliable predictions and weak clinical utility within their intended sport population. Before implementation in practice, models require a thorough evaluation. Strong replicable methods and transparency reporting allow practitioners and researchers to make independent judgments as to the model's validity, performance, clinical usefulness, and confidence it will do no harm. However, this is not reflected in the sports medicine literature. As shown in a recent systematic review of models for predicting sports injury models, most were typically characterized by poor methodology, incomplete reporting, and inadequate performance evaluation. Because of constraints imposed by data from individual teams, the development of accurate, reliable, and useful models is highly reliant on external validation. However, a barrier to collaboration is a desire to maintain a competitive advantage; a team's proprietary information is often perceived as high value, and so these 'trade secrets' are frequently guarded. These 'trade secrets' also apply to commercially available models, as developers are unwilling to share proprietary (and potentially profitable) development and validation information. In this Current Opinion, we: (1) argue that open science is essential for improving sport prediction models and (2) critically examine sport prediction models for open science practices.

Physiological and Biomechanical Monitoring in American Football Players: A Scoping Review

American football is the sport with the highest rates of concussion injuries. Biomedical engineering applications may support athletes in monitoring their injuries, evaluating the effectiveness of their equipment, and leading industrial research in this sport. This literature review aims to report on the applications of biomedical engineering research in American football, highlighting the main trends and gaps. The review followed the PRISMA guidelines and gathered a total of 1629 records from PubMed (n = 368), Web of Science (n = 665), and Scopus (n = 596). The records were analyzed, tabulated, and clustered in topics. In total, 112 studies were selected and divided by topic in the biomechanics of concussion (n = 55), biomechanics of footwear (n = 6), biomechanics of sport-related movements (n = 6), the aerodynamics of football and catch (n = 3), injury prediction (n = 8), heat monitoring of physiological parameters (n = 8), and monitoring of the training load (n = 25). The safety of players has fueled most of the research that has led to innovations in helmet and footwear design, as well as improvements in the understanding and prevention of injuries and heat monitoring. The other important motivator for research is the improvement of performance, which has led to the monitoring of training loads and catches, and studies on the aerodynamics of football. The main gaps found in the literature were regarding the monitoring of internal loads and the innovation of shoulder pads.

The effects of core stabilization exercises on the neuromuscular function of athletes with ACL reconstruction

Athletes who have undergone anterior cruciate ligament reconstruction (ACLR) often exhibit persistently impaired kinematics and strength. Core stability training appears to be effective for reducing high-risk landing mechanics and preventing primary anterior cruciate ligament (ACL) injuries; however, there have been few attempts to examine their effects in athletes who have undergone ACLR. This study aimed to investigate the effect of eight weeks of simple core stability training on core endurance, hip strength, and knee kinematics in ACLR athletes. Twenty-six male athletes (20-30 years old) with a history of ACL surgery with hamstring tendon autograft were randomly divided into training (n = 13) and control groups (n = 13). The training group performed core stability exercises for eight weeks before starting their team training; the control group did not receive any intervention. Both groups continued their regular team schedule. The core endurance, hip muscle strength, and knee kinematics were assessed by the McGill test, a hand-held dynamometer, and video-taping, respectively. Analysis of covariance test was used for data analysis. The training group showed a significant increase in core endurance, hip abductor and external rotator strength, knee flexion angle, and a significant decrease in the knee valgus angle during single-leg landing in post-training tests compared to their baseline tests (P < 0.05). Our results demonstrated that core stability exercise alters neuromuscular function to a level that is clinically acceptable and statistically significant. Because of the high incidence rate of secondary ACL injury after ACLR, it is recommended that athletes with a history of ACLR benefit from adding core stability exercises to warm-up routines or tertiary prevention programs even after completing post-operative rehabilitation. It is fast and not time-consuming to perform for athletes to reduce the risk factors of re-injury. Trial registration: This study was registered in the Iranian Registry of Clinical Trials with the number IRCT20190224042827N2, registered on 19 December 2019.

The Running Readiness Scale as an Assessment of Kinematics Related to Knee Injury in Novice Female Runners

CONTEXT

Frontal- and transverse-plane kinematics have been prospectively identified as risk factors for running-related injuries in females. The Running Readiness Scale (RRS) may allow for clinical evaluation of these kinematics.

OBJECTIVES

To determine the reliability and validity of the RRS as an assessment of frontal- and transverse-plane running kinematics.

DESIGN

Cross-sectional study.

SETTING

University research laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 56 novice female runners (median [interquartile range] age = 34 years [26-47 years]).

MAIN OUTCOME MEASURE(S)

We collected 3-dimensional kinematics during running and RRS tasks: hopping, plank, step-ups, single-legged squats, and wall sit. Five clinicians assessed RRS performances 3 times each. Interrater and intrarater reliabilities of the total RRS score and individual tasks were calculated using the intraclass correlation coefficient and Fleiss κ, respectively. Pearson product moment correlation coefficients between peak joint angles measured during running and the same angles measured during RRS tasks were computed. Peak joint angles of high- and low-scoring participants were compared.

RESULTS

Interrater and intrarater reliabilities of assessment of the total RRS scores were good (intraclass correlation coefficients = 0.75 and 0.80, respectively). Reliability of assessing individual tasks was moderate to almost perfect (κ = 0.58-1.00). Peak hip adduction, contralateral pelvic drop, and knee abduction during running were correlated with the same angles measured during hopping, step-ups, and single-legged squats (r = 0.537-0.939). Peak knee internal rotation during running was correlated with peak knee internal rotation during step-ups (r = 0.831). Runners who scored high on the RRS demonstrated less knee abduction during running (P ≤ .01).

CONCLUSIONS

The RRS may effectively assess knee abduction in novice runners, but evaluation criteria or tasks may need to be modified to effectively characterize pelvic and transverse-plane knee kinematics.

