Carolina Digital Repository (University of North Carolina at Chapel Hill), 2005
The authors compared leg stiffness (K VERT), muscle activation, and joint movement patterns betwe... more The authors compared leg stiffness (K VERT), muscle activation, and joint movement patterns between 11 men and 10 women during hopping. Physically active and healthy men and women performed continuous 2-legged hopping at their preferred rate and at 3.0 Hz. Compared with men, women demonstrated decreased K VERT ; however, after the authors normalized for body mass, gender differences in K VERT were eliminated. In comparison with men, women also demonstrated increased quadriceps and soleus activity, as well as greater quadriceps-to-hamstrings coactivation ratios. There were no significant gender differences for joint movement patterns (p > .05). The relationship between the observed gender differences in muscle recruitment and the increased risk of anterior cruciate ligament injury in women requires further study. Keywords ACL; quadriceps; coactivation; hop; jump Females' anterior cruciate ligament (ACL) injury rates are 2.0 to 9.7 times greater than are males' ACL injury rates (
The influence of cutaneous and joint receptors on the quadriceps femoris torque-velocity relation... more The influence of cutaneous and joint receptors on the quadriceps femoris torque-velocity relationship was assessed with the Kin-Com (Chattecx, Inc., Hixson, TN) isokinetic dynamometer. Twenty-four females (age = 21 ± 1.4 years, ht = 163 + 6.0 cm, wt = 60 ± 7.6 kg) were divided into two groups and tested with the force pad placed either proximally or distally on the leg. Three concentric and eccentric contractions were performed at 25, 50, 75, 100, 125, 150, 175 and 200's-1 on 2 separate days with an anesthetic applied to the skin under the force pad on 1 of the 2 days. An ANOVA was performed on peak torque with trend analyses performed on velocity factors. The results indicate the cutaneous and knee joint receptors do not affect the quadriceps femoris concentric or eccentric torque-velocity relationships, F(7,154)-1.61. Furthermore, the results revealed significant linear, F(1,154)-161.14, and quadratic trends, F(1,154) = 25.85, for concentric and eccentric peak torque, respectively. Thus, the concentric torque-velocity relationship is best described by a linear relationship rather than the classic curvilinear relationship. Conversely, the eccentric relationship is best described by the classic curvilinear relationship. These results suggest that adequate assessment of muscular torque production requires testing at multiple velocities.
Journal of Orthopaedic & Sports Physical Therapy, May 1, 1997
, J.H. (1997). A trend analysis of the in vivo quadriceps femoris angle specific torque-velocity ... more , J.H. (1997). A trend analysis of the in vivo quadriceps femoris angle specific torque-velocity relationship. Journal of Orthopedic and Sports Physical Therapy, 25:316-322. ***Note: Figures may be missing for this format of the document ***Note: Footnotes and endnotes indicated with parentheses
Separately, both physical activity and virtual reality can attenuate pain sensitivity in healthy ... more Separately, both physical activity and virtual reality can attenuate pain sensitivity in healthy adults. What is unknown is whether virtual reality combined with physical activity (active virtual reality) could have a greater hypoalgesic effect compared to non-active virtual reality distraction (passive virtual reality engagement). Objective: The purpose of this study was to determine whether playing physically active virtual reality games exert a greater hypoalgesic effect than a non-active virtual reality game. Methods: Participants (n = 36) played three different active virtual reality games (Beat Saber, Holopoint, and Hot Squat) and one non-active virtual reality game (Relax Walk) for 15 min on four different visits. During gameplay, participants wore accelerometers on the thigh, wrist, and waist to measure movement intensity and quantity. Pressure pain thresholds were measured on the forearm and thigh immediately prior to gameplay (pretest) and immediately following each gaming...
Objectives: The purpose of this study was to determine the following: (1) the level of physical a... more Objectives: The purpose of this study was to determine the following: (1) the level of physical activity (PA) achieved during commercial active virtual reality (VR) games, and (2) which active VR games elicit higher enjoyment levels in young, healthy adults. Materials and Methods: Thirty-six participants completed four study sessions, each devoted to playing one of the following head-mounted display VR games for 15 minutes: Beat Saber (BS), Holopoint (HP), Hot Squat (HS), and Relax Walk VR. PA intensity measures included percentage of heart rate reserve (%HRR), ratings of perceived exertion (RPE), and accelerometry. Enjoyment was measured with the Physical Activity Enjoyment Scale (PACES) following each gaming session. Mixed-model analysis of variances were used to analyze the outcome measures. Results: The analyses showed that HS elicited significantly higher %HRR and RPE than BS, HP, and Relax Walk. HS was the only game to reach moderate intensity via %HRR. Accelerometer data showed that time in whole-body moderate-to-vigorous physical activity (MVPA) for HS was significantly greater than HP, which was greater than BS and Relax Walk. Also, males exhibited significantly more whole-body and upper limb MVPA compared with females during gameplay. BS and HP were rated significantly more enjoyable than HS and Relax Walk. Conclusions: Results from this study suggest that active VR games can elicit varying degrees of PA intensity levels in young healthy adults, with HS eliciting moderate intensity activity. The games rated highest in enjoyment required mostly arm movement and a perceived light exertion. ClinicalTrials: NCT04221139.
