Predicting Subsequent Injury after Being Cleared to Return to Work from Initial Lumbar or Lower Extremity Injury.

PURPOSE: The purpose of this study is to develop a model to predict re-injury after being cleared to return to full duty from an initial injury. METHODS: This was a prediction model derivation cohort study. Military service members cleared for unrestricted full duty after sustaining a musculoskeletal injury were enrolled from three large military hospitals. Medical history, demographics, psychological profile, physical performance (Y-Balance Test™, Functional Movement Screen™, Selective Functional Movement Assessment, triple hop, closed chain ankle dorsiflexion, 2-mile run, 75% bodyweight carry time), and past injury history were assessed. Monthly text messages, medical records and limited duty databases were used to identify injuries resulting in time lost from work in the following year. RESULTS: Four hundred fifty participants (65 females), ages 18 to 45 yr were analyzed. Fifteen variables were included in the final model. The area under the curve was 0.74 (95% confidence interval, 0.69-0.80), indicating good performance. The calibration score of the model was 1.05 (95% confidence interval, 0.80-1.30) indicating very good performance. With an injury incidence in our cohort of 38.0%, the treat all net benefit was 0.000, and the net benefit of our predictive model was 0.251. This means 25 additional soldiers out of every 100 were correctly identified as high risk for injury compared with not using a prediction model at all. CONCLUSIONS: This multivariable model accurately predicted injury risk after returning for full duty and was better than not using a prediction model at all (an additional 25 of every 100 tactical athletes were correctly identified). This model provides guidance for proper decision making about when these individuals are not ready to return to full duty, with higher risk of a subsequent injury.

Restorative Neurostimulation: A Clinical Guide for Therapy Adoption.

In this review, we present a comprehensive clinical approach to restorative neurostimulation, a novel form of stimulation for refractory chronic mechanical low back pain, targeting impaired neuromuscular control and degeneration of the multifidus muscle. We focus on patient identification, technique guidance, and review of the scientific background and clinical evidence. As our understanding of back pain grows, there is clear evidence that impaired neuromuscular control and consequent degeneration of the multifidus muscle contribute to mechanical low back pain development and maintenance. We provide clinical guidance regarding an implantable restorative neurostimulation system that targets impaired neuromuscular control. Supported by results from a randomized, active-sham-controlled clinical trial with long-term follow-up, we provide clinicians with a comprehensive overview and practical clinical guidance for the adoption of this therapy modality.

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

PURPOSE: To 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. METHODS: SFMA 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. RESULTS: Only 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. CONCLUSIONS: One 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 EVIDENCE: Level III, retrospective comparative cohort study.

The Dorsiflexion Range of Motion Screen: A Validation Study.

BACKGROUND: Limited ankle dorsiflexion (DF) is associated with ankle sprains and other lower extremity injuries. Current ankle measurements can be laborious to perform in an athletic environment. PURPOSE: The purpose of this study was to determine the reliability and discriminant validity of a novel closed-chain ankle DF ROM test, the standing ankle dorsiflexion screen (SADS). STUDY DESIGN: Reliability and validity study. METHODS: Thirty-seven healthy subjects participated in the study. Two raters measured closed-chain ankle DF range of motion (ROM) using a modified lunge position with an electronic inclinometer. Four raters measured ankle DF using the SADS. Reliability was calculated using intraclass correlation coefficients (ICC) and kappa coefficients for the raters using an electronic inclinometer and the SADS scale, respectively. An independent t-test compared the SADS categories of "behind" and "beyond" to the modified lunge test ROM (p<0.05). RESULTS: Excellent ICC values (0.95 [95% CI (0.92,0.97)]) and high kappa values were observed (0.61-0.81), with high percent agreement (86-94%). There was a significant difference in ankle DF ROM between the nominally scored "behind" and "beyond" categories, regardless of rater or trial analyzed (behind: 41.3° ± 4.7°; beyond: 51.8°± SD 6.1°, p <0.001). CONCLUSIONS: The SADS was observed to have excellent interrater reliability and high discriminant validity. Furthermore, there was a distinct closed chain ankle DF ROM difference between the "behind" and "beyond" SADS nominal scores. CLINICAL RELEVANCE: The SADS can be used as a quick and efficient closed chain ankle DF ROM screen. LEVEL OF EVIDENCE: 2b.

