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Browsing by Author "Goforth, Michael W."

Now showing 1 - 5 of 5
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    An Analysis of Catcher's Mask Performance to Attenuate Head Accelerations
    Shain, Kellen Saul (Virginia Tech, 2010-04-21)
    The goals of this study were to measure the ability of catcher's masks to attenuate head accelerations upon impact with a baseball, and to compare these head accelerations to established injury thresholds for concussions. Testing involved using a pneumatic cannon to shoot baseballs at an instrumented (3-2-2-2 accelerometer array) Hybrid III headform (a 50th percentile male head and neck) with and without a catcher's mask on the head. The ball speed was controlled from approximately 26.8 – 35.8 m/s (60 – 80 mph) and regulation NCAA baseballs were used. Peak linear resultant acceleration was 140 – 180 g without a mask and 16 – 30 g with a mask over the range of balls speeds investigated. Peak angular resultant acceleration was 19500 – 25700 rad/sec2 without a mask and 2250 – 3230 rad/sec2 with a mask. The Head Injury Criterion was 93 – 181 without a mask and 3 – 13 with a mask and the Severity index was 110 – 210 without a mask and 3 – 15 with a mask. Catcher's masks reduced head acceleration metrics by approximately 85% when baseballs were impacted with just the headform. Head accelerations with a catcher's mask were substantially lower than contemporary injury thresholds, yet evidence indicates that baseball impacts to the mask still result in concussions.
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    Effects of Fatigue & Gender on Peroneal Reflexes After Ankle Inversion
    Wilson, Erin Lawall (Virginia Tech, 2005-05-02)
    An estimated 23,000 ankle injuries occur every day in the U.S. Ankle sprains account for 85% of all ankle injuries and inversion ankle sprains account for 85% of all ankle sprains. There is growing evidence that suggests gender and fatigue may increase the risk for inversion ankle sprains. Investigating the effects of fatigue and gender on peroneal reflex response after ankle inversion may help explain the differences in sprain rates with fatigue and gender. Therefore, the purpose of this study was to investigate the effects of fatigue and gender on peroneus brevis and peroneus longus reflexes after ankle inversion. A "trap-door" platform was used to elicit peroneal reflexes from sixteen males and fifteen females by suddenly inverting the ankle to 20°. Five unfatigued peroneal reflex measurements were performed before and after a fatigue protocol that attempted to fatigue the ankle evertors over 12 minutes to 75% of the unfatigued MVC torque. Results showed that reflex delay was not affected by fatigue, gender, or their interaction. PL reflex amplitude was not affected by fatigue or gender but was affected by their interaction. Results showed that PL reflex amplitude decreased by 11.3% in males and increased 22.1% in females with fatigue. A secondary analysis attempted to rule out extraneous factors that could have contributed to the differences in reflex response, but no experimental explanations were found. The differences in PL reflex amplitude were attributed to biomechanical, physiological, and anatomical differences between males and females.
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    The Etiology of Impact Related Concussion for Catchers and Umpires in Baseball
    Beyer, Jeffrey Andrew (Virginia Tech, 2011-04-27)
    The information presented herein attempts to quantify the conditions surrounding concussive impacts from foul tips to the masks of catchers and umpires in baseball. Media reports of such occasions were researched on video and pitch speed data from the Pitch F/X system recorded to suggest speeds and locations at which impacts occur. To evaluate mask performance, a pneumatic-wheel, electric-motor driven pitching machine was utilized to shoot baseballs at the instrumented head of a Hybrid III dummy. Head accelerations were calculated from a 3-2-2-2 accelerometer array to allow for comparisons of linear and angular kinematics. 6 common masks (2-piece traditional-style and 1-piece hockey-style) were tested at 7 locations at 60 mph to determine the severity of each location. The center-eyebrow and chin locations were further tested at 84 mph. Speed and location data were used to evaluate a large sample of 25 masks to explore possible performance differences between manufacturer models, mask types and cage styles. The results of this study showed no significant difference between hockey-style and traditional-style mask performance. Titanium caged masks, although lighter than their steel counterparts, experienced higher linear accelerations. However, all masks experienced linear and angular accelerations well below commonly accepted injury thresholds. Yet, concussive injury has still occurred in the players and umpires that wear these masks. The work presented here can be used to help better understand these thresholds and influence the design, construction and evaluation of a new generation of masks that decrease the risk of concussions to the wearer.
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    Implementation of Blood Flow Restriction for Injury Rehabilitation in the Athletic Training Setting
    Ziyout, Hisham A.J.; Hulver, Matthew W.; Rockwell, Michelle S.; Goforth, Michael W. (Virginia Tech, 2019-05-06)
    Rehabilitation after an injury in athletics is a major concern for athletes and athletic trainers. The athletic trainer is responsible for returning the injured athlete back to participation as fast and safely as possible. Since it is typically unsafe to apply heavy loads, such as weights, to an extremity after an injury, atrophy tends to occur to the injured area. Blood flow restriction is a modality that is fairly new in the United States. Research has shown that blood flow restriction used during low-intensity (20-30% 1RM) loads significantly increases muscular strength and hypertrophy compared to high-intensity loads (>70% 1RM) without blood flow restriction (Pope et al, 2013). The purpose of this project was to document preliminary experiences with blood flow restriction in a collegiate athletics setting and disseminate practical information about blood flow restriction to practicing athletic trainers across the United States. Blood flow restriction has been shown to be a safe and effective resource for clinicians when helping a patient rehabilitate from surgery and return to participation faster, although minimal clinical trial evidence is available. When blood flow restriction was incorporated as a treatment modality within the Department of Intercollegiate Athletics at Virginia Tech, positive effects on injury rehabilitation and patient compliance were observed. Further research on blood flow restriction during injury rehabilitation is needed in order to help practicing athletic trainers make the best evidence-based decisions when utilizing this modality with their patient.
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    Tibial Acceleration and Shock Attenuation in Female and Male Distance Runners at Different Levels of Body Weight Unloading
    Leatham, Cheyenne Liahona (Virginia Tech, 2024-05-28)
    Running popularity has led to a rise in chronic lower limb injuries resulting from cumulative loading. Many of these injuries are tibial stress fractures. Tibial accelerometers are commonly used to measure tibial stress and may even be predictive of injury at the distal limb. Lower body positive pressure (LBPP) treadmills have become increasingly popular amongst athletes and practitioners to prevent and treat lower limb injuries by reducing effective body weight (BW) through mechanical support. The purpose of this thesis is to investigate if BW unloading affects tibial acceleration (TA) and shock attenuation. Twelve trained distance runners (Sex: 6 males and 6 females; Age: 18-30 years) were recruited for this study. TA was measured through two Blue Trident, IMeasureU step units located at the distal tibiae. A STATSports Apex unit was also used to measure acceleration at the superior trunk and calculate shock attenuation for each limb. It was found that BW unloading had no discernable effect on mean peak TA and shock attenuation, bone stimulus, or contact time, regardless of running speed. However, a significant relationship was observed between running speed and both mean peak TA and bone stimulus where an increase in speed led to an increase in TA and bone stimulus. Furthermore, running speed did not affect shock attenuation or contact time. In conclusion, BW unloading did not alter gait kinematics in trained distance runners.