Preseason Prognostic Factors for Injuries and Match Loss in Collision Sports: A Systematic Review

This study aimed to identify which preseason factors had strong evidence of risks for physical injury during the season of collision sports including rugby, American football, and Australian rules football using qualitative synthesis. Pubmed, EMBASE, MEDLINE, SPORTDiscus, Scopus, and the Cochrane Library were reviewed. Eligibility criteria for selecting studies were: studies involving the collision sports; prospective cohort studies; and studies with outcomes of relative risks, odds ratios, and correlations between players' preseason conditions and injury during the season. The risk of bias based on the Scottish Intercollegiate Guidelines Network quality checklists for cohort studies was assessed in 57 studies. The current study identified strong evidence that 1) anthropometric characteristics (body mass index and estimated mass moment of inertia of the body around a horizontal axis through the ankle), which are calculated with weight and height; 2) physical function, in particular for the trunk and lower limb (trunk-flexion hold and wall-sit hold); and 3) Oswestry Disability Index disability, which is a patient-reported outcome measure for disability due to low back pain, were positive prognostic factors for injury during the collision sports season, regardless of playing experience.

Just How Confident Can We Be in Predicting Sports Injuries? A Systematic Review of the Methodological Conduct and Performance of Existing Musculoskeletal Injury Prediction Models in Sport

BACKGROUND

An increasing number of musculoskeletal injury prediction models are being developed and implemented in sports medicine. Prediction model quality needs to be evaluated so clinicians can be informed of their potential usefulness.

OBJECTIVE

To evaluate the methodological conduct and completeness of reporting of musculoskeletal injury prediction models in sport.

METHODS

A systematic review was performed from inception to June 2021. Studies were included if they: (1) predicted sport injury; (2) used regression, machine learning, or deep learning models; (3) were written in English; (4) were peer reviewed.

RESULTS

Thirty studies (204 models) were included; 60% of studies utilized only regression methods, 13% only machine learning, and 27% both regression and machine learning approaches. All studies developed a prediction model and no studies externally validated a prediction model. Two percent of models (7% of studies) were low risk of bias and 98% of models (93% of studies) were high or unclear risk of bias. Three studies (10%) performed an a priori sample size calculation; 14 (47%) performed internal validation. Nineteen studies (63%) reported discrimination and two (7%) reported calibration. Four studies (13%) reported model equations for statistical predictions and no machine learning studies reported code or hyperparameters.

CONCLUSION

Existing sport musculoskeletal injury prediction models were poorly developed and have a high risk of bias. No models could be recommended for use in practice. The majority of models were developed with small sample sizes, had inadequate assessment of model performance, and were poorly reported. To create clinically useful sports musculoskeletal injury prediction models, considerable improvements in methodology and reporting are urgently required.

Plank Times and Lower Extremity Overuse Injury in Collegiate Track-and-Field and Cross Country Athletes

Trunk muscle endurance has been theorized to play a role in running kinematics and lower extremity injury. However, the evidence examining the relationships between static trunk endurance tests, such as plank tests, and lower extremity injury in athletes is conflicting. The purpose of this study was to assess if collegiate cross country and track-and-field athletes with shorter pre-season prone and side plank hold times would have a higher incidence of lower extremity time-loss overuse injury during their competitive sport seasons. During the first week of their competitive season, 75 NCAA Division III uninjured collegiate cross country and track-and-field athletes (52% female; mean age 20.0 ± 1.3 years) performed three trunk endurance plank tests. Hold times for prone plank (PP), right-side plank (RSP) and left-side plank (LSP) were recorded in seconds. Athletes were followed prospectively during the season for lower extremity overuse injury that resulted in limited or missed practices or competitions. Among the athletes, 25 (33.3%) experienced a lower extremity overuse injury. There were no statistically significant mean differences or associations found between PP, RSP or LSP plank test hold times (seconds) and occurrence of lower extremity overuse injury. In isolation, plank hold times appear to have limited utility as a screening test in collegiate track-and-field and cross country athletes.

The effects of visual cognitive tasks on landing stability and lower extremity injury risk in high-level soccer players

BACKGROUND

Visual cognition plays a pivotal role in sports. It is widely recognized that there is an intriguing coupling that they could affect each other through interaction between visual cognition and motor control, but few studies linked the effects of visual cognitive tasks on landing stability to postural control and injury risk.

RESEARCH QUESTION

Whether visual cognitive tasks affect the landing stability and lower limb injury risk of professional soccer players?

METHODS

The current study used a three-dimensional Multiple Object Tracking (MOT) task to simulate visual cognitive difficulties experienced in soccer matches. Fifteen male high-level soccer athletes (height: 181.43 ± 7.36 cm, weight: 75.37 ± 10.67 kg, training years: 10.07 ± 2.98 yr) from our school team were recruited and completed a landing action from a high platform with and without MOT tasks. Vicon infrared high-speed motion capture system and three-dimensional force measuring platform were used to collect various outcomes simultaneously.

RESULTS

The Time to Stabilization (TTS) during landing was significantly prolonged, while the Medial-Lateral Stability Index (MLSI), Anterior-Posterior Stability (APSI), Dynamic Postural Index Stability Index (DPSI), the trajectory lengths, and envelope area of COP during landing were also increased during MOT dual-task.

DISCUSSION

The decline of these indicators reflected the deterioration in postural stability and greater requirements for maintaining balance which could increase the risk of injury in soccer athletes. We advocate that adequate visual attention and visual information processing might play critical roles in maintaining dynamic balance through the supraspinal neural network.

Whole-Body Reactive Agility Metrics to Identify Football Players With a Core and Lower Extremity Injury Risk

Clinical prediction models are useful in addressing several orthopedic conditions with various cohorts. American football provides a good population for attempting to predict injuries due to their relatively high injury rate. Physical performance can be assessed a variety of ways using an assortment of different tests to assess a diverse set of metrics, which may include reaction time, speed, acceleration, and deceleration. Asymmetry, the difference between right and left performance has been identified as a possible risk factor for injury. The purpose of this study was to determine the whole-body reactive agility metrics that would identify Division I football players who were at elevated risk for core, and lower extremity injuries (CLEI). This cohort study utilized 177 Division I football players with a total of 57 CLEI suffered who were baseline tested prior to the season. Single-task and dual-task whole-body reactive agility movements in lateral and diagonal direction reacting to virtual reality targets were analyzed separately. Receiver operator characteristic (ROC) analyses narrowed the 34 original predictor variables to five variables. Logistic regression analysis determined the three strongest predictors of CLEI for this cohort to be: lateral agility acceleration asymmetry, lateral flanker deceleration asymmetry, and diagonal agility reaction time average. Univariable analysis found odds ratios to range from 1.98 to 2.75 for these predictors of CLEI. ROC analysis had an area under the curve of 0.702 for any combination of two or more risk factors produced an odds ratio of 5.5 for risk of CLEI. These results suggest an asymmetry of 8-15% on two of the identified metrics or a slowed reaction time of ≥0.787 s places someone at increased risk of injury. Sixty-three percent (36/57) of the players who sustained an injury had ≥2 positive predictors In spite of the recognized limitation, these finding support the belief that whole-body reactive agility performance can identify Division I football players who are at elevated risk for CLEI.

