DETERMINACIÓN DE LA EMISIÓN DE PARTÍCULAS CONTAMINANTES

This methodological consideration section will review methodology previously utilized to evaluate similar parameters compared to those chosen for this study. This section will also provide a rationale for each of the methodologies chosen for this study. A detailed description of the protocol and methodologies specific to this study is provided in chapter 3.

2.4.1 Injury Surveillance and Exposure Tracking

Injury surveillance and exposure tracking for the present study is based on the University of Pittsburgh Injury Prevention Initiative.22 Lower extremity musculoskeletal injury history was collected utilizing self-report.22 Each athlete was responsible for disclosing their lower extremity musculoskeletal injury history, spanning the course of their lifetime.22 Self-report has been utilized successfully by the Neuromuscular Research Laboratory for the purposes of collecting musculoskeletal injury history from Special Operations Forces Operators.22 Injury surveillance occurred over the course of one athletic season. At the completion of each athletic season, the athletic trainer responsible for the care of teams included in the study will reported on all lower extremity musculoskeletal injuries suffered over the course of the season. These methods for injury surveillance have been utilized by the NCAA Injury Surveillance System with success.27 By collecting musculoskeletal injury data from each of the athletic trainers responsible for the treatment and care of the teams included in the study, there is an increased likelihood of receiving valid and reliable injury data. Both the University of Pittsburgh Injury Initiative and the NCAA Injury Surveillance System collect musculoskeletal injury data that includes injury type, location, sublocation, mechanism of injury, onset, and time lost.27 Exposures were collected on a weekly basis, with email surveys sent to each athletic trainer responsible for the care of the teams included in the study. Athlete exposures were collected as either a “yes” or “no” for each potential day of participation for each athlete. If an athlete participated for any amount of time during a potential day of participation it will be counted as a “yes” or one exposure. 27

If an athlete did not participation, for any amount of time during a potential day of participation, it will be counted as a “no” or zero exposure. 27

NCAA Injury Surveillance System. Collecting hours of athlete participation leads to increased reporting error. 27 These methods have been utilized successfully over the course of five years with the University of Pittsburgh Injury Prevention Initiative.22

2.4.2 Range of Motion and Flexibility Assessment

Assessment of lower extremity range of motion and flexibility allows for an establishment of the individual range of motion and flexibility of the muscles of the ankle, knee, and hip. The range of motion and flexibility tests chosen for this study include active ankle joint dorsiflexion mobility, ankle dorsiflexion, straight leg raise, and active knee extension. The range of motion and flexibility tests chosen for this study isolate the specific lower extremity muscles theorized to be related to lower extremity musculoskeletal injury. The flexibility and range of motion tests chosen for this study are also typical of the tests utilized by clinicians when caring for athletes. All lower extremity range of motion and flexibility testing procedures, chosen for this particular study, are based on pre-established procedures. 14, 9761, 62, 64 8, 8336, 61, 62, 82, 83 Intra-rater and inter- rater reliability has been conducted within the Neuromuscular Research Laboratory and the ICCs are between 0.51-0.99 with SEMs between 0.97-13.00. The testing positions for each specific lower extremity muscle have been chosen based on previous research that has established that these specific testing positions provide the most valid measurements of lower extremity range of motion and strength. 14, 9761, 62, 64 8, 8336, 61, 62, 82, 83

2.4.3 Isometric Strength Assessment

Assessment of lower extremity isometric strength allows for an establishment of the individual strength of the muscles of the lower extremity including the muscles of the ankle, knee, and hip. The isometric strength tests chosen for this study include, ankle dorsiflexion, ankle plantarflexion, ankle eversion/inversion, knee flexion/extension, hip abduction/adduction, and hip internal/external rotation.46 Isometric strength is a better choice to isolate these specific muscles when compared to isokinetic strength, because of the inability of isokinetic strength to differentiate between the strength of the individual lower extremity muscles and gross lower extremity strength.46 Traditionally, the equipment associated with isokinetic strength testing is non-movable, expensive, and requires extensive tester training in order to utilize the equipment appropriately to assess the strength of the lower extremity. Using the handheld dynamometer, which has been chosen for this particular study, allows for the measures of isometric strength to be portable, as well as being more applicable to a clinical assessment of an athlete. The handheld dynamometer, as alluded to earlier, is also a better choice for isolating the lower extremity muscles as opposed to the Biodex which is better for large gross lower extremity movement strength assessment.46 All lower extremity isometric strength testing procedures, chosen for this particular study, are based on grade five manual muscle testing pre-established procedures.46 Intra-rater and inter-rater reliability has been conducted within the Neuromuscular Research Laboratory and the ICCs are between 0.20-0.98 with SEMs between 1.53-9.75. The testing positions for each specific lower extremity muscle have been chosen based on previous research that has established that these specific testing positions provide the greatest isometric contraction and isolate the individual lower extremity muscles appropriately.46

2.4.4 Postural Stability Assessment

Single leg balance performed on a force plate is a commonly accepted measure of static postural stability.40 This protocol is both reliable and valid, as well as being sensitive enough to detect the standard deviation of ground reaction forces in three planes (anterior/posterior, medial/lateral, and vertical) during the 10 second trial.40 This test is performed in a single-leg position (barefooted) under eyes-open and eyes-closed conditions. During the duration of the test the subject is asked to remain as still as possible with non-test leg raised to about the level of the tested ankle without touching the tested limb and while maintaining hands on hips.40 The static postural stability protocol, chosen for this particular study, has established reliability (ICC = 0.71-0.94; SEM = 0.19-3.40 Newtons).40

Several methods have been proposed for use in determining dynamic postural stability, including the Star Excursion Balance Test and Y-Balance Test.90, 99 Dynamic postural stability as measured by the Dynamic Postural Stability Index is both a reliable and valid measure of dynamic postural stability.90, 99 The Dynamic Postural Stability Index is a jump task in which the sensitivity and objectivity of the test is strong enough to appropriately calculate three separate component scores in the anterior/posterior, medial/lateral, and vertical directions, as well as a composite score of these three component scores.90, 99 The jump task associated with the Dynamic Postural Stability Index is an anterior/posterior jump off two-feet, terminating with a single leg balance and subsequent stabilization maintained for a total of five seconds.90, 99 The jump is normalized to body height in order to standardize across subjects.90, 99 The dynamic postural stability protocol, chosen for this particular study, has established reliability previously tested within the Neuromuscular Research Laboratory (ICC = 0.86; SEM = 0.01).90, 99