Barriers and facilitators to implementation of musculoskeletal injury mitigation programmes for military service members around the world: a scoping review.

INTRODUCTION: Musculoskeletal injury (MSK-I) mitigation and prevention programmes (MSK-IMPPs) have been developed and implemented across militaries worldwide. Although programme efficacy is often reported, development and implementation details are often overlooked, limiting their scalability, sustainability and effectiveness. This scoping review aimed to identify the following in military populations: (1) barriers and facilitators to implementing and scaling MSK-IMPPs; (2) gaps in MSK-IMPP research and (3) future research priorities. METHODS: A scoping review assessed literature from inception to April 2022 that included studies on MSK-IMPP implementation and/or effectiveness in military populations. Barriers and facilitators to implementing these programmes were identified. RESULTS: From 132 articles, most were primary research studies (90; 68.2%); the remainder were review papers (42; 31.8%). Among primary studies, 3 (3.3%) investigated only women, 62 (69%) only men and 25 (27.8%) both. Barriers included limited resources, lack of stakeholder engagement, competing military priorities and equipment-related factors. Facilitators included strong stakeholder engagement, targeted programme design, involvement/proximity of MSK-I experts, providing MSK-I mitigation education, low burden on resources and emphasising end-user acceptability. Research gaps included variability in reported MSK-I outcomes and no consensus on relevant surveillance metrics and definitions. CONCLUSION: Despite a robust body of literature, there is a dearth of information about programme implementation; specifically, barriers or facilitators to success. Additionally, variability in outcomes and lack of consensus on MSK-I definitions may affect the development, implementation evaluation and comparison of MSK-IMPPs. There is a need for international consensus on definitions and optimal data reporting elements when conducting injury risk mitigation research in the military.

Much work remains to reach consensus on musculoskeletal injury risk in military service members: A systematic review with meta-analysis.

Musculoskeletal injuries are the most common reason military service members cannot perform their military duties. Not only are they costly and associated with long-term disability, often long after completion of military service, but injuries also adversely affect the military readiness of a nation. This can be seen as a threat to national security and part of the impetus behind many efforts to better understand, predict, and mitigate injury risk in the military. A systematic review of the literature published between 1995 and October 31, 2020 was conducted to identify significant risk factors of musculoskeletal injury in military populations across the world. 74 out of 170 eligible studies addressed comprehensive injuries, providing 994 unique risk factors. 46 of these studies provided data that could be included in a meta-analysis, which was possible for 15 predictor variables. Seven predictors were significant in meta-analysis: female sex(RR=1.46;95CI 1.30,1.64), high body mass index(RR=1.36;95CI 1.21,1.53), functional movement screen pain (RR=1.70;95CI 1.55,1.87) or scores ≤ 14(RR=1.42 95CI 1.29,1.56), prior injury(RR=1.54;95CI 1.32,1.80), slower running performance(RR=1.33;95CI 1.18,1.51), and poorer push-up performance(RR=1.15;95CI 1.04,1.27). Low BMI, height, weight, smoking, physical activity scores, and sit-up and jump performance were not significant risk factors in the meta-analysis. Most studies had a high risk of bias. Lack of raw data and large heterogeneity in definitions of predictors and injury outcomes limited comparison across many studies.Highlights Female sex, high body mass index, pain with functional movement screen or a score of ≤ 14, prior injury, slower running performance and poorer push-up performance were all significant predictors of musculoskeletal injury.Low body mass index, height, weight, smoking, physical activity scores, and sit-up and jump performance were not significant predictors of musculoskeletal injury.Many other predictors were present only in single studies, but large heterogeneity in definitions of both outcomes and predictors limited comparison across studies.Overall, studies assessing risk factors to predict musculoskeletal injuries in the military were at high risk for bias, especially in regards to statistical approaches.

Musculoskeletal Injuries and United States Army Readiness Part I: Overview of Injuries and their Strategic Impact.