Association of Functional Movement Screen and Y-Balance Test Scores With Injury in High School Athletes

ABSTRACT

Lisman, P, Hildebrand, E, Nadelen, M, and Leppert, K. Association of functional movement screen and Y-Balance Test scores with injury in high school athletes. J Strength Cond Res 35(7): 1930-1938, 2021-The purpose of this study was to determine the association between functional movement screen (FMS) and Y-Balance Test (YBT) performance and lower extremity injury in a sample of male high school athletes. A total of 124 high school football (n = 89), lacrosse (n = 25), and baseball (n = 10) players underwent FMS and YBT before the start of their competitive seasons. Time loss lower extremity injury incidence data were tracked by each team's certified athletic trainer and used for analysis. Receiver operating characteristic (ROC) curves were calculated to determine the optimal cutpoints for FMS composite score (CS) and YBT measures, including CS and reach distance asymmetry for anterior, posteromedial, and posterolateral directions, for predicting injury. No cutpoints on the ROC curves maximized sensitivity and specificity; therefore, FMS CS and YBT measures (CS and asymmetry) were analyzed as continuous variables. Logistic regression models adjusted for age and sport revealed no significant associations between FMS CS and lower extremity injury (odds ratio [OR] = 0.99; 95% confidence interval [CI] = 0.83-1.20). Similar findings were found for YBT asymmetry in all directions (ORs ranged from 0.98 to 1.08) and CS (OR = 0.99; 95% CI = 0.95-1.04). There were also no significant associations between the presence of asymmetry and low score (score of 1) on any individual FMS test and injury. Overall, FMS and YBT were not associated with increased risk of lower extremity injury in this sample of high school athletes. These findings do not support the use of FMS and YBT as stand-alone injury risk assessments in high school athletes.

The Relationship Between Hip Strength and Postural Stability in Collegiate Athletes Who Participate in Lower Extremity Dominant Sports

BACKGROUND

Lower extremity (LE) injuries are common across many sports. Both core strength (including hip strength) deficits and poor postural stability have been linked to lower extremity (LE) injury. The relationship between these two characteristics is unknown.

PURPOSE

To explore the relationships between hip strength, static postural stability, and dynamic postural stability.

STUDY DESIGN

Descriptive Cross-Sectional Study.

METHODS

162 Division I student-athletes (111 males and 51 females) participated in this study. Isometric hip strength was measured using a hand-held dynamometer and both single-leg static (eyes open EO and eyes closed EC) and dynamic postural stability were assessed with a force plate. Pairwise correlations were calculated to examine the relationship between the hip strength variables and the postural stability scores for all subjects and separately for males and females.

RESULTS

There were no significant correlations between hip strength and dynamic postural stability for any of the pairwise correlations. Significant, albeit minimal, correlations between EO and EC static postural stability and each of the hip strength variables for all subjects and male subjects (correlation coefficients ranged from -0.19 to -0.34). However, there were only two significant correlations between hip strength and EC static postural stability (hip internal/external rotation) and one for hip strength and EO postural stability (hip internal rotation) found for female subjects (correlation coefficients ranged from -0.28 to -0.31).

CONCLUSION

There was no relationship between isometric hip strength and dynamic postural stability; whereas, there were some relationships between the strength measures and static postural stability. These significant, but minimal correlations were observed in more of the comparisons within the male cohort potentially demonstrating a sex difference.

LEVEL OF EVIDENCE

3b.

Trunk Muscle Endurance in Individuals With and Without a History of Anterior Cruciate Ligament Reconstruction

ABSTRACT

Werner, DM and Barrios, JA. Trunk muscle endurance in individuals with and without a history of anterior cruciate ligament reconstruction. J Strength Cond Res 35(1): 118-123, 2021-Anterior cruciate ligament (ACL) rupture is one of the most common knee injuries and often leads to surgery. Second injury after an ACL reconstruction (ACLR) is a major risk after rehabilitation, and may be linked to persistent postoperative deficits in muscular strength and endurance. Trunk muscle endurance has not been well studied after ACLR. Therefore, the purpose of this study was to compare trunk endurance using the established McGill testing battery in 20 individuals who had previously undergone ACLR at least 1 year before with 20 controls matched for sex frequency, limb dominance, age, body mass index, and activity level. Four static positional holds to failure were performed in random order, with time in seconds recorded as the primary dependent variable. Mann-Whitney U tests using an alpha level of 0.05 were conducted comparing hold times for all positions between groups. Effect sizes were also calculated between groups. Deficits in trunk extension endurance were observed in the surgical group. The results of this study suggest that contemporary rehabilitation schemes after ACLR do not fully address trunk endurance deficits. Health care professionals delivering postoperative rehabilitation after ACLR may consider direct assessment of trunk endurance and targeted exercise training to address potential deficits.

Limited Support for Trunk and Hip Deficits as Risk Factors for Athletic Knee Injuries: A Systematic Review With Meta-analysis and Best-Evidence Synthesis

OBJECTIVE

To determine whether neuromuscular deficits in trunk and hip-related function are risk factors for athletic knee injuries.

DESIGN

Etiology systematic review with meta-analysis.

LITERATURE SEARCH

Six online databases (MEDLINE, Web of Science, Embase, CINAHL, Scopus, and SPORTDiscus) were searched up to April 2019.

STUDY SELECTION CRITERIA

Studies assessing trunk and hip neuromuscular function as risk factors for knee injuries in healthy athletic populations were included.

DATA SYNTHESIS

Outcomes were synthesized quantitatively using meta-analysis of odds ratios, and qualitatively using best-evidence synthesis.

RESULTS

Twenty-one studies met the inclusion criteria. There was very low-certainty evidence that greater hip external rotation strength protected against knee injuries (odds ratio = 0.78; 95% confidence interval: 0.70, 0.87; P<.05). There was limited evidence that deficits in trunk proprioception and neuromuscular control, and the combination of excessive knee valgus and ipsilateral trunk angle when landing unilaterally from a jump, may be risk factors for knee injuries.

