Characteristics of Injury in Collegiate Rodeo.

OBJECTIVE: The purpose of this study was to investigate injury occurrence sustained by collegiate rodeo athletes during practice and competition. DESIGN: Descriptive epidemiology. SETTING: Eleven National Intercollegiate Rodeo Association member institutions across the United States. PARTICIPANTS: Participants included 264 male and female college rodeo athletes. Athletic trainers (ATs) from each institution reported injury and exposure data using the National Collegiate Athletic Association Injury Surveillance Program. INTERVENTIONS: Institutional ATs reported athlete exposures (AEs) and injuries that occurred from collegiate rodeo practices and competitions. MAIN OUTCOME MEASURE: Injury and AEs from practices and competitions for one college rodeo season were analyzed. Injury rates and ratios were calculated for non-time loss (NTL) and time loss (TL) with 95% confidence intervals (CI). RESULTS: Data revealed a higher proportion of TL than NTL injuries [2.47 vs 1.77 per 1000 AE; injury rate ratios (IRRs) = 1.39; 95% CI: 0.93-2.08]. There was a higher injury rate during competition as compared with practice (10.98 vs 3.09 per 1000 AE; IRR = 3.56; 95% CI: 2.36-5.35), but more injuries were reported in practice (62.2%). CONCLUSIONS: Although the injury rate during rodeo competition was significantly higher than during practice in this study, a greater number of injuries were reported during practice. This indicates all college rodeo athletes can potentially benefit from available medical care.

A Comparison of the Effects of Short-Term Plyometric and Resistance Training on Lower-Body Muscular Performance.

Whitehead, MT, Scheett, TP, McGuigan, MR, and Martin, AV. A comparison of the effects of short-term plyometric and resistance training on lower-body muscular performance. J Strength Cond Res 32(10): 2743-2749, 2018-The purpose of this study was to compare effects of short-term plyometric and resistance training on lower-body muscular performance. A convenience sample of 30 male subjects aged 21.3 ± 1.8 years (height, 177.3 ± 9.4 cm; mass, 80.0 ± 2.6 kg; body fat, 16.1 ± 1.2%) participated in this investigation. Participants were grouped, and they participated in progressive plyometric (PLT) or resistance training (SRT) twice per week for 8 consecutive weeks or a control (CNT) group that did not participate in any training. Performance tests were administered before and after the training period, and it included measures of high-speed muscular strength (standing long jump, vertical jump), low-speed muscular strength (1-repetition maximal back squat), running speed (20-m sprint), and running agility (505 agility test). Analysis of variance followed by post hoc analyses was performed to determine significant differences between the groups. Significance set at p ≤ 0.05 for all analyses. Significant improvements were observed in the PLT group for standing long jump, vertical jump, and 1-repetition maximal back squat compared with the CNT group and for vertical jump as compared with the SRT group. Significant improvements were observed in the SRT group 1-repetition maximal back squat compared with the CNT group. There were no differences observed between any of the groups for the 20-m sprint or the 505 agility test after the training. These data indicate that 8 weeks of progressive plyometric training results in improvements in parameters of high-speed and low-speed muscular strength with no appreciable change in speed or agility. Additionally, the improvement in low-speed muscular strength observed from 8 weeks of progressive plyometric training was comparable to the results observed from 8 weeks of progressive strength training.

Running economy and maximal oxygen consumption after 4 weeks of oral Echinacea supplementation.

The purpose of this investigation was to determine the effects of 4 weeks of oral Echinacea (ECH) supplementation on erythropoietin (EPO), red blood cell (RBC) count, running economy (RE), and VO2max. Twenty-four men aged 24.9 ± 4.2 years, height 178.9 ± 7.9 cm, weight 87.9 ± 14.6 kg, body fat 19.3 ± 6.5% were grouped using a double-blind design and self-administered an 8,000-mg·d(-1) dosage of either ECH or placebo (PLA) in 5 × 400 mg × 4 times per day for 28 days. Blood samples were collected and analyzed for RBCs and EPO using automated flow cytometery and enzyme-linked immunosorbent assay. Maximal graded exercise tests (GXTs) were administered to measure VO2max, RE, and heart-rate responses. Analysis of variance was used to determine statistically significant differences (P ≤ 0.05). The EPO increased significantly in ECH at 7 days (ECH: 15.75 ± 0.64, PLA: 10.01 ± 0.73 mU·ml(-1)), 14 days (ECH: 18.88 ± 0.71, PLA: 11.02 ± 0.69 mU·ml(-1)), and 21 days (ECH: 16.06 ± 0.55, PLA: 9.20 ± 0.55 mU·ml(-1)). VO2max increased significantly in ECH (ECH: 1.47 ± 1.28, PLA: -0.13 ± 0.52%). Running economy improved significantly in ECH as indicated by a decrease in submaximal VO2max during the first 2 stages of the GXT (stage 1: ECH -1.50 ± 1.21, PLA 0.60 ± 1.95%; stage 2: ECH -1.67 ± 1.43, PLA 0.01 ± 1.03%). These data suggest that ECH supplementation results in significant increases in EPO, VO2max, and running economy.