INTRODUCTION: Noncombat injuries ("injuries") greatly impact soldier health and United States (U.S.) Army readiness; they are the leading cause of outpatient medical encounters (more than two million annually) among active component (AC) soldiers. Noncombat musculoskeletal injuries ("MSKIs") may account for nearly 60% of soldiers' limited duty days and 65% of soldiers who cannot deploy for medical reasons. Injuries primarily affect readiness through increased limited duty days, decreased deployability rates, and increased medical separation rates. MSKIs are also responsible for exorbitant medical costs to the U.S. government, including service-connected disability compensation. A significant subset of soldiers develops chronic pain or long-term disability after injury; this may increase their risk for chronic disease or secondary health deficits potentially associated with MSKIs. The authors will review trends in U.S. Army MSKI rates, summarize MSKI readiness-related impacts, and highlight the importance of standardizing surveillance approaches, including injury definitions used in injury surveillance. MATERIALS/METHODS: This review summarizes current reports and U.S. Department of Defense internal policy documents. MSKIs are defined as musculoskeletal disorders resulting from mechanical energy transfer, including traumatic and overuse injuries, which may cause pain and/or limit function. This review focuses on various U.S. Army populations, based on setting, sex, and age; the review excludes combat or battle injuries. RESULTS: More than half of all AC soldiers sustained at least one injury (MSKI or non-MSKI) in 2017. Overuse injuries comprise at least 70% of all injuries among AC soldiers. Female soldiers are at greater risk for MSKI than men. Female soldiers' aerobic and muscular fitness performances are typically lower than men's performances, which could account for their higher injury rates. Older soldiers are at greater injury risk than younger soldiers. Soldiers in noncombat arms units tend to have higher incidences of reported MSKIs, more limited duty days, and higher rates of limited duty days for chronic MSKIs than soldiers in combat arms units. MSKIs account for 65% of medically nondeployable AC soldiers. At any time, 4% of AC soldiers cannot deploy because of MSKIs. Once deployed, nonbattle injuries accounted for approximately 30% of all medical evacuations, and were the largest category of soldier evacuations from both recent major combat theaters (Iraq and Afghanistan). More than 85% of service members medically evacuated for MSKIs failed to return to the theater. MSKIs factored into (1) nearly 70% of medical disability discharges across the Army from 2011 through 2016 and (2) more than 90% of disability discharges within enlisted soldiers' first year of service from 2010 to 2015. MSKI-related, service-connected (SC) disabilities account for 44% of all SC disabilities (more than any other body system) among compensated U.S. Global War on Terrorism veterans. CONCLUSIONS: MSKIs significantly impact soldier health and U.S. Army readiness. MSKIs also figure prominently in medical disability discharges and long-term, service-connected disability costs. MSKI patterns and trends vary between trainees and soldiers in operational units and among military occupations and types of operational units. Coordinated injury surveillance efforts are needed to provide standardized metrics and accurately measure temporal changes in injury rates.

Musculoskeletal Injuries and United States Army Readiness. Part II: Management Challenges and Risk Mitigation Initiatives.

INTRODUCTION: Noncombat injuries ("injuries") threaten soldier health and United States (U.S.) Army medical readiness, accounting for more than twice as many outpatient medical encounters among active component (AC) soldiers as behavioral health conditions (the second leading cause of outpatient visits). Noncombat musculoskeletal injuries (MSKIs) account for more than 80% of soldiers' injuries and 65% of medically nondeployable AC soldiers. This review focuses on MSKI risk reduction initiatives, management, and reporting challenges within the Army. The authors will summarize MSKI risk reduction efforts and challenges affecting MSKI management and reporting within the U.S. Army. MATERIALS/METHODS: This review focuses on (1) initiatives to reduce the impact of MSKIs and risk for chronic injury/pain or long-term disability and (2) MSKI reporting challenges. This review excludes combat or battle injuries. RESULTS: Primary risk reduction Adherence to standardized exercise programming has reduced injury risk among trainees. Preaccession physical fitness screening may identify individuals at risk for injury or attrition during initial entry training. Forward-based strength and conditioning coaching (provided in the unit footprint) and nutritional supplementation initiatives are promising, but results are currently inconclusive concerning injury risk reduction. SECONDARY RISK REDUCTION: Forward-based access to MSKI care provided by embedded athletic trainers and physical therapists within military units or primary care clinics holds promise for reducing MSKI-related limited duty days and nondeployability among AC soldiers. Early point-of-care screening for psychosocial risk factors affecting responsiveness to MSKI intervention may reduce risk for progression to chronic pain or long-term disability. TERTIARY RISK REDUCTION: Operational MSKI metrics enable commanders and clinicians to readily identify soldiers with nonresolving MSKIs. Monthly injury reports to Army leadership increase command focus on soldiers with nonresolving MSKIs. CONCLUSIONS: Standardized exercise programming has reduced trainee MSKI rates. Secondary risk reduction initiatives show promise for reducing MSKI-related duty limitations and nondeployability among AC soldiers; timely identification/evaluation and appropriate, early management of MSKIs are essential. Tertiary risk reduction initiatives show promise for identifying soldiers whose chronic musculoskeletal conditions may render them unfit for continued military service.Clinicians must document MSKI care with sufficient specificity (including diagnosis and external cause coding) to enable large-scale systematic MSKI surveillance and analysis informing focused MSKI risk reduction efforts. Historical changes in surveillance methods and injury definitions make it difficult to compare injury rates and trends over time. However, the U.S. Army's standardized injury taxonomy will enable consistent classification of current and future injuries by mechanism of energy transfer and diagnosis. The Army's electronic physical profiling system further enablesstandardized documentation of MSKI-related duty/work restrictions and mechanisms of injury. These evolving surveillance tools ideally ensure continual advancement of military injury surveillance and serve as models for other military and civilian health care organizations.