CONCLUSION

Most variables of trunk and hip function were not risk factors for injuries. Further research is required to confirm whether hip external rotation strength, trunk proprioception and neuromuscular control, and the combination of knee valgus angle and ipsilateral trunk control are risk factors for future knee injuries. J Orthop Sports Phys Ther 2020;50(9):476-489. Epub 1 Aug 2020. doi:10.2519/jospt.2020.9705.

Y-Balance Test Performance Does Not Determine Non-Contact Lower Quadrant Injury in Collegiate American Football Players

Collegiate American football has a high rate of injury. The Lower Quarter Y-Balance Test (YBT-LQ), a dynamic assessment of lower extremity strength, mobility, and balance, has been purported to identify athletes at risk for injury in different sports including football. Previous studies examining the association between YBT-LQ and injury have reported varied findings; therefore, the purpose of this study was to assess if preseason YBT-LQ performance predicted whether football players would sustain a non-contact lower extremity or low back (lower quarter (LQ)) injury during the season. Fifty-nine male collegiate American football players (age 20.8 ± 1.3 y, height 1.8 ± 0.1 m, body mass 94.6 ± 14.2 kg) completed a survey of training and injury history and had their YBT-LQ performance assessed at the start of the season. Athletic training staff tracked the occurrence of non-contact LQ injuries during the season. There were no significant relationships found between preseason YBT-LQ values and incidence of non-contact LQ injury in this population of collegiate American football players. This study is consistent with recent reports that have not found a significant association between preseason YBT-LQ values and LQ injury. These results suggest that, in isolation, the YBT-LQ may have limited utility as a screening test for non-contact injury in collegiate football players.

Landing Stiffness Between Individuals With and Without a History of Low Back Pain

CONTEXT

Reduced spinal stabilization, delayed onset of muscle activation, and increased knee joint stiffness have been reported in individuals with a history of low back pain (LBP). Biomechanical adaptations resulting from LBP may increase the risk for future injury due to suboptimal loading of the lower-extremity or lumbar spine. Assessing landing mechanics in these individuals could help identify which structures might be susceptible to future injury.

OBJECTIVE

To compare vertical and joint stiffness of the lower-extremity and lumbar spine between individuals with and without a previous history of LBP.

DESIGN

Cross-sectional study.

SETTING

Research laboratory.

PARTICIPANTS

There were 45 participants (24 without a previous history of LBP-age 23 [8] y, height 169.0 [8.5] cm, mass 69.8 [13.8] kg; 21 with a previous history of LBP-age 25[9] y, height 170.0 [8.0] cm, mass 70.2 [11.8] kg).

INTERVENTIONS

Single-limb landing trials on the dominant and nondominant limb from a 30-cm box.

MAIN OUTCOME MEASURES

Vertical stiffness and joint stiffness of the ankle, knee, hip, and lumbar spine.

RESULTS

Individuals with a previous history of LBP had lower vertical stiffness (P = .04), but not joint stiffness measures compared with those without a previous history of LBP (P > .05). Overall females had lower vertical (P = .01), ankle (P = .02), and hip stiffness (P = .04) compared with males among all participants. Males with a previous history of LBP had lower vertical stiffness compared with males without a previous history LBP (P = .01). Among all individuals without a previous history of LBP, females had lower vertical (P < .01) and ankle stiffness measures (P = .04) compared with males.

CONCLUSIONS

Landing stiffness may differ among males and females and a previous history of LBP. Comparisons between individuals with and without previous LBP should be considered when assessing landing strategies, and future research should focus on how LBP impacts landing mechanics.

A COMPARATIVE STUDY OF CORE MUSCULATURE ENDURANCE AND STRENGTH BETWEEN SOCCER PLAYERS WITH AND WITHOUT LOWER EXTREMITY SPRAIN AND STRAIN INJURY

BACKGROUND

Lower extremity sprain and strain injury constitutes a large percentage of lower extremity injuries experienced by soccer players. Yet, very limited data exists on the association between core strength and endurance and this injury.

PURPOSE

The purpose of this study was to compare core muscle endurance and hip muscle strength between soccer players who experienced non-contact lower extremity sprain and/or strain injury during their season and those who did not. Additionally, the frequency of injury was correlated with core muscle endurance and hip strength, and endurance was used for predicting the risk for injury.

STUDY DESIGN

Prospective cohort.

METHODS

Twenty-one (35.59%) athletes experienced non-contact lower extremity sprain and/or strain injury during the season. Fifty-nine male athletes (mean age 20.92 ± 4.08 years, mass 77.34 ± 12.02 kg and height 1.79 ± 0.06m) were tested. Prior to the start of the season, prone-bridge, side-bridge, trunk flexion and horizontal back extension hold times were recorded for endurance assessment and peak hip abductor and external rotator isokinetic torques for strength assessment.

RESULTS

Prone-bridge and side-bridge hold times were significantly longer in the non-injured players when compared with the times of the injured players (p=0.043 & 0.008 for the prone-bridge and side-bridge, respectively). There were significant negative correlations between the frequency of injury and both prone-bridge (r=-0.324, p=0.007) and side-bridge (r=-0.385, p=0.003) hold times. Logistic regression analysis revealed that side-bridge hold time was a significant predictor of injury (OR=0.956, CI=0.925-0.989).

CONCLUSION

Soccer players with non-contact lower extremity sprain and/or strain have less core endurance than non-injured players. Reduced core endurance is associated with increased incidence of injury. Improving side-bridge hold time, specifically, may reduce the risk for injury.

LEVEL OF EVIDENCE

1b.

Lower Back Injuries in National Collegiate Athletic Association Football Players: A 5-Season Epidemiological Study

Background:

Low back injuries are common in collegiate football players and can frequently lead to persistent pain, reinjuries, and time lost from participation.

Purpose:

To describe the epidemiology of back injuries in National Collegiate Athletic Association (NCAA) football players during the 2009/2010 through 2013/2014 academic years utilizing the NCAA Injury Surveillance Program (ISP) database.

Study Design:

Descriptive epidemiology study.