Our purpose was to establish normal patterns and relationships of stability using the Biodex Stab... more Our purpose was to establish normal patterns and relationships of stability using the Biodex Stability System. The design of this study used both nonexperimental and quasi-experimental methods. All testing was performed in a university sports medicine laboratory. Nineteen healthy subjects (8 males, 11 females, age = 24.4 +/- 4.2 years; wt = 70.5 +/- 20 kg; ht = 171.2 +/- 11.7 cm) with no history of lower extremity injury participated in this study. For data analysis, the medial/lateral stability index (MLSI), anterior/posterior stability index (APSI), overall stability index (OSI), and time-in-balance scores were recorded. Multiple regression revealed that APSI and MLSI significantly contributed to the OSI, with the APSI accounting for 95% of the OSI variance. Additionally, the percentage of time spent between 0 degrees and 5 degrees from level was significantly greater than the time spent between 6 degrees and 10 degrees , 11 degrees and 15 degrees , and 16 degrees and 20 degrees ....
International Journal of Athletic Therapy and Training, 2018
Facemask removal is an emergency skill to gain airway access in football athletes with potential ... more Facemask removal is an emergency skill to gain airway access in football athletes with potential cervical injury. While facemask removal performance has been reported in experienced athletic trainers, initial skill acquisition is undocumented. Therefore, the purpose was to document skill development in novice athletic training students. After instruction, student performance was documented during six consecutive facemask removal trials. From first to last trials, there were significant improvements in time, confidence, and rating of perceived exertion. Induced head motion did not improve. While overall skill performance began to approximate previously reported norms, improvements in success rate, consistency, and motion are needed.
This study evaluated the effectiveness of ibuprofen in treating delayed onset muscle soreness (DO... more This study evaluated the effectiveness of ibuprofen in treating delayed onset muscle soreness (DOMS) of the elbow flexors when taken prior to and following exercise. Twenty subjects received either 2,400 mg/day ibuprofen or a placebo four times per day. Subjects performed intense eccentric exercise of the elbow flexors to elicit DOMS. Concentric and eccentric peak torque production against an isokinetic resistance of 0.52 radls, range of motion at the elbow, and subjective soreness of the elbow flexors were measured. ANOVA indicated no significant group-by-time interaction for concentric peak torque, eccentric peak torque, or pain. A significant interaction was revealed for range of motion. There was a significant difference within each group's ROM but no interaction between groups. It was concluded that the use of 2,400 mg/day ibuprofen prior to and following intense eccentric exercise was no more effective than a placebo in treating DOMS of the elbow flexors.
NLIKE MOST sports injuries, mild guidelines stems from a lack of empirical data head injury (MHI)... more NLIKE MOST sports injuries, mild guidelines stems from a lack of empirical data head injury (MHI) or concussion can to support them. Unfortunately, most of the be catastrophic if not managed ap-grading scales and guidelines are based on propriately. Despite the seriousness anecdotal information or clinical experience. of these injuries, the literature on MHI in Experts agree that most of the proposed prosport is rather limited. tocols are safe and that athletes are placed at Several notable articles on sport related little risk if the guidelines are closely adhered concussion have been published in the last to. However, none of the grading scales and 25 years, but few have provided evidence return-to-play guidelines are followed with any consistency, and none have 3.7 4
We examined employer importance ratings of 35 employee characteristics in the collegiate, sports ... more We examined employer importance ratings of 35 employee characteristics in the collegiate, sports medicine clinic, and high school settings and made comparisons among these settings. All prospective employers were sent a survey. Of the 472 surveys mailed, 282 (60%) were returned, with a sample error rate of 1.9%. All prospective employers listed on the NATA position vacancy notices from January 1, 1994 to October 1, 1994. Employers were asked to rate 35 employee characteristics as "not important" " minimally important," " important." or "very important." Additionally, employers chose 1 of 15 job descriptors that best identified their position vacancy. These 15 descriptors were then categorized into collegiate, sports medicine clinic, and high school settings. Discriminant analysis and analysis of variance procedures were used to determine if the 35 employee characteristics differed across the 3 settings. The discriminant analysis produced 2 sig...