Injury Surveillance and Reporting for Trainees with Bone Stress Injury: Current Practices and Recommendations.

Background: Musculoskeletal injuries, including lower extremity bone stress injuries (BSI) significantly impact initial entry training (IET) in the U.S. Army due to limited duty days, trainee attrition, early medical discharge, and related financial costs. Factors complicating trainee BSI surveillance include inconsistent BSI coding practices, attrition documentation as both administrative separations and medical discharges and the inability to code for BSI grade or severity when using International Statistical Classification of Diseases and Related Health Problems 10th revision (ICD-10) codes. Methods: A multidisciplinary expert panel developed policy guidance to enhance clinical and administrative management of BSI, following extensive analysis of current, peer-reviewed literature. Policy guidance incorporates leading practices concerning clinical BSI management, including imaging procedures, recommended notifications, early intervention, and ICD-10 diagnostic coding procedures. Policy guidance also standardizes BSI grading criteria for magnetic resonance imaging and skeletal scintigraphy (bone scan). Findings: Multidisciplinary expert opinion indicates inconsistent BSI diagnosis and management across IET due to variability in trainee BSI grading, documentation, and coding practices. Injury surveillance conducted by the United States Army Medical Command (USAMEDCOM) will benefit from routine, standardized musculoskeletal injury data base searches by BSI severity/grade and anatomical location upon implementation of BSI policy guidance. Discussion: Effective injury surveillance is critical for determining trainee BSI incidence and attrition, developing anticipated return to duty (RTD) timelines, and assessing long-term outcomes. BSI RTD timelines should account for gender, BSI grade/severity, anatomical location, and type of intervention. Well-defined RTD timelines would benefit administrative decision-making purposes, including whether to grant convalescent leave or enroll in the Warrior Training and Rehabilitation Program during BSI recovery. Enhanced management procedures may improve initial enlistment completion rates for trainees sustaining at least one BSI who eventually complete IET.

Factors Influencing Running-Related Musculoskeletal Injury Risk Among U.S. Military Recruits.

Running-related musculoskeletal injuries among U.S. military recruits negatively impact military readiness. Low aerobic fitness, prior injury, and weekly running distance are known risk factors. Physical fitness screening and remedial physical training (or discharging the most poorly fit recruits) before entry-level military training have tended to reduce injury rates while decreasing attrition, training, and medical costs. Incorporating anaerobic running sessions into training programs can offset decreased weekly running distance and decrease injury risk. Varying lower extremity loading patterns, stride length or cadence manipulation, and hip stability/strengthening programming may further decrease injury risk. No footstrike pattern is ideal for all runners; transitioning to forefoot striking may reduce risk for hip, knee, or tibial injuries, but increase risk for calf, Achilles, foot or ankle injuries. Minimal evidence associates running surfaces with injury risk. Footwear interventions should focus on proper fit and comfort; the evidence does not support running shoe prescription per foot type to reduce injury risk among recruits. Primary injury mitigation efforts should focus on physical fitness screening, remedial physical training (or discharge for unfit recruits), and continued inclusion of anaerobic running sessions to offset decreased weekly running distance.