Methods:

A convenience sample of NCAA varsity football teams was utilized to determine the rates and patterns of back injuries as well as to generate national injury estimates. The rates and distribution of back injuries were identified within the context of mechanism of injury, injury chronicity, and time lost from sport. Injury rates were calculated as the number of injuries divided by the total number of athlete-exposures (AEs). Incidence rate ratios were calculated to compare the rates of injury between season, event type, mechanism of injury, injury chronicity, and time lost from sport.

Results:

Nationally, there were 267 low back injuries reported in the database. These were used to estimate 7076 back injuries over the 5-year period, approximately 82% of which were new injuries. The injuries occurred at a rate of 2.70 per 10,000 AEs. Overall, injuries were 3.12 times more likely to occur in competitions than in practices. Athletes were 4.67 times more likely to sustain a back injury during the preseason compared with the postseason but were 1.41 times more likely to sustain a low back injury during the preseason compared with the regular season. Both contact and noncontact were reported equally as the mechanism of injury (37.8% and 38.3%, respectively), and unspecified low back pain was the most common injury (64.2%). Only 1.6% of patients required surgery for their injury, and the majority of athletes (59.6%) returned to play within 24 hours.

Conclusion:

There was a relatively high rate of lumbar back injuries at the collegiate level (2.70/10,000 AEs), the majority of which were new injuries. About 18% of reported injuries were reinjuries. Although very few required surgery, a careful examination and work-up should be conducted to evaluate each injury. Regimented physical therapy and reconditioning programs are recommended to avert reinjuries.

Risk Factors for Initial and Subsequent Core or Lower Extremity Sprain or Strain Among Collegiate Football Players

CONTEXT

Exposure to game conditions and previous injury are known to increase the risk of injury, but little available evidence pertains to modifiable factors that may mediate dynamic control of body segments, such as core muscle endurance and neurocognitive capabilities.

OBJECTIVE

To identify potentially modifiable factors associated with the occurrence of a core or lower extremity sprain or strain during participation in football.

DESIGN

Prospective cohort study.

SETTING

National Collegiate Athletic Association Division I Football Bowl Subdivision football program.

PATIENTS OR OTHER PARTICIPANTS

All team members who participated for the duration of 1 season or both of 2 consecutive seasons (n = 142).

MAIN OUTCOME MEASURE(S)

Predictors of injury occurrence were derived from analysis of preparticipation data that included the results of front plank hold (FPH) and neurocognitive tests. Receiver operating characteristic analysis was used to establish binary classifications of injury risk. Logistic regression analyses were conducted to build multivariable injury-prediction models for optimal discriminatory power.

RESULTS

Exceptionally good discrimination between injured and noninjured participants was provided by models that included the results of the FPH and ImPACT neurocognitive tests. A high level of exposure to game conditions and injury during the preceding year magnified the effects of other risk factors. A model for identifying players with an elevated risk for injury occurrence during both of 2 consecutive seasons included FPH ≤120 seconds, verbal memory score ≤87, composite reaction time ≥560 milliseconds, and starter status. Having ≥2 of the 4 risk factors demonstrated 44% sensitivity and 91% specificity, with an odds ratio = 8.40.

CONCLUSIONS

Core muscle endurance and neurocognitive processes may both play important roles in generating anticipatory muscle stiffness during participation in collegiate football. These factors may be particularly important for players who sustained an injury during the previous year and those who have a high level of game exposure.

Methods for Prediction of Core or Lower Extremity Injury Among High School Football Players as a Strategy for Longitudinal Reduction of Injury Risk

Poor neuromechanical control and rapid fatigue of the core muscles are associated with elevated risk for core or lower extremity (CLE) injury. The purpose of this study was to identify preparticipation screening measures associated with both previous and subsequent CLE injuries among high school football players. Self-reported CLE injury history, core muscle endurance, and postural balance were strongly associated with CLE injury. Our findings demonstrated that the same risk categorization cut-points predicted both injury within the previous 12 months and subsequent season injury. Preseason screening results can be used to estimate CLE injury susceptibility among high school football players.

Strength training as superior, dose-dependent and safe prevention of acute and overuse sports injuries: a systematic review, qualitative analysis and meta-analysis

Objective

This review aims to analyse strength training-based sports injury prevention randomised controlled trials (RCT) and present best evidence recommendations for athletes and future research. A priori PROSPERO registration; CRD42015006970.

Design

Systematic review, qualitative analysis and meta-analysis. Sorting of studies and quality assessments were performed by two independent authors. Qualitative analyses, relative risk (RR) estimate with robustness and strength of evidence tests, formal tests of publication bias and post-hoc meta-regression were performed.

Data sources

PubMed, Embase, Web of Science and SPORTDiscus were searched to July 2017.

Eligibility criteria for selecting studies

RCTs on strength training exercises as primary prevention of sports injuries.

Results

Six studies analysed five different interventions with four distinct outcomes. 7738 participants aged 12–40 years were included and sustained 177 acute or overuse injuries. Studies were published in 2003–2016, five from Europe and one from Africa. Cluster-adjusted intention-to-treat analysis established RR 0.338 (0.238–0.480). The result was consistent across robustness tests and strength of evidence was high. A 10% increase in strength training volume reduced the risk of injury by more than four percentage points. Formal tests found no publication bias.

Conclusion

The included studies were generally well designed and executed, had high compliance rates, were safe, and attained consistently favourable results across four different acute and overuse injury outcomes despite considerable differences in populations and interventions. Increasing strength training volume and intensity were associated with sports injury risk reduction. Three characteristically different approaches to prevention mechanisms were identified and incorporated into contemporary strength training recommendations.

The First Decade of Web-Based Sports Injury Surveillance: Descriptive Epidemiology of Injuries in United States High School Football (2005-2006 Through 2013-2014) and National Collegiate Athletic Association Football (2004-2005 Through 2013-2014)

CONTEXT:

The advent of Web-based sports injury surveillance via programs such as the High School Reporting Information Online system and the National Collegiate Athletic Association Injury Surveillance Program has aided the acquisition of football injury data.

OBJECTIVE:

To describe the epidemiology of injuries sustained in high school football in the 2005-2006 through 2013-2014 academic years and collegiate football in the 2004-2005 through 2013-2014 academic years using Web-based sports injury surveillance.

DESIGN:

Descriptive epidemiology study.

SETTING:

Online injury surveillance from football teams of high school boys (annual average = 100) and collegiate men (annual average = 43).

PATIENTS OR OTHER PARTICIPANTS:

Football players who participated in practices and competitions during the 2005-2006 through 2013-2014 academic years in high school or the 2004-2005 through 2013-2014 academic years in college.