Comparison of Post-Activation Potentiating Stimuli on Jump and Sprint Performance.

Post-activation potentiation (PAP) is a phenomenon characterized by improved muscle performance based on the previous contractile activity of the muscle. The purpose of this study was to determine the effect of different potentiating stimuli on jump and sprint performance in 13 resistance trained, college-aged men and women. After determining back squat 1 repetition max, subjects returned for testing on separate days to complete one of four interventions (dynamic resistance, weighted plyometric, isometric, or control) in a randomized order. A standardized warmup was performed, followed by a baseline countermovement jump (CMJ) and 20m sprint. Following warm-up and baseline measurements, subjects performed one of the four experimental conditions. CMJ and 20m sprint measurements were completed again at 20-seconds, 4, 8, 12, 16, and 20-minutes. Results revealed significantly faster 0-20m sprint times (p < .05) at the 4, 8, 12, 16, and 20-minute time points compared to baseline and 20-second time points. Significantly faster 0-20m sprint times (p < .05) were also shown for the squat intervention compared to control at 4-minutes, the plyometric and squat intervention compared to control at 8-minutes, the isometric intervention compared to control at 12 and 16-minutes, and the isometric intervention compared to the squat at 20-minutes. These findings indicate that while all PAP stimuli utilized can be effective at improving sprint performance, specific optimal time points may exist.

Six weeks of oral Echinacea purpurea supplementation does not enhance the production of serum erythropoietin or erythropoietic status in recreationally active males with above-average aerobic fitness.

The purpose of this study was to investigate the effect of 6 weeks of oral Echinacea purpurea supplementation on serum erythropoietin (EPO) and erythropoietic status. Twenty-four males (mean ± SE; age = 25.2 ± 1.4 years, height = 178.1 ± 1.4 cm, body mass = 78.1 ± 1.6 kg, body fat = 12.7 ± 0.9%, maximal oxygen uptake = 52.9 ± 0.9 mL·kg-1·min-1) were randomly grouped using a matched-pair, double-blind design and self-administered 8000 mg·day-1 of either E. purpurea (n = 12) or placebo (n = 12) for 42 consecutive days. Blood samples were collected prior to supplementation (day 0) and every 2 weeks during the supplementation period (days 14, 28, and 42) and were analyzed for EPO, red blood cell count, hemoglobin concentration, hematocrit, mean corpuscular volume, and mean corpuscular hemoglobin concentration. Separate 2 × 4 (group × time) factorial ANOVA with repeated measures on time were used to determine statistical differences with significance set at p ≤ 0.05. There were no significant interaction, group, or time effects observed for EPO or erythropoietic status markers for any of the measurement points (p ≤ 0.05). The present study indicated that 6 weeks of oral E. purpurea supplementation in recreationally active males with above average aerobic fitness did not enhance EPO or erythropoietic status. These findings are in contrast with previous reports of E. purpurea supplementation in untrained participants with average fitness levels, but consistent with observations in trained endurance athletes.

Comparison of glycerol and water hydration regimens on tennis-related performance.

PURPOSE: To compare glycerol and water hyperhydration and rehydration on tennis related skill and agility performance. METHODS: Eleven male subjects completed two counter-balanced, double-blind trials. Each trial consisted of three phases: 1). hyperhydration with or without glycerol (1.0 g.kg/(-1)) over 150 min, 2). 120 min of exercise-induced dehydration (EID), and 3) rehydration with or without glycerol (0.5 g.kg(-1)) over 90 min. After each phase, subjects performed 5- and 10-m sprint tests, a repeated-effort agility test, and tennis skill tests. RESULTS: Glycerol (G) hyperhydration significantly increased fluid retention by approximately 900 mL over the placebo (P) (P

Use of a pretest strategy for physical therapist assistant programs to predict success rate on the national physical therapy exam.