Triceps tendon tear in a middle-aged weightlifter.

The patient was a 47-year-old man who was evaluated by a physical therapist for a chief complaint of posterior right elbow pain. The patient routinely participated in weightlifting activities and reported a sudden onset of triceps weakness and posterior elbow pain while performing clap push-ups 3 days prior. A physician assistant ordered radiographs, which were initially interpreted as normal, and routine magnetic resonance imaging for the right elbow. Following examination by a physical therapist, due to concern for a triceps tendon tear, the previously ordered magnetic resonance imaging was expedited, which revealed a partial triceps tendon tear with partial tendon retraction medially.

Physical training injuries and interventions for military recruits.

Low physical fitness levels are associated with increased musculoskeletal injury risk and attrition among military recruits. The authors review physical fitness trends, injury risk factors, and Department of the Army initiatives to address recruit fitness, injuries, and attrition. Initiatives include the Fitness Assessment Program, which reduced injury risk and attrition among low-fit trainees, and the Assessment of Recruit Motivation and Strength, which enabled the Army to enlist individuals exceeding body composition accession standards without increasing attrition. Physical Readiness Training (PRT) is the Army's primary initiative to address training-related injuries and attrition. PRT's inherent injury control and exercise progression components are designed to address low fitness levels across entry-level training. PRT has been shown to decrease injury rates, but low-fit recruits remain at increased risk regardless of program design. The authors recommend resuming pre-enlistment fitness screening and fitness programming before low-fit recruits begin entry-level training. The decision whether to screen for fitness before beginning entry-level training could be based upon the existing recruiting environment in terms of applicant supply and the demand for recruits. However, the Army should anticipate increased injury and attrition rates when discontinuing screening and/or fitness programming for low-fit recruits.

Static foot posture associated with dynamic plantar pressure parameters.

STUDY DESIGN: Controlled laboratory study. OBJECTIVE: To explore potential associations between foot posture index (FPI-6) composite scores and dynamic plantar pressure measurements, and to describe each of the 6 subscales and the FPI-6 composite scores across our sample. BACKGROUND: The FPI-6 is a static foot posture assessment comprised of 6 observations. Extreme scores have been associated with increased injury risk. However, knowledge describing the relationship between FPI-6 scores and plantar pressure distributions during gait is limited. METHODS: Participants (n = 1000; 566 males, 434 females) were predominantly active adults (mean ± SD age, 30.6 ± 8.0 years; body mass index, 26.2 ± 3.7 kg/m²), who ran 3.1 ± 1.4 d/wk. Static and dynamic foot characteristics were compared using the FPI-6 and a capacitance-based pressure platform. Correlation and hierarchical stepwise regression analyses were performed to determine the most parsimonious set of dynamic pressure data associated with FPI-6 scores. RESULTS: The mean ± SD FPI-6 score was 3.4 ± 2.9 (range, -6.0 to 11.0). Only 31 participants received a score of -2 (supinated foot) on any FPI-6 subscale. Classification of a pronated foot was 2.4 times more likely than a supinated foot. A 5-variable model (R = 0.57, R2 = 0.32) was developed to describe the association between dynamic plantar pressures and FPI-6 scores. CONCLUSION: The multivariate model associated with FPI-6 scores comprised clinically plausible variables which inform the association between static and dynamic foot postures. Different cutoff values may be required when using the FPI-6 to screen for individuals with supinated feet, given the limited number of high-arched participants identified by FPI-6 classifications.

Awareness and compliance with recommended running shoe guidelines among U.S. Army soldiers.

The purpose of this study was to determine awareness and compliance with recommended running shoe selection, sizing, and replacement guidelines among U.S. Army soldiers. Soldiers (n = 524) attending training at Fort Sam Houston, Texas completed self-report questionnaires and a foot assessment, which included measurement of foot size and arch height index. Researchers examined each soldier's running shoes for type, wear pattern, and general condition. Thirty-five percent of the soldiers wore shoes that were inappropriately sized; 56.5% wore shoes that were inappropriate for their foot type. Thirty-five percent of the soldiers had excessively worn shoes and 63% did not know recommended shoe replacement guidelines. Further efforts may be necessary to ensure that soldiers are aware of and compliant with recommended running shoe selection, sizing, and replacement guidelines. Future research is needed to determine whether adherence to these guidelines has a favorable effect on reducing risk of overuse injury.