MAIN OUTCOME MEASURE(S):

Athletic trainers collected time-loss injury (≥24 hours) and exposure data. Injury rates per 1000 athlete-exposures (AEs), injury rate ratios (IRRs) with 95% confidence intervals (CIs), and injury proportions by body site and diagnosis were calculated.

RESULTS:

The High School Reporting Information Online system documented 18 189 time-loss injuries during 4 539 636 AEs; the National Collegiate Athletic Association Injury Surveillance Program documented 22 766 time-loss injuries during 3 121  476 AEs. The injury rate was higher among collegiate than high school (7.29 versus 4.01/1000 AEs; IRR = 1.82; 95% CI = 1.79, 1.86) athletes. Most injuries occurred during competitions in high school (53.2%) and practices in college (60.9%). The competition injury rate was higher than the practice injury rate among both high school (IRR = 5.62; 95% CI = 5.46, 5.78) and collegiate (IRR = 6.59; 95% CI = 6.41, 6.76) players. Most injuries at both levels affected the lower extremity and the shoulder/clavicle and were diagnosed as ligament sprains and muscle/tendon strains. However, concussion was a common injury during competitions among most positions.

CONCLUSIONS:

Injury rates were higher in college than in high school and higher for competitions than for practices. Concussion was a frequent injury sustained during competitions, which confirms the need to develop interventions to mitigate its incidence and severity.

THE MUSCULOSKELETAL READINESS SCREENING TOOL- ATHLETE CONCERN FOR INJURY & PRIOR INJURY ASSOCIATED WITH FUTURE INJURY

BACKGROUND

The Musculoskeletal Readiness Screening Tool (MRST) was developed in an effort to consistently predict injury among military personnel. Current injury prediction tools have not consistently predicted injury in this population. The MRST is comprised of the weight bearing forward lunge, modified deep squat, closed kinetic chain upper extremity stability test (CKCUEST), forward step down with eyes closed, stationary tuck jump, unilateral wall sit hold, and subjective, individual perceived level of risk for injury. The Feagin hop and self-reported history of injury were also included in this study protocol. The Feagin hop was a functional test used consistently by the orthopedic department located at the testing site as well as used in a recent study aimed at defining a return to duty screen; self-reported history of injury has been identified as a potential predictor of injury.

PURPOSE

To examine whether MRST scores, as a composite as individual components, were predictive of a United States Military Academy Preparatory School (USMAPS) student athlete sustaining a future musculoskeletal injury.

STUDY DESIGN

Prospective Cohort Study.

METHODS

MRST scores were collected for 141 student athletes (mean age 18.63 ± 1.31) at USMAPS. The injury surveillance period was nine months. Students participated in regularly occurring military specific training and various sports. Mean scores were compared between injured and uninjured groups; binary logistic regression model was also completed.

RESULTS

Seventy students sustained an injury. The top activities resulting in injury included football (36%) and basketball (11%) with injuries predominantly located in the lower extremity including the knee (24%), hip (15%), and ankle (14%). Composite MRST scores were not statistically different between injured (12.58 ± 2.16) and uninjured (13 ± 2.27) groups. There was an association between those with a personal concern for future injury and actual injury (p = .04). There was an association between those reporting a prior injury in the preceding 12 months and those incurring an injury at USMAPS (p = .04).

CONCLUSION

The MRST composite scores were not predictive of injury in this population. Previous injury and personal concern for injury were significant injury predictors.

LEVEL OF EVIDENCE

2a.

A risk assessment model for chronic ankle instability: indications for early surgical treatment? An observational prospective cohort - study protocol

BACKGROUND

Chronic ankle instability (CAI) is a common result of an ankle sprain. Even though early surgical treatment yields the best results, overall only professional athletes are eligible for acute surgical stabilization. Treating all patients with early surgical stabilization leads to a high amount of unnecessary invasive interventions, as not all patients progress to CAI. If patients at risk of developing CAI can be identified, treatment policies may be applied more effectively and efficiently. The purpose of this study is to develop a risk assessment model to identify patients at risk for CAI that should receive early surgical treatment.

METHODS

In this observational prospective cohort, all patients aged sixteen years and older, reporting at the emergency department of one of the participating hospitals after sustaining a lateral ankle sprain, and filled out 1 out of 3 follow-up questionnaires and the 1 year follow-up are included. A lateral and anteroposterior radiograph is made. Patients are excluded if a fracture or other pathology is present. The included patients receive four questionnaires, including questions focusing on the sprain, treatment and complaints, the Foot and Ankle Outcome Score and the Cumberland Ankle Instability Tool. A total of eleven radiographic variables are assessed for inter- and intra-observer reliability. Additionally, four factors extracted from the questionnaires, will be evaluated for correlation with CAI. Significantly correlating factors (e.a. risk factors) will be implemented in a risk assessment model. For the final model, based on sixteen variables with a minimum of 20 events per variable and a prevalence of 30-40% after an initial sprain, a sample size of 2370 patients is needed to perform both internal and external model validation.

DISCUSSION

This study will develop the first large scale model for the risk at CAI after an ankle sprain combining radiographic and patient characteristics. With this risk assessment model, patients at risk for CAI may be identified and properly informed on the treatment options. Patients identified as being at risk, may receive more adequate follow-up and become eligible for early surgical stabilization. This prevents patients from experiencing unnecessary long-lasting complaints, increasing the success rate of conservative and surgical treatment.

TRIAL REGISTRATION

Retrospectively registered: NCT02955485 [Registration date: 3-11-2016]. NTR6139 [Registration date: 3-1-2017].

Changes in Muscle Thickness Across Positions on Ultrasound Imaging in Participants With or Without a History of Low Back Pain

CONTEXT

  Injury-prediction models have identified trunk muscle function as an identifiable factor for future injury. A history of low back pain (HxLBP) may also place athletes at increased risk for future low back pain. Reduced muscle thickness of the lumbar multifidus (LM) and transversus abdominis (TrA) has been reported among populations with clinical low back pain via ultrasound imaging in multiple positions. However, the roles of the LM and TrA in a more functional cohort and for injury prediction are still unknown.

OBJECTIVES

  To (1) assess the reliability of LM and TrA ultrasound measures, (2) compare changes in muscle thickness across positions between persons reporting or not reporting HxLBP, and (3) determine the ability to distinguish between groups.

