Identification of Neuromusculoskeletal Variables Associated With Injury Risk and Performance in High School Athletes.

This study involves a test - re-test design. Subjects will be tested in their physical performance. These measures include a general assessment of joint mobility, muscle strength, motor coordination, and performance assessment utilizing functional movement screens. The physical examination is similar to a physical examination performed clinically in sports performance testing and also in the practice of Physical Therapy. The initial baseline measure will provide objective scores that can be utilized to assess for change over time. Additional information to be gathered includes demographic information on the subject including age, previous injury history, and level of exposure to physical performance training. These variables are associated with injury risk and also impact the potential for change with physical performance training. In addition, information on mental factors including stress, fear of failure, and burnout will be collected. It is hypothesized that these variables also factor into athletic performance. It is not known how these variables impact injury risk. Information on training load will be gathered weekly during the training period. Training load has a direct impact on muscle performance, and is hypothesized to impact injury risk. The subjects will be re-tested at the end of the training period to measure changes in physical performance and injury risk.

Project Procedures

Study population: High school athletes, ages 14 to 18, who are participating in an organized sports training program. The target subject enrollment is 250 high school athletes.

Inclusion criteria will be athletes who have completed a pre-participation sports physical, are enrolled in a sports elective or a member of a sports team, and have volunteered to participate in the study providing both verbal and written consent.

Exclusion criteria for participation include athletes who have not submitted a pre-participation sports physical to the high school training staff, student athletes who are currently suffering from an acute neuromusculoskeletal injury with restrictions on athletic participation, an athlete who has undergone surgery within a 3 month period of the program start date, an athlete who presents with a cardiovascular condition that would exclude exercise participation (systolic BP \> 180, diastolic BP \> 100), or athletes who are currently pregnant.

Study Methodology

Participants will complete a self-report questionnaire collecting demographic data including age, gender, primary and secondary sport activity, and previous injury history. Participants will also complete the Perceived Stress Scale to measure self-appraised stress, the Sports Mental Training Questionnaire to measure mental preparation skills, and the Athlete Burnout Questionnaire to assess emotional/physical exhaustion at the beginning and end of the 8 week program to assess psychological stressors associated with sport participation that may impact motivation to participate and perceived internal training load.

The structured physical performance assessment will include functional movement testing, motor coordination testing, joint mobility screen, muscle strength testing, and agility performance testing. Video analysis will be included with the functional movement testing utilizing software to assess reliability of the neuromuscular impairment screen.

Research project specific measures:

Functional movement testing includes:

1. Forward flexion/hinge 2. Standing trunk rotation 3. Bilateral squat 4. Forward lunge 5. Lateral lunge 6. Lower extremity functional reach test 7. Upper extremity movement pattern (shoulder mobility test) 8. Quadruped trunk rotary stability test

Mobility testing includes:

1. Ankle mobility testing (DF, PF, IV, EV, first ray extension) 2. Hip mobility testing (flexion, extension, abduction, IR, ER) 3. Cervical mobility testing (flexion, extension, side bending, rotation, flexion rotation 4. Thoracic mobility testing (seated trunk rotation) 5. Shoulder mobility testing (flexion with scapular mobility assessment, abduction with scapular mobility assessment, IR, ER) 6. Elbow mobility testing (flexion, extension, supination, pronation) 7. Wrist mobility (flexion, extension)

Muscle strength testing:

1. Hip strength (flexion, extension, abduction, ER, IR) 2. Knee strength (flexion, extension) 3. Ankle strength (PF, IV, EV) 4. Shoulder strength (IR, ER, AB) 5. Scapular strength (middle trap, lower trap) 6. Elbow strength (flexion, extension)

Performance testing:

1. Jump testing (bilateral long jump, unilateral jump, drop box jump) 2. Upper extremity closed chain reach testing 3. Shuttle run

Intrinsic and Extrinsic training load will be recorded weekly for subjects participating in the research study. Data will be utilized to calculate the training load associated with the school based strength and conditioning training program.

• Number of participants who experience a musculoskeletal sports related injury. [Time frame: End of study (1 year)]
• Intrinsic training load as measured by perceived effort of the training session (Rate of Perceived Exertion Scale) [Time frame: Weekly, for 8 weeks during the strength and conditioning training program]