Identification of Risk Factors Prospectively Associated With Musculoskeletal Injury in a Warrior Athlete Population.

BACKGROUND: Musculoskeletal injuries are a primary source of disability. Understanding how risk factors predict injury is necessary to individualize and enhance injury reduction programs. HYPOTHESIS: Because of the multifactorial nature of musculoskeletal injuries, multiple risk factors will provide a useful method of categorizing warrior athletes based on injury risk. STUDY DESIGN: Prospective observational cohort study. LEVEL OF EVIDENCE: Level 2. METHODS: Baseline data were collected on 922 US Army soldiers/warrior athletes (mean age, 24.7 ± 5.2 years; mean body mass index, 26.8 ± 3.4 kg/m2) using surveys and physical measures. Injury occurrence and health care utilization were collected for 1 year. Variables were compared in healthy versus injured participants using independent t tests or chi-square analysis. Significantly different factors between each group were entered into a logistic regression equation. Receiver operating characteristic curve and accuracy statistics were calculated for regression variables. RESULTS: Of the 922 warrior athletes, 38.8% suffered a time-loss injury (TLI). Overall, 35 variables had a significant relationship with TLIs. The logistic regression equation, consisting of 11 variables of interest, was significant (adjusted R2 = 0.21; odds ratio, 5.7 [95% CI, 4.1-7.9]; relative risk, 2.5 [95% CI, 2.1-2.9]; area under the curve, 0.73). Individuals with 2 variables had a sensitivity of 0.89, those with 7 or more variables had a specificity of 0.94. CONCLUSION: The sum of individual risk factors (prior injury, prior work restrictions, lower perceived recovery from injury, asymmetrical ankle dorsiflexion, decreased or asymmetrical performance on the Lower and Upper Quarter Y-Balance test, pain with movement, slower 2-mile run times, age, and sex) produced a highly sensitive and specific multivariate model for TLI in military servicemembers. CLINICAL RELEVANCE: A better understanding of characteristics associated with future injury risk can provide a foundation for prevention programs designed to reduce medical costs and time lost.

EXERCISE INTERVENTION FOR INDIVIDUALS WITH DYSFUNCTIONAL BREATHING: A MATCHED CONTROLLED TRIAL.

INTRODUCTION: Dysfunctional breathing (DB) is common (60-80%) in adults. Individuals with DB may have decreased pain thresholds, impaired motor control and balance, and movement dysfunction. These impairments likely adversely affect performance. Research has demonstrated that DB is multi-dimensional and includes biochemical, biomechanical, and psychophysiological categories. PURPOSE: The purpose of this study was to test the impact of breathing exercises in an otherwise healthy population of individuals diagnosed with at least one category of DB. It was hypothesized that the exercise program would normalize at least one category of DB. METHODS: An experimental group with DB was recruited, then the control group was matched for gender, age, BMI and activity. Baseline breathing metrics were obtained for each category of breathing dysfunction: capnography for biochemical (ETCO2 of < 35mmHg at rest = DB), HI-LO for biomechanical (upper chest or paradoxical patterns = DB), and Self-Evaluation of Breathing Questionnaire (SEBQ ≥ 25 = DB) and Nijmegen Questionnaire ( ≥ 22 = DB) for psychophysiological. The experimental group performed a four-week progression of home breathing exercises, once daily and the control group continued normal activities (no interventions). Re-testing of all outcome measures was performed after four weeks. RESULTS: Thirty-five individuals comprised the participant sample (16 experimental, 19 control, mean age 26.0 years, mean BMI of 24.3). There were no statistically significant differences between groups at baseline. Eighty-one percent of subjects in the experimental group improved in at least one category compared to 21% of subjects in the control group. Seventy-eight percent of subjects with biomechanical category of DB in the experimental group normalized this dysfunction, while none normalized in the control group, which was statistically significantly different. Twenty-seven percent of subjects with biochemical DB in the experimental group normalized, while only 25% in the control group which was not statistically different. There were only two subjects in each group with the psychophysiological category, therefore no analysis was performed. CONCLUSION: Home exercises were effective in reversing the biomechanical category of DB in 78% of young, otherwise healthy adults versus no exercise. However, the exercises did not affect the biochemical category of DB. Performing a set of home exercises may be an effective option for fitness and rehabilitation providers to suggest for clients to normalize biomechanical breathing dysfunction. LEVEL OF EVIDENCE: 2b.