DESIGN

  Cross-sectional study.

SETTING

  Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

  Participants were 34 people who did not report HxLBP (age = 22 ± 7 years, body mass index = 23.7 ± 2.7) and 25 people who reported HxLBP (age = 25 ± 10 years, body mass index = 24.0 ± 3.2).

MAIN OUTCOME MEASURE(S)

  Muscle thickness and changes in muscle thickness of the LM and TrA as shown on ultrasound imaging.

RESULTS

  Intraclass correlation coefficients ranged from 0.641 to 0.943 for all thickness measures and from 0 to 0.693 for all averaged thickness modulations bilaterally. Participants who reported HxLBP had voluntarily reduced TrA thickness modulations compared with those not reporting HxLBP ( P = .03), and the testing position influenced TrA thickness modulations ( P < .01). No differences were observed for LM thickness modulations between groups or positions ( P > .05). A tabletop cutoff value of 1.32 had a sensitivity of 0.640 and a specificity of 0.706, whereas a seated cutoff value of 1.18 had a sensitivity of 0.600 and a specificity of 0.647.

CONCLUSIONS

  In participants reporting HxLBP, TrA thickness modulations were lower and both tabletop and seated thickness modulations were able to distinguish reported HxLBP status. These findings suggest that TrA muscle function may be altered by HxLBP.

PRESEASON LOWER EXTREMITY FUNCTIONAL TEST SCORES ARE NOT ASSOCIATED WITH LOWER QUADRANT INJURY - A VALIDATION STUDY WITH NORMATIVE DATA ON 395 DIVISION III ATHLETES

BACKGROUND

Preseason performance on the lower extremity functional test (LEFT), a timed series of agility drills, has been previously reported to be associated with future risk of lower quadrant (LQ = low back and lower extremities) injury in Division III (D III) athletes. Validation studies are warranted to confirm or refute initial findings.

HYPOTHESIS/PURPOSE

The primary purpose of this study was to examine the ability of the LEFT to discriminate injury occurrence in D III athletes, in order to validate or refute prior findings. It was hypothesized that female and male D III athletes slower at completion of the LEFT would be at a greater risk for a non-contact time-loss injury during sport. Secondary purposes of this study are to report other potential risk factors based on athlete demographics and to present normative LEFT data based on sport participation.

METHODS

Two hundred and six (females = 104; males = 102) D III collegiate athletes formed a validation sample. Athletes in the validation sample completed a demographic questionnaire and performed the LEFT at the start of their sports preseason. Athletic trainers tracked non-contact time-loss LQ injuries during the season. A secondary analysis of risk based on preseason LEFT performance was conducted for a sample (n = 395) that consisted of subjects in the validation sample (n = 206) as well as athletes from a prior LEFT related study (n = 189).

STUDY DESIGN

Prospective cohort.

RESULTS

Male athletes in the validation sample completed the LEFT [98.6 ( ± 8.1) seconds] significantly faster than female athletes [113.1 ( ± 10.4) seconds]. Male athletes, by sport, also completed the LEFT significantly faster than their female counterparts who participated in the same sport. There was no association between preseason LEFT performance and subsequent injury, by sex, in either the validation sample or the combined sample. Females who reported starting primary sport participation by age 10 were two times (OR = 2.4, 95% CI: 1.2, 4.9; p = 0.01) more likely to experience a non-contact time-loss LQ injury than female athletes who started their primary sport at age 11 or older. Males who reported greater than three hours per week of plyometric training during the six-week period prior to the start of the preseason were four times more likely (OR = 4.0, 95% CI: 1.1, 14.0; p = 0.03) to experience a foot or ankle injury than male athletes who performed three or less hours per week.

CONCLUSIONS

The LEFT could not be validated as a preseason performance measure to predict future sports injury risk. The data presented in this study may aid rehabilitation professionals when evaluating an injured athlete's ability to return to sport by comparing their LEFT score to population norms.

LEVEL OF EVIDENCE

2.

Poor anaerobic power/capability and static balance predicted prospective musculoskeletal injuries among Soldiers of the 101st Airborne (Air Assault) Division

Musculoskeletal injuries have negatively impacted tactical readiness. The identification of prospective and modifiable risk factors of preventable musculoskeletal injuries can guide specific injury prevention strategies for Soldiers and health care providers.

OBJECTIVES

To analyze physiological and neuromuscular characteristics as predictors of preventable musculoskeletal injuries.

DESIGN

Prospective-cohort study.

METHODS

A total of 491 Soldiers were enrolled and participated in the baseline laboratory testing, including body composition, aerobic capacity, anaerobic power/capacity, muscular strength, flexibility, static balance, and landing biomechanics. After reviewing their medical charts, 275 male Soldiers who met the criteria were divided into two groups: with injuries (INJ) and no injuries (NOI). Simple and multiple logistic regression analyses were used to calculate the odds ratio (OR) and significant predictors of musculoskeletal injuries (p<0.05).

RESULTS

The final multiple logistic regression model included the static balance with eyes-closed and peak anaerobic power as predictors of future injuries (p<0.001).

CONCLUSIONS

The current results highlighted the importance of anaerobic power/capacity and static balance. High intensity training and balance exercise should be incorporated in their physical training as countermeasures.

Star Excursion Balance Test Anterior Asymmetry Is Associated With Injury Status in Division I Collegiate Athletes

Study Design Retrospective cohort. Background Star Excursion Balance Test (SEBT) performance differs by sport in healthy collegiate athletes, and lower extremity injury rates also vary by sport, sex, and athletic exposure. The relationship between SEBT performance and injury risk has not been evaluated with consideration of these additional variables, which may be necessary to fully describe the relationship between SEBT performance and injury risk. Objectives To assess the association between preseason SEBT performance and noncontact injury occurrence to the knee or ankle in Division I collegiate athletes when controlling for sport, sex, and athletic exposure. Methods Star Excursion Balance Test performance, starting status, and injury status were reviewed retrospectively in National Collegiate Athletic Association Division I collegiate athletes from a single institution. A total of 147 athletes were healthy at the time of preseason SEBT testing and either remained healthy (n = 118) or sustained a noncontact injury to the knee or ankle (n = 29) during their sport's subsequent competitive season. Side-to-side asymmetries were calculated in each direction as the absolute difference in reach distance between limbs. Star Excursion Balance Test reach distances and asymmetries were compared between groups using multivariable regression, controlling for sport, sex, and athletic exposure (starter, nonstarter). Receiver operating characteristic curves were used to determine optimal sensitivity and specificity for significant models. Results When controlling for sport, sex, and athletic exposure, SEBT side-to-side asymmetry in the anterior direction, expressed as an absolute or normalized to limb length, discriminated between injured and noninjured athletes (area under the curve greater than 0.82). Conclusion Assessing side-to-side reach asymmetry in the anterior direction of the SEBT may assist in identifying collegiate athletes who are at risk for sustaining noncontact injuries to the knee or ankle. Level of Evidence Prognosis, level 2b. J Orthop Sports Phys Ther 2017;47(5):339-346. Epub 29 Mar 2017. doi:10.2519/jospt.2017.6974.