Carolina Digital Repository (University of North Carolina at Chapel Hill), 2005
The authors compared leg stiffness (K VERT), muscle activation, and joint movement patterns betwe... more The authors compared leg stiffness (K VERT), muscle activation, and joint movement patterns between 11 men and 10 women during hopping. Physically active and healthy men and women performed continuous 2-legged hopping at their preferred rate and at 3.0 Hz. Compared with men, women demonstrated decreased K VERT ; however, after the authors normalized for body mass, gender differences in K VERT were eliminated. In comparison with men, women also demonstrated increased quadriceps and soleus activity, as well as greater quadriceps-to-hamstrings coactivation ratios. There were no significant gender differences for joint movement patterns (p > .05). The relationship between the observed gender differences in muscle recruitment and the increased risk of anterior cruciate ligament injury in women requires further study. Keywords ACL; quadriceps; coactivation; hop; jump Females' anterior cruciate ligament (ACL) injury rates are 2.0 to 9.7 times greater than are males' ACL injury rates (
The influence of cutaneous and joint receptors on the quadriceps femoris torque-velocity relation... more The influence of cutaneous and joint receptors on the quadriceps femoris torque-velocity relationship was assessed with the Kin-Com (Chattecx, Inc., Hixson, TN) isokinetic dynamometer. Twenty-four females (age = 21 ± 1.4 years, ht = 163 + 6.0 cm, wt = 60 ± 7.6 kg) were divided into two groups and tested with the force pad placed either proximally or distally on the leg. Three concentric and eccentric contractions were performed at 25, 50, 75, 100, 125, 150, 175 and 200's-1 on 2 separate days with an anesthetic applied to the skin under the force pad on 1 of the 2 days. An ANOVA was performed on peak torque with trend analyses performed on velocity factors. The results indicate the cutaneous and knee joint receptors do not affect the quadriceps femoris concentric or eccentric torque-velocity relationships, F(7,154)-1.61. Furthermore, the results revealed significant linear, F(1,154)-161.14, and quadratic trends, F(1,154) = 25.85, for concentric and eccentric peak torque, respectively. Thus, the concentric torque-velocity relationship is best described by a linear relationship rather than the classic curvilinear relationship. Conversely, the eccentric relationship is best described by the classic curvilinear relationship. These results suggest that adequate assessment of muscular torque production requires testing at multiple velocities.
Journal of Orthopaedic & Sports Physical Therapy, May 1, 1997
, J.H. (1997). A trend analysis of the in vivo quadriceps femoris angle specific torque-velocity ... more , J.H. (1997). A trend analysis of the in vivo quadriceps femoris angle specific torque-velocity relationship. Journal of Orthopedic and Sports Physical Therapy, 25:316-322. ***Note: Figures may be missing for this format of the document ***Note: Footnotes and endnotes indicated with parentheses
Separately, both physical activity and virtual reality can attenuate pain sensitivity in healthy ... more Separately, both physical activity and virtual reality can attenuate pain sensitivity in healthy adults. What is unknown is whether virtual reality combined with physical activity (active virtual reality) could have a greater hypoalgesic effect compared to non-active virtual reality distraction (passive virtual reality engagement). Objective: The purpose of this study was to determine whether playing physically active virtual reality games exert a greater hypoalgesic effect than a non-active virtual reality game. Methods: Participants (n = 36) played three different active virtual reality games (Beat Saber, Holopoint, and Hot Squat) and one non-active virtual reality game (Relax Walk) for 15 min on four different visits. During gameplay, participants wore accelerometers on the thigh, wrist, and waist to measure movement intensity and quantity. Pressure pain thresholds were measured on the forearm and thigh immediately prior to gameplay (pretest) and immediately following each gaming...
Objectives: The purpose of this study was to determine the following: (1) the level of physical a... more Objectives: The purpose of this study was to determine the following: (1) the level of physical activity (PA) achieved during commercial active virtual reality (VR) games, and (2) which active VR games elicit higher enjoyment levels in young, healthy adults. Materials and Methods: Thirty-six participants completed four study sessions, each devoted to playing one of the following head-mounted display VR games for 15 minutes: Beat Saber (BS), Holopoint (HP), Hot Squat (HS), and Relax Walk VR. PA intensity measures included percentage of heart rate reserve (%HRR), ratings of perceived exertion (RPE), and accelerometry. Enjoyment was measured with the Physical Activity Enjoyment Scale (PACES) following each gaming session. Mixed-model analysis of variances were used to analyze the outcome measures. Results: The analyses showed that HS elicited significantly higher %HRR and RPE than BS, HP, and Relax Walk. HS was the only game to reach moderate intensity via %HRR. Accelerometer data showed that time in whole-body moderate-to-vigorous physical activity (MVPA) for HS was significantly greater than HP, which was greater than BS and Relax Walk. Also, males exhibited significantly more whole-body and upper limb MVPA compared with females during gameplay. BS and HP were rated significantly more enjoyable than HS and Relax Walk. Conclusions: Results from this study suggest that active VR games can elicit varying degrees of PA intensity levels in young healthy adults, with HS eliciting moderate intensity activity. The games rated highest in enjoyment required mostly arm movement and a perceived light exertion. ClinicalTrials: NCT04221139.