THE EFFECT of ONE-ON-ONE INTERVENTION in ATHLETES with MULTIPLE RISK FACTORS for INJURY.

BACKGROUND: Lower extremity injuries in soccer players are extremely common. Implementation of group injury prevention programs has gained popularity due to time and cost-effectiveness. Unfortunately, players with greater number of risk factors are most likely to sustain an injury, yet less likely to benefit from a group injury prevention program. The purpose of this study was to determine if targeting these high risk players with one-on-one treatment would result in a reduction in the number of risk factors they possess. The authors hypothesized that fifty percent or more of subjects receiving one-on-one intervention would have a reduction of ≥1 risk factor(s). STUDY DESIGN: Quasi-experimental pretest-posttest design. METHODS: Division I men's and women's soccer players were screened for modifiable risk factors using a battery of tests which assessed mobility, fundamental movement pattern performance, motor control, and pain. Players with ≥ 3 risk factors ("high risk") received one-on-one treatment from a physical therapist via an algorithm twice per week for four weeks. Players with < 3 risk factors ("low risk") did not receive one-on-one intervention. RESULTS: The proportion of treatment successes in the intervention group was 0.923 (95% CI 0.640-0.998). A significant proportion of high risk subjects (0.846) became low risk at posttest (p = 0.003). A significant between group difference was noted in risk factor change from pretest to posttest (p = 0.002), with the median risk factor change in the intervention group being -3. CONCLUSION: Utilizing one-on-one interventions designed to target evidence-based risk factors is an effective strategy to eliminate LE musculoskeletal injury risk factors in high risk individuals. LEVELS OF EVIDENCE: 2b.

CAN INJURY RISK CATEGORY BE CHANGED IN ATHLETES? AN ANALYSIS OF AN INJURY PREVENTION SYSTEM.

BACKGROUND AND PURPOSE: Researchers have used an injury risk algorithm utilizing demographic data, injury history, the Functional Movement Screen™ (FMS™) and Lower Quarter Y Balance Test™ (YBT™) scores to categorize individual injury risk. The purpose of this study was to identify if a group-based hybrid injury prevention program utilizing key factors from previous research with the addition of an individualized approach can modify the injury risk category of athletes. STUDY DESIGN: Cohort Study. METHODS: Forty-four female subjects (ages 14-17) were recruited from a local high school soccer team. Pre-participation testing included demographic data, injury history, FMS™ and YBT™ to determine if each athletes' injury risk category using the Move2Perform algorithm. Post-testing took place after an eight-week exercise-based intervention program was completed. McNemar analysis was utilized to assess changes in the injury risk categories. RESULTS: A significant number of athletes (21 of 44) moved to lower risk categories at posttest (p=0.000; Z=-3.869). Of the 32 athletes in the High Risk category at pretest, 16 were Low Risk after the intervention (p=0.002). CONCLUSIONS: A preseason, group injury prevention training program with individually prescribed corrective exercises, resulted in a significant number of subjects decreasing their injury risk category. The primary statistically significant decrease of injury risk category was seen in the Moderate Risk individuals moving down to Slight. There were three athletes that moved from the Substantial Risk category to Slight, however, this change was not statistically significant. LEVEL OF EVIDENCE: 2.

Incidence of Musculoskeletal Injury in US Army Unit Types: A Prospective Cohort Study.