Volitional Spine Stabilization During a Drop Vertical Jump From Different Landing Heights: Implications for Anterior Cruciate Ligament Injury

CONTEXT

Volitional preemptive abdominal contraction (VPAC) during dynamic activities may alter trunk motion, but the role of the core musculature in positioning the trunk during landing tasks is unclear.

OBJECTIVE

To determine whether volitional core-muscle activation incorporated during a drop vertical jump alters lower extremity kinematics and kinetics, as well as trunk and lower extremity muscle activity at different landing heights.

DESIGN

Controlled laboratory study.

SETTING

Clinical biomechanics laboratory.

PATIENTS OR OTHER PARTICIPANTS

Thirty-two young healthy adults, consisting of 17 men (age = 25.24 ± 2.88 years, height = 1.85 ± 0.06 m, mass = 89.68 ± 16.80 kg) and 15 women (age = 23.93 ± 1.33 years, height = 1.67 ± 0.08 m, mass = 89.68 ± 5.28 kg).

INTERVENTION(S)

Core-muscle activation using VPAC.

MAIN OUTCOME MEASURE(S)

We collected 3-dimensional ankle, knee, and hip motions, moments, and powers; ground reaction forces; and trunk and lower extremity muscle activity during 0.30- and 0.50-m drop vertical-jump landings.

RESULTS

During landing from a 0.30-m height, VPAC performance increased external oblique and semitendinosis activity, knee flexion, and knee internal rotation and decreased knee-abduction moment and knee-energy absorption. During the 0.50-m landing, the VPAC increased external oblique and semitendinosis activity, knee flexion, and hip flexion and decreased ankle inversion and hip-energy absorption.

CONCLUSIONS

The VPAC performance during landing may protect the anterior cruciate ligament during different landing phases from different heights, creating a protective advantage just before ground contact and after the impact phase. Incorporating VPAC during high injury-risk activities may enhance pelvic stability, improve lower extremity positioning and sensorimotor control, and reduce anterior cruciate ligament injury risk while protecting the lumbar spine.

Predicting Injury: Challenges in Prospective Injury Risk Factor Identification

CONTEXT

Musculoskeletal injury-prediction methods vary and may have limitations that affect the accuracy of results and clinical meaningfulness.

BACKGROUND

Research examining injury risk factors is meaningful, but attempting to extrapolate injury risk from studies that do not prospectively assess injury occurrence may limit clinical applications. Injury incidence is a vital outcome measure, which allows for the appropriate interpretation of injury-prediction analyses; a lack of injury-incidence data may decrease the accuracy and increase the uncertainty of injury-risk estimates. Extrapolating results that predict an injury risk factor to predicting actual injuries may lead to inappropriate clinical decision-making models.

CONCLUSIONS

Improved understanding of the limitations of injury-prediction methods, specifically those that do not prospectively assess injuries, will allow clinicians to better assess the clinical meaningfulness of the results.

A Sport Fitness Index for Assessment of Sport-Related Injury Risk

OBJECTIVE

To develop and validate a concise survey that will identify athletes who possess elevated injury risk.

DESIGN

Cohort study.

SETTING

National Collegiate Athletic Association Division I athletic program.

PARTICIPANTS

Cohorts of 188 and 146 college athletes who participated during successive academic years.

ASSESSMENT OF RISK FACTORS

The first cohort provided responses to 4 joint-specific outcome surveys that were related to subsequent time-loss injury occurrence. Receiver operating characteristic analysis identified survey items that provided best discrimination, which were combined with a negative life event stress item to create a new 10-item survey. The second cohort provided responses to the new survey, which were converted to a 0 to 100 score.

MAIN OUTCOME MEASURES

Construct validity was assessed through documentation of time-loss injuries sustained during the preceding 12 months and predictive validity was assessed through prospective documentation of sport-related sprains and strains. Cronbach alpha was calculated to assess internal consistency.

RESULTS

Each of the outcome survey items used to develop the new survey demonstrated much greater specificity than sensitivity. Both the retrospective and prospective receiver operating characteristic (ROC) analyses identified scores of 96 and 88 as cut-points that provided good discrimination between injured and noninjured cases. The area under the curve was 0.69 (P < 0.001) for the retrospective analysis and 0.62 (P = 0.016) for the prospective analysis. Cronbach alpha was 0.89 (90% CI, 0.86-0.91).

CONCLUSIONS

Self-reported effects of previous injury may be one method to efficiently identify athletes who possess elevated injury risk, and subsequently deliver preventive interventions, thereby providing an alternative method to time-intensive functional testing.

Effects of body mass index on foot posture alignment and core stability in a healthy adult population

Foot biomechanics and core stability (CS) play significant roles in the quality of standing and walking. Minor alterations in body composition may influence base support or CS strategies. The aim of this study was to investigate the effect of the body mass index (BMI) on the foot posture index (FPI) and CS in a healthy adult population. A total of 39 healthy adult subjects with a mean age of 24.3±6.4 years and over-weight BMI values between 25 and 29.9 kg/m2 (27.43±6.1 kg/m2) participated in this study. Foot biomechanics were analyzed using the FPI. CS was assessed using a plank test with a time-to-failure trial. The Spearman correlation coefficient indicated a significant correlation between BMI and both the FPI (r=0.504, P=0.001) and CS (r= -0.34, P=0.036). Present study concluded that an overweight BMI influences foot posture alignment and body stability. Consequently, BMI should be considered during rehabilitation management for lower extremity injuries and body balance.