Our purpose was to establish normal patterns and relationships of stability using the Biodex Stab... more Our purpose was to establish normal patterns and relationships of stability using the Biodex Stability System. The design of this study used both nonexperimental and quasi-experimental methods. All testing was performed in a university sports medicine laboratory. Nineteen healthy subjects (8 males, 11 females, age = 24.4 +/- 4.2 years; wt = 70.5 +/- 20 kg; ht = 171.2 +/- 11.7 cm) with no history of lower extremity injury participated in this study. For data analysis, the medial/lateral stability index (MLSI), anterior/posterior stability index (APSI), overall stability index (OSI), and time-in-balance scores were recorded. Multiple regression revealed that APSI and MLSI significantly contributed to the OSI, with the APSI accounting for 95% of the OSI variance. Additionally, the percentage of time spent between 0 degrees and 5 degrees from level was significantly greater than the time spent between 6 degrees and 10 degrees , 11 degrees and 15 degrees , and 16 degrees and 20 degrees ....
International Journal of Athletic Therapy and Training, 2018
Facemask removal is an emergency skill to gain airway access in football athletes with potential ... more Facemask removal is an emergency skill to gain airway access in football athletes with potential cervical injury. While facemask removal performance has been reported in experienced athletic trainers, initial skill acquisition is undocumented. Therefore, the purpose was to document skill development in novice athletic training students. After instruction, student performance was documented during six consecutive facemask removal trials. From first to last trials, there were significant improvements in time, confidence, and rating of perceived exertion. Induced head motion did not improve. While overall skill performance began to approximate previously reported norms, improvements in success rate, consistency, and motion are needed.
This study evaluated the effectiveness of ibuprofen in treating delayed onset muscle soreness (DO... more This study evaluated the effectiveness of ibuprofen in treating delayed onset muscle soreness (DOMS) of the elbow flexors when taken prior to and following exercise. Twenty subjects received either 2,400 mg/day ibuprofen or a placebo four times per day. Subjects performed intense eccentric exercise of the elbow flexors to elicit DOMS. Concentric and eccentric peak torque production against an isokinetic resistance of 0.52 radls, range of motion at the elbow, and subjective soreness of the elbow flexors were measured. ANOVA indicated no significant group-by-time interaction for concentric peak torque, eccentric peak torque, or pain. A significant interaction was revealed for range of motion. There was a significant difference within each group's ROM but no interaction between groups. It was concluded that the use of 2,400 mg/day ibuprofen prior to and following intense eccentric exercise was no more effective than a placebo in treating DOMS of the elbow flexors.
NLIKE MOST sports injuries, mild guidelines stems from a lack of empirical data head injury (MHI)... more NLIKE MOST sports injuries, mild guidelines stems from a lack of empirical data head injury (MHI) or concussion can to support them. Unfortunately, most of the be catastrophic if not managed ap-grading scales and guidelines are based on propriately. Despite the seriousness anecdotal information or clinical experience. of these injuries, the literature on MHI in Experts agree that most of the proposed prosport is rather limited. tocols are safe and that athletes are placed at Several notable articles on sport related little risk if the guidelines are closely adhered concussion have been published in the last to. However, none of the grading scales and 25 years, but few have provided evidence return-to-play guidelines are followed with any consistency, and none have 3.7 4
We examined employer importance ratings of 35 employee characteristics in the collegiate, sports ... more We examined employer importance ratings of 35 employee characteristics in the collegiate, sports medicine clinic, and high school settings and made comparisons among these settings. All prospective employers were sent a survey. Of the 472 surveys mailed, 282 (60%) were returned, with a sample error rate of 1.9%. All prospective employers listed on the NATA position vacancy notices from January 1, 1994 to October 1, 1994. Employers were asked to rate 35 employee characteristics as "not important" " minimally important," " important." or "very important." Additionally, employers chose 1 of 15 job descriptors that best identified their position vacancy. These 15 descriptors were then categorized into collegiate, sports medicine clinic, and high school settings. Discriminant analysis and analysis of variance procedures were used to determine if the 35 employee characteristics differed across the 3 settings. The discriminant analysis produced 2 sig...
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