BACKGROUND: Musculoskeletal injuries during military service are a primary source of disability, resulting in 2.4 million annual health care visits and 25 million limited-duty days. While the injury incidence during basic training is well documented, there is little understanding of injury distribution by organization type in the US Army following initial training. OBJECTIVE: To compare injury incidence, distribution, and impact across various military units. METHODS: In this prospective observational cohort study, comprehensive injury data from subject questionnaires and medical chart reviews were collected over 12 months for 1430 initially healthy Army personnel, representing combat, combat support, combat service support, and ranger units. Health care utilization and time loss due to injury were also collected. RESULTS: Of 1430 soldiers, 481 (33.6%) had time-loss injury, 222 (15.5%) were injured without limited work, 60 (4.2%) reported an injury but did not seek medical care, and 667 (46.6%) were uninjured. Across the whole sample, injuries were responsible for 5.9 ±14.4 medical visits per soldier, 21 902 days of limited work, and $1 337 000 ($1901 ± $6535 per soldier) in medical costs. Considering only those reporting injury, each person averaged 36.3 ± 59.7 limited-work days. The injury incidence was highest in combat service support units (65.6%), with a risk ratio 1.60 times that of the reference group (combat, 41.1%). CONCLUSION: Combat support and combat service support personnel were more likely to have 1 or more injuries compared to rangers and combat personnel. The higher relative risk of injury in support units should be explored further. J Orthop Sports Phys Ther 2018;48(10):749-757. Epub 22 May 2018. doi:10.2519/jospt.2018.7979.

Developing predictive models for return to work using the Military Power, Performance and Prevention (MP3) musculoskeletal injury risk algorithm: a study protocol for an injury risk assessment programme.

BACKGROUND: Musculoskeletal injuries are a primary source of disability in the US Military, and low back pain and lower extremity injuries account for over 44% of limited work days annually. History of prior musculoskeletal injury increases the risk for future injury. This study aims to determine the risk of injury after returning to work from a previous injury. The objective is to identify criteria that can help predict likelihood for future injury or re-injury. METHODS: There will be 480 active duty soldiers recruited from across four medical centres. These will be patients who have sustained a musculoskeletal injury in the lower extremity or lumbar/thoracic spine, and have now been cleared to return back to work without any limitations. Subjects will undergo a battery of physical performance tests and fill out sociodemographic surveys. They will be followed for a year to identify any musculoskeletal injuries that occur. Prediction algorithms will be derived using regression analysis from performance and sociodemographic variables found to be significantly different between injured and non-injured subjects. DISCUSSION: Due to the high rates of injuries, injury prevention and prediction initiatives are growing. This is the first study looking at predicting re-injury rates after an initial musculoskeletal injury. In addition, multivariate prediction models appear to have move value than models based on only one variable. This approach aims to validate a multivariate model used in healthy non-injured individuals to help improve variables that best predict the ability to return to work with lower risk of injury, after a recent musculoskeletal injury. TRIAL REGISTRATION NUMBER: NCT02776930.

Muscle Control and Non-specific Chronic Low Back Pain.

OBJECTIVES: Chronic low back pain (CLBP) is the most prevalent of the painful musculoskeletal conditions. CLBP is a heterogeneous condition with many causes and diagnoses, but there are few established therapies with strong evidence of effectiveness (or cost effectiveness). CLBP for which it is not possible to identify any specific cause is often referred to as non-specific chronic LBP (NSCLBP). One type of NSCLBP is continuing and recurrent primarily nociceptive CLBP due to vertebral joint overload subsequent to functional instability of the lumbar spine. This condition may occur due to disruption of the motor control system to the key stabilizing muscles in the lumbar spine, particularly the lumbar multifidus muscle (MF). METHODS: This review presents the evidence for MF involvement in CLBP, mechanisms of action of disruption of control of the MF, and options for restoring control of the MF as a treatment for NSCLBP. RESULTS: Imaging assessment of motor control dysfunction of the MF in individual patients is fraught with difficulty. MRI or ultrasound imaging techniques, while reliable, have limited diagnostic or predictive utility. For some patients, restoration of motor control to the MF with specific exercises can be effective, but population results are not persuasive since most patients are unable to voluntarily contract the MF and may be inhibited from doing so due to arthrogenic muscle inhibition. CONCLUSIONS: Targeting MF control with restorative neurostimulation promises a new treatment option.

DEVELOPMENT OF A SCREENING PROTOCOL TO IDENTIFY INDIVIDUALS WITH DYSFUNCTIONAL BREATHING.