Changes in lateral abdominal muscle thickness during the abdominal drawing-in maneuver in those with lumbopelvic pain.

STUDY DESIGN: Controlled laboratory study. OBJECTIVES: To determine if changes in transversus abdominis (TrA) and internal oblique (IO) muscle thickness and side-to-side symmetry differ in individuals with and without unilateral lumbopelvic pain while at rest and during the abdominal drawing-in maneuver (ADIM). BACKGROUND: Although the ADIM has been found to produce a symmetrical change in TrA and IO muscle thickness in healthy subjects, how these muscles are activated in those with unilateral lumbopelvic pain during the ADIM remains unknown. METHODS: Fifteen subjects with lumbopelvic pain and 15 age- and gender-matched control subjects were recruited. To investigate a similar subgroup of patients with lumbopelvic pain that has been used in previous research, subjects were required to have unilateral symptoms, a positive sacroiliac provocation test, and a positive active straight-leg raise test. Ultrasound images were obtained bilaterally at 2 different points during each trial of the ADIM: (1) at rest and (2) while maintaining the ADIM. Average percent change in thickness of the TrA and IO muscles was obtained over 3 trials. RESULTS: The percent change in thickness of the TrA was 20.9% less in those with lumbopelvic pain compared to the control group (P = .035), while the percent change in IO thickness was equivalent between groups (P = .522). No differences were observed for the TrA or IO muscles between the symptomatic and asymptomatic sides in those with (TrA, P = .263; IO, P = .172) or without (TrA, P = .780; IO, P = .635) lumbopelvic pain during the ADIM. Changes in TrA muscle thickness were greater than the IO muscle during the ADIM for both groups (P<.001). Specifically, the increases in TrA muscle thickness in those with and without lumbopelvic dysfunction were 32.7% and 47.3% greater, respectively, compared to changes in the IO muscle. CONCLUSIONS: Individuals with unilateral lumbopelvic pain demonstrated a smaller increase in thickness of the TrA muscle during the ADIM. This finding provides an element of construct validity for the use of the ADIM for assessing TrA muscle thickness in those with unilateral lumbopelvic pain. However, both groups demonstrated a symmetrical side-to-side change in TrA and IO muscle thickness despite the symptomatic group having unilateral symptoms. Further, we detected a preferential change in TrA muscle thickness during the ADIM in both groups.

Effect of running shoe type on the distribution and magnitude of plantar pressures in individuals with low- or high-arched feet.

BACKGROUND: Research addressing the effect of running shoe type on the low- or high-arched foot during gait is limited. We sought 1) to analyze mean plantar pressure and mean contact area differences between low- and high-arched feet across three test conditions, 2) to determine which regions of the foot (rearfoot, midfoot, and forefoot) contributed to potential differences in mean plantar pressure and mean contact area, and 3) to determine the association between the static arch height index and the dynamic modified arch index. METHODS: Plantar pressure distributions for 75 participants (40 low arched and 35 high arched) were analyzed across three conditions (nonshod, motion control running shoes, and cushioning running shoes) during treadmill walking. RESULTS: In the motion control and cushioning shoe conditions, mean plantar contact area increased in the midfoot (28% for low arched and 68% for high arched), whereas mean plantar pressure decreased by approximately 30% relative to the nonshod condition. There was moderate to good negative correlation between the arch height index and the modified arch index. CONCLUSIONS: Cushioning and motion control running shoes tend to increase midfoot mean plantar contact area while decreasing mean plantar pressure across the low- or high-arched foot.

Dynamic plantar pressure parameters associated with static arch height index during gait.