INTRODUCTION: Dysfunctional breathing (DB) has been linked to health conditions including low back pain and neck pain and adversely effects the musculoskeletal system. Individuals with DB often have decreased pain thresholds and impaired motor control, balance, and movement. No single test or screen identifies DB, which is multi-dimensional, and includes biochemical, biomechanical, and psychophysiological components. Several tools assess and test for DB, but no screen exists to determine whether additional testing and assessment are indicated. PURPOSE/BACKGROUND: The purpose of this study was to develop a breathing screening procedure that could be utilized by fitness and healthcare providers to screen for the presence of disordered breathing. A diagnostic test study approach was utilized to establish the diagnostic accuracy of the newly developed screen for DB. METHODS: A convenience sample of 51 subjects (27 females, 27.0 years, BMI 23.3) were included. To test for DB related to the biochemical dimension, end-tidal CO2 (ETCO2) was measured with a capnography unit. To test for DB related to biomechanical dimension, the Hi-Lo test was utilized. To test for DB related to the psychophysiological dimension, the Self Evaluation of Breathing Symptoms Questionnaire (SEBQ) and Nijmegen questionnaires were utilized. Potential screening items that have been shown to be related to DB in previous research and that could be performed by non-health care personnel were utilized to create the index test including activity level, breath hold time (BHT), respiration rate, and the Functional Movement Screen (FMS™). RESULTS: There were no strong correlations between the three measures of DB. Five subjects had normal breathing, 14 failed at least one measure, 20 failed at least two, and 12 failed all three. To develop screening items for each dimension, data were examined for association with failure. BHT and a four-item mini-questionnaire were identified as the most closely associated variables with failure of all three dimensions. A BHT of < 25 seconds and four questions were combined and yielded a sensitivity of 0.89 (0.85-0.93) and a specificity of 0.60 (0.18-0.92) for clinical identification of DB. CONCLUSION: Easily obtained clinical measures of BHT and four questions can be utilized to screen for the presence of DB. If the screen is passed, there is an 89% chance that DB is not present. If the screen is failed, further assessment is recommended. LEVEL OF EVIDENCE: 2b.

Association of Physical Inactivity, Weight, Smoking, and Prior Injury on Physical Performance in a Military Setting.

CONTEXT: Although inactivity, being overweight, smoking, and a history of injury are identified as risk factors for poor health and injury, few authors have examined their association on physical performance. Young adults may be more likely to adopt healthier lifestyles if they understand the effect of health behaviors on performance. OBJECTIVE: To determine the association of being overweight, smoking, inactivity, and a history of injury with physical performance. DESIGN: Cross-sectional study. SETTING: Military population. PATIENTS OR OTHER PARTICIPANTS: Active-duty service members (N = 1466; 1380 men, 86 women; age = 24.7 ± 5.0 years; body mass index = 26.7 ± 3.4 kg/m2). MAIN OUTCOME MEASURE(S): Participants performed 8 measures (the triple-crossover hop for distance, the 6-m timed-hop test, the Functional Movement Screen, the Lower Quarter Y-Balance Test, the Upper Quarter Y-Balance Test, and the 3-event Army Physical Fitness Test) for evaluation of endurance, strength, muscular endurance, power, agility, balance, and motor control. Participants were categorized based on the number of health risk factors present. Using an analysis of covariance, we assessed the relationship between risk factors and physical performance with age and sex as covariates. RESULTS: Compared with those who had no risk factors (27.9% of men, 34.9% of women), physical performance was worse in those who had 1, 2, or 3 to 4 risk factors present by 4.3%, 6.7%, and 10.3%, respectively. Decrements in performance for those with 3 to 4 risk factors ranged from 3.3% to 14.4%. CONCLUSIONS: An unhealthy lifestyle habit or a history of injury was negatively associated with physical performance. Physical performance decrements were associated with the number of risk factors present. Understanding how risk factors contribute to decreased physical performance may enable clinicians to improve compliance with injury-prevention programs in occupational settings in which a young and relatively healthy workforce may be more concerned about performance than health.

Application of Athletic Movement Tests that Predict Injury Risk in a Military Population: Development of Normative Data.

Performance on movement tests helps to predict injury risk in a variety of physically active populations. Understanding baseline measures for normal is an important first step. OBJECTIVES: Determine differences in physical performance assessments and describe normative values for these tests based on military unit type. METHODS: Assessment of power, balance, mobility, motor control, and performance on the Army Physical Fitness Test were assessed in a cohort of 1,466 soldiers. Analysis of variance was performed to compare the results based on military unit type (Rangers, Combat, Combat Service, and Combat Service Support) and analysis of covariance was performed to determine the influence of age and gender. RESULTS: Rangers performed the best on all performance and fitness measures (p < 0.05). Combat soldiers performed better than Combat Service and Service Support soldiers on several physical performance tests and the Army Physical Fitness Test (p < 0.05). Performance in Combat Service and Service Support soldiers was equivalent on most measures (p < 0.05). CONCLUSIONS: Functional performance and level of fitness varied significantly by military unit type. Understanding these differences will provide a foundation for future injury prediction and prevention strategies.

What Risk Factors Are Associated With Musculoskeletal Injury in US Army Rangers? A Prospective Prognostic Study.

BACKGROUND: Musculoskeletal injury is the most common reason that soldiers are medically not ready to deploy. Understanding intrinsic risk factors that may place an elite soldier at risk of musculoskeletal injury may be beneficial in preventing musculoskeletal injury and maintaining operational military readiness. Findings from this population may also be useful as hypothesis-generating work for particular civilian settings such as law enforcement officers (SWAT teams), firefighters (smoke jumpers), or others in physically demanding professions. QUESTIONS/PURPOSES: The purposes of this study were (1) to examine whether using baseline measures of self-report and physical performance can identify musculoskeletal injury risk; and (2) to determine whether a combination of predictors would enhance the accuracy for determining future musculoskeletal injury risk in US Army Rangers. METHODS: Our study was a planned secondary analysis from a prospective cohort examining how baseline factors predict musculoskeletal injury. Baseline predictors associated with musculoskeletal injury were collected using surveys and physical performance measures. Survey data included demographic variables, injury history, and biopsychosocial questions. Physical performance measures included ankle dorsiflexion, Functional Movement Screen, lower and upper quarter Y-balance test, hop testing, pain provocation, and the Army Physical Fitness Test (consisting of a 2-mile run and 2 minutes of sit-ups and push-ups). A total of 320 Rangers were invited to enroll and 211 participated (66%). Occurrence of musculoskeletal injury was tracked for 1 year using monthly injury surveillance surveys, medical record reviews, and a query of the Department of Defense healthcare utilization database. Injury surveillance data were available on 100% of the subjects. Receiver operator characteristic curves and accuracy statistics were calculated to identify predictors of interest. A logistic regression equation was then calculated to find the most pertinent set of predictors. Of the 188 Rangers (age, 23.3 ± 3.7 years; body mass index, 26.0 ± 2.4 kg/m(2)) remaining in the cohort, 85 (45.2%) sustained a musculoskeletal injury of interest. RESULTS: Smoking, prior surgery, recurrent prior musculoskeletal injury, limited-duty days in the prior year for musculoskeletal injury, asymmetrical ankle dorsiflexion, pain with Functional Movement Screen clearing tests, and decreased performance on the 2-mile run and 2-minute sit-up test were associated with increased injury risk. Presenting with one or fewer predictors resulted in a sensitivity of 0.90 (95% confidence interval [CI], 0.83-0.95), and having three or more predictors resulted in a specificity of 0.98 (95% CI, 0.93-0.99). The combined factors that contribute to the final multivariable logistic regression equation yielded an odds ratio of 4.3 (95% CI, 2.0-9.2), relative risk of 1.9 (95% CI, 1.4-2.6), and an area under the curve of 0.64. CONCLUSIONS: Multiple factors (musculoskeletal injury history, smoking, pain provocation, movement tests, and lower scores on physical performance measures) were associated with individuals at risk for musculoskeletal injury. The summation of the number of risk factors produced a highly sensitive (one or less factor) and specific (three or more factors) model that could potentially be used to effectively identify and intervene in those persons with elevated risk for musculoskeletal injury. Future research should establish if screening and intervening can improve musculoskeletal health and if our findings among US Army Rangers translate to other occupations or athletes. LEVEL OF EVIDENCE: Level II, prognostic study.

Bilateral differences in the upper quarter function of high school aged baseball and softball players.