BACKGROUND: Although extreme values of arch height have been associated with increased risk for overuse injury, knowledge is limited regarding the association between arch height and plantar pressure distributions during gait. The primary purpose of this study was to explore which plantar pressure measurements during gait were associated with static arch height and arch height index. METHODS: Static arch height, arch height index, and dynamic plantar pressure distributions were collected for 1000 subjects (566 males, 434 females, 30.6 [SD 8.0] years, 171.1 [SD 9.3]cm, 76.9 [SD 14.7]kg). A hierarchical regression analysis was performed to determine the most parsimonious set of plantar pressure parameters associated with arch height. The predicted values were used to calculate dynamic arch height index. Correlation and residual analysis were performed to assess the association between statically and dynamically determined arch height indices. FINDINGS: A 5-variable model (F = 296.6; P < 0.001) was able to describe the relationship between static arch height and the dynamic foot during gait (R =0 .77 [95% CI = 0.75-0.80]). The correlation between the static and dynamically determined arch height indices was r = 0.60 (95% CI = 0.53, 0.63), with a mean residual of 0.000 (SD 0.015). INTERPRETATION: A multivariate model generated by plantar parameters during gait was able to predict 60% of the variability in static arch height. This model consisted of variables that appear to be clinically plausible and inform the association between static arch height and dynamic foot posture. Future researchers should address the association between statically and dynamically determined AHI values with lower extremity overuse injuries.

Changes in deep abdominal muscle thickness during common trunk-strengthening exercises using ultrasound imaging.

STUDY DESIGN: Cross-sectional study design. OBJECTIVES: To characterize changes in muscle thickness in the transversus abdominis (TrA) and internal oblique (IO) muscles during common trunk-strengthening exercises, and to determine whether these changes differ based on age. BACKGROUND: Although trunk-strengthening exercises have been found to be useful in treating those with low back pain (LBP), our understanding of the relative responses of the TrA and IO muscles during different exercises is limited. METHODS AND MEASURES: Six commonly prescribed trunk-strengthening exercises were performed by 120 subjects (40 subjects per age group: 18-30, 31-40, and 41-50 years). Ultrasound imaging was used to measure the thickness of the TrA and IO during the resting and contracted state of each exercise. The average thickness of the muscles while in the contracted position was divided by the thickness values in the resting position for each exercise, based on 2 performances of each exercise. Two 3-by-6 repeated-measures analyses of variance were used to determine significant changes in muscle thickness of the TrA and IO, based on age group and exercise performed. RESULTS: For both muscles, the trunk exercise-by-age interaction effect (TrA, P = .358; IO, P = .217) and the main effect for age (TrA, P = .615; IO, P = .219) were not significant. A significant main effect for trunk exercise for both muscles (P<.001) was found. The horizontal side-support (mean +/- SD contracted-rest thickness ratio: TrA, 1.95 +/- 0.69; IO, 1.88 +/- 0.52) and the abdominal crunch (mean +/- SD contracted-rest thickness ratio: TrA, 1.74 +/- 0.48; IO, 1.63 +/- 0.41) exercises resulted in the greatest change in muscle thickness for both muscles. The abdominal drawing-in maneuver (mean +/- SD contracted-rest thickness ratio: TrA, 1.73 +/- 0.36; IO, 1.14 +/- 0.33) and quadruped opposite upper and lower extremity lift (mean +/- SD contracted-rest thickness ratio: TrA, 1.59 +/- 0.49; IO, 1.25 +/- 0.36) exercises resulted in changes in TrA muscle thickness with minimal changes in IO muscle thickness. CONCLUSION: Changes in TrA and IO muscle thickness differed across 6 commonly prescribed trunk-strengthening exercises among healthy subjects without LBP. These differences did not vary by age. This information may be useful for informing exercise prescription.

Effect of using truncated versus total foot length to calculate the arch height ratio.

OBJECTIVE: The purpose of this study was to determine the arch height ratio in a large cohort of subjects as well as to assess the reliability and validity of the foot measurements utilized in the study. METHOD: Eight hundred and fifty subjects, 393 women and 457 men, consented to participate in the study. The dorsal arch height, total foot length, and the truncated foot length were used to calculate two variations of the arch height ratio. In addition to determining within- and between-rater measurement reliability, radiographs were used to establish validity. RESULTS: The truncated arch height ratio can be estimated using the total foot length, unless toe deformities are present in the individual being assessed. All foot measurements had high levels of intra- and inter-rater reliability and the validity of measuring the dorsal arch height while standing with equal weight on both feet was established. CONCLUSIONS: This investigation provides normative values from a large cohort of healthy female and male subjects for two variations of the arch height ratio. The arch height ratio is a reliable and valid measurement that may prove useful to clinicians and researchers for the classification of foot posture.