PURPOSE/BACKGROUND: The Upper Quarter Y Balance Test (YBT-UQ) was developed as a way to identify upper extremity and trunk mobility in the open kinetic chain in the reaching limb as well as midrange limitations and asymmetries of upper extremity and core stability in the closed kinetic chain on the stabilizing limb. Performance on the YBT-UQ is similar between genders and between limbs; however, this has not been examined in athletes who participate in sports that result in upper extremity asymmetries. The primary purpose of this study is to determine if differences exist between the throwing vs. non-throwing sides in high-school baseball and softball athletes on the YBT-UQ. METHODS: In order to complete this forty-eight male high school baseball players and seventeen female high school softball players were tested on the YBT-UQ. Reach distances were normalized to arm length (% AL). Comparisons were made between the throwing (T) and non-throwing (NT) arm for each direction as well as the composite score. RESULTS: No significant differences were observed between the T and NT arm for the medial (NT: 98.4 ± 8.6 %AL, T: 99.1 ± 8.6 %AL, p=0.42), inferolateral (NT: 90.8 ± 11.8 %AL, T: 90.3 ± 11.5 %AL, p =0.61), superolateral (NT: 70.6 ± 10.9 %AL, T: 70.4 ± 11.1 % AL, p=0.91) reaches, or the composite score (NT: 87.2 ± 8.9 % AL, T: 86.6 ± 8.1 %AL, p=0.72). Similarly, no differences were observed between the male baseball and female softball players (p=0.30-0.90). CONCLUSIONS: Based on these findings, it was concluded that there was no difference in performance on the YBT-UQ between throwing and non-throwing limbs in high school baseball and softball players. LEVEL OF EVIDENCE: 3.

Sex differences in dynamic closed kinetic chain upper quarter function in collegiate swimmers.

CONTEXT: Upper quarter injuries have a higher incidence in female swimmers; however, to date, there are few ways to assess the basic functional ability of this region. The upper quarter Y balance test (YBT-UQ) may assist in this process because it was developed to provide a fundamental assessment of dynamic upper quarter ability at the limit of stability. OBJECTIVE: To examine how sex affects performance on the YBT-UQ in swimmers. DESIGN: Cohort study. PATIENTS OR OTHER PARTICIPANTS: Forty-three male and 54 female National Collegiate Athletic Association Division I college swimmers were recruited preseason. MAIN OUTCOME MEASURE(S): We measured YBT-UQ performance for the left and right limbs in the medial, inferolateral, and superolateral directions. The maximum score for each direction was normalized to upper extremity length. The average of the greatest normalized reach scores in each reach direction was used to develop a composite score (average distance in 3 directions/limb length [LL] × 100). To examine reach symmetry between sexes, the difference in centimeters between the left and right sides was calculated for each reach direction prior to normalization. Statistical analysis was conducted using an independent-samples t test (P < .05). RESULTS: Average scores in the medial (women: 92.5 ± 7.4%LL, men: 100.0 ± 8.7%LL; P < .01) and inferolateral (women: 85.6 ± 10.3%LL, men: 89.8 ± 10.8%LL; P = .05) directions and composite score (women: 83.4 ± 8.3%LL, men: 88.3 ± 8.9%LL; P < .01) were higher in men than in women. No differences were observed for reach symmetry in any direction. CONCLUSIONS: Performance on several YBT-UQ indices was worse for female than male collegiate swimmers. These results may have implications for the use of preseason and return-to-sport testing in swimmers as a measurement of upper quarter function and symmetry.

Normative data and the influence of age and gender on power, balance, flexibility, and functional movement in healthy service members.

OBJECTIVES: Determine the influence of age and sex and describe normative data on field expedient tests associated with power, balance, trunk stability, mobility, and functional movement in a military population. METHODS: Participants (n = 247) completed a series of clinical and functional tests, including closed-chain ankle dorsiflexion (DF), Functional Movement Screen (FMS), Y-Balance Test Lower Quarter (YBT-LQ), Y-Balance Test Upper Quarter (YBT-UQ), single leg vertical jump (SLVJ), 6-m timed hop (6-m timed), and triple hop. Descriptive statistics were calculated. Analysis of variance tests were performed to compare the results based on sex and age (<30 years, >30 years). RESULTS: Service members demonstrated DF of 34.2 ± 6.1°, FMS composite score of 16.2 ± 2.2, YBT-LQ normalized composite score of 96.9 ± 8.6%, YBT-UQ normalized composite score of 87.6 ± 9.6%, SLVJ of 26.9 ± 8.6 cm, 6-m hop of 2.4 ± 0.5 seconds, and a triple hop of 390.9 ± 110.8 cm. Men performed greater than women (p < 0.05) on the YBT-LQ, YBT-UQ, SLVJ, 6-m timed, and triple hop. Those <30 years of age performed better than older participants (p < 0.05) on the DF, FMS, YBT-LQ, SLVJ, 6-m hop, and triple hop. CONCLUSIONS: Findings provide normative data on military members. Men performed better on power, balance, and trunk stability tests, whereas younger individuals performed better on power, balance, mobility, and functional movement.

Prediction of injury by limited and asymmetrical fundamental movement patterns in american football players.

CONTEXT: Previous injury is the strongest risk factor for future injury in sports. It has been proposed that motor-control changes such as movement limitation and asymmetry associated with injury and pain may be perpetuated as part of an individual's movement strategy. Motor control of fundamental 1-×-body-weight tasks can reliably and efficiently be measured in the field. OBJECTIVE: To determine whether the motor control of fundamental movement patterns and pattern asymmetry have a relationship with time-loss injury over the course of the preseason in professional football. DESIGN: Injury-risk study. SETTING: American professional football facilities. PARTICIPANTS: 238 American professional football players. INTERVENTION: To measure the motor control of 1-×-body-weight fundamental movement patterns, Functional Movement Screen scores were obtained before the start of training camp. The previously established cutoff score of ≤14 and the presence of any asymmetries on the FMS were examined using relative risk to determine if a relationship exists with time-loss injury. MAIN OUTCOME MEASURE: Time-loss musculoskeletal injury defined as any time loss from practice or competition due to musculoskeletal injury. RESULTS: Players who scored ≤14 exhibited a relative risk of 1.87 (CI95 1.202.96). Similarly, players with at least 1 asymmetry displayed a relative risk of 1.80 (CI95 1.112.74). The combination of scoring below the threshold and exhibiting a movement asymmetry was highly specific for injury, with a specificity of .87 (CI95 .84.90). CONCLUSION: The results of this study suggest that fundamental movement patterns and pattern asymmetry are identifiable risk factors for time-loss injury during the preseason in professional football players.

Comparison of dynamic balance in adolescent male soccer players from rwanda and the United States.

PURPOSE/BACKGROUND: Dynamic balance is an important component of motor skill development. Poor dynamic balance has previously been associated with sport related injury. However, the vast majority of dynamic balance studies as they relate to sport injury have occurred in developed North American or European countries. Thus, the purpose of this study was to compare dynamic balance in adolescent male soccer players from Rwanda to a matched group from the United States. METHODS: Twenty-six adolescent male soccer players from Rwanda and 26 age- and gender-matched control subjects from the United States were screened using the Lower Quarter Y Balance Test during their pre-participation physical. Reach asymmetry (cm) between limbs was examined for all reach directions. In addition, reach distance in each direction (normalized to limb length, %LL) and the composite reach score (also normalized to %LL) were examined. Dependent samples t-tests were performed with significant differences identified at p<0.05. RESULTS: Twenty-six male soccer players from Rwanda (R) were matched to twenty-six male soccer players from the United States (US). The Rwandan soccer players performed better in the anterior (R: 83.9 ± 3.2 %LL; US: 76.5 ± 6.6 %LL, p<0.01), posterolateral (R: 114.4 ± 8.3 %LL ; US: 106.5 ± 8.2 %LL, p<0.01) and composite (R: 105.6 ± 1.3 %LL; US: 97.8 ± 6.2 %LL, p<0.01) reach scores. No significant differences between groups were observed for reach asymmetry. CONCLUSIONS: Adolescent soccer players from Rwanda exhibit superior performance on a standardized dynamic balance test as comparison to similar athletes from the United States. The examination of movement abilities of athletes from countries of various origins may allow for a greater understanding of the range of true normative values for dynamic balance. LEVELS OF EVIDENCE: 3b.