Effect of wrist and forearm training on linear bat-end, center of percussion, and hand velocities and on time to ball contact of high school baseball players.

This study examined the effects of 12 weeks of wrist and forearm training on linear bat-end velocity (BV), center of percussion velocity (CV), hand velocity (HV), and time to ball contact of high school baseball players. Forty-three baseball players were randomly assigned by a stratified sampling technique to 1 of 2 training groups. Group 1 (n = 23) and group 2 (n = 20) performed the same full-body resistance exercises while training 3 days a week for 12 weeks according to a stepwise periodized model. Group 2 also performed wrist and forearm exercises 3 days a week for 12 weeks. Wrist and forearm strength were measured pre- and posttraining. Linear BV, CV, HV, and time to ball contact were recorded pre- and posttraining by a motion-capture system. A 3 repetition maximum (RM) parallel squat and bench press were measured at baseline and after 4, 8, and 12 weeks of training. Both groups showed statistically significant increases (p < or = 0.01) in linear BV, CV, and HV (m.s(-1) +/- SD) after 12 weeks of training; however, there were no differences between the 2 groups. Both groups statistically increased wrist and forearm strength (p < or = 0.05). Group 2 had statistically greater increases (p < or = 0.05) in 10 of 12 wrist and forearm strength measures than did group 1. Both groups made statistically significant increases in predicted 1RM parallel squat and bench press after 4, 8, and 12 weeks of training; however, there were no differences between groups. These data indicate that a 12-week stepwise periodized training program can significantly increase wrist and forearm strength, linear BV, CV, and HV among high school baseball players. However, increased wrist and forearm strength did not contribute to further increases in linear BV, CV, or HV.

Effect of 12 weeks of wrist and forearm training on high school baseball players.

This study examined the effect of 12 weeks of wrist and forearm training on male high school baseball players (mean age = 15.3 +/- 1.1 years). Participants (N = 43) were tested for 10 repetition maximum (RM) wrist barbell flexion, wrist barbell extension, dominant (D) and nondominant (ND) hand-forearm supination, D and ND forearm pronation, D and ND wrist radial deviation, D and ND wrist ulnar deviation, D and ND grip strength, and a 3RM parallel squat (PS) and bench press (BP). Group 1 (n = 23) and group 2 (n = 20), randomly assigned by a stratified sampling technique, performed the same resistance exercises while training 3 days a week for 12 weeks according to a stepwise periodized model. Group 2 also performed wrist and forearm exercises 3 days a week for 12 weeks to determine if additional wrist and forearm training provided further wrist and forearm strength improvements. All wrist and forearm strength variables were measured before and after 12 weeks of training. The 3RM PS and BP were measured at 0 and after 4, 8, and 12 weeks of training. Both groups significantly increased wrist and forearm strength (kg +/- SD) except 10RM D and ND forearm supination for group 1 (p < 0.05). Group 2 showed statistically greater improvements (p < 0.05) in all wrist and forearm strength variables than did group 1 except for D and ND grip strength. Predicted 1RM (kg +/- SD) PS and BP increased significantly (p < 0.05) after weeks 4, 8, and 12 for both groups. These data indicate that a 12-week stepwise periodized training program can significantly increase wrist, forearm, PS, and BP strength for both groups. Additionally, group 2 had further wrist and forearm strength gains.

Evaluation of the Sports Ankle Rating System in young, athletic individuals with acute lateral ankle sprains.

The purpose of this paper is to introduce the Sports Ankle Rating System and provide the initial validation for its use. As its name implies, this outcomes measurement system is intended for use in assessing the functional outcomes of athletes with ankle injuries. This unique system consists of three distinct instruments: the Quality of Life Measure, the Clinical Rating Score, and the Single Assessment Numeric Evaluation. We began the validation process of the Sports Ankle Rating System with subjects who had sustained lateral ankle sprains because this is the most common injury in sports. The results of this study indicate that the Sports Ankle Rating System is: 1. effective at assessing the impact that an ankle sprain has on an athlete's functional and psychosocial status, 2. responsive to changes in an athlete's ankle-related health status, and 3. valid and reliable as tested.