This study investigated a pretest strategy that identified physical therapist assistant (PTA) students who were at risk of failure on the National Physical Therapy Examination (NPTE). Program assessment data from five cohorts of PTA students (2005-2009) were used to develop a stepwise multiple regression formula that predicted first-time NPTE licensure scores. Data used included the Nelson-Denny Reading Test, grades from eight core courses, grade point average upon admission to the program, and scores from three mock NPTE exams given during the program. Pearson correlation coefficients were calculated between each of the 15 variables and NPTE scores. Stepwise multiple regression analysis was performed using data collected at the ends of the first, second, and third (final) semesters of the program. Data from the class of 2010 were then used to validate the formula. The end-of-program formula accounted for the greatest variance (57%) in predicted scores. Those students scoring below a predicted scaled score of 620 were identified to be at risk of failure of the licensure exam. These students were counseled, and a remedial plan was developed based on regression predictions prior to them sitting for the licensure exam.

The effects of a daily stretching protocol on passive glenohumeral internal rotation in overhead throwing collegiate athletes.

INTRODUCTION/PURPOSE: Shoulder dysfunction and injury are common in throwing athletes. Loss of internal rotation has been correlated to shoulder pathologies. The purpose of this study was to assess the effects of a stretching protocol on passive internal rotation. The purpose of this study was assess the effects of a stretching protocol on passive internal rotation motion in the throwing shoulders of collegiate baseball players. STUDY DESIGN: Pre-Post, intervention, using a within subjects comparison of a convenience sample. METHODS: Glenohumeral internal rotation and external rotation of the throwing and non-throwing shoulders of NCAA Division I baseball players were measured using a universal goniometer. Determinations were made as to the degree of Glenohumeral Internal Rotation Deficit (GIRD) in the throwing shoulder. A daily (5 days per week), 12-week posterior capsule stretching program was administered. Post-stretching internal rotation and external rotation measures were again obtained. The coaches and athletic trainers of the included team monitored the players for shoulder injuries and innings of training/competition lost due to shoulder injuries during the 12 week intervention. RESULTS: A significant increase in range of motion was found for dominant arm internal rotation (IR) and total range of motion (TOT) following the stretching program. No statistically significant improvement in range of motion was found for external rotation (ER), non-throwing arm internal rotation (NDIR), non-throwing arm external rotation (NDER), and non-throwing arm total motion (NDTOT). CONCLUSIONS: Implementation of a posterior capsule stretching program may be helpful to facilitate increased passive internal rotation range of motion at the glenohumeral joint. Further research should be performed using a control group not receiving the stretching program in order to more completely establish the impact of stretching on measures of passive glenohumeral range of motion. LEVEL OF EVIDENCE: 1b.

The effect of 4 wk of oral echinacea supplementation on serum erythropoietin and indices of erythropoietic status.

The purpose of this investigation was to determine whether echinacea supplementation results in alterations of erythroid growth factors and erythropoietic status. Twenty-four men age 24.9 +/- 4.2 y, height 1.7 +/- 0.8 m, weight 87.9 +/- 14.6 kg, and 19.3% +/- 6.5% body fat were grouped using a double-blind design and self- administered an 8000-mg/d dose of either echinacea (ECH) or placebo (PLA) in 5 x 400 mg x 4 times/d for 28 d. Blood samples were collected and analyzed for red blood cells (RBCs), hematocrit (Hct), hemoglobin (Hb), mean corpuscular volume, mean corpuscular hemoglobin content, prostaglandin E2, ferritin, erythropoietin (EPO), interleukin 3 (IL-3), and granulocyte-macrophage-colony-stimulating factor using automated flow cytometry and ELISA. ANOVA was used to determine significant differences (P ? 0.05). EPO was greater (P < 0.001) in ECH at Days 7, 14, and 21 and reflected a 44%, 63%, and 36% increase, respectively. IL-3 was greater (P = 0.011) in ECH at Days 14 and 21, which indicated a 65% and 73% increase, respectively. These data indicate that ECH supplementation resulted in an increase in EPO and IL-3 but did not significantly alter RBCs, Hb, or Hct.

The effect of glycerol on torque, electromyography, and mechanomyography.

The purpose of this investigation was to determine the effect of hyperhydration on the electromyographic (EMG) and mechanomyographic (MMG) responses during isometric and isokinetic muscle actions of the biceps brachii. Eight (22.1 +/- 1.8 years, 79.5 +/- 22.8 kg) subjects were tested for maximal isometric, submaximal isometric, and maximal concentric isokinetic muscle strength in either a control (C) or hyperhydrated (H) state induced by glycerol ingestion while the EMG and MMG signals were recorded. Although fluid retention was significantly greater during the H protocol, the analyses indicated no change in torque, EMG amplitude, EMG mean power frequency (MPF), MMG amplitude, or MMG MPF with hyperhydration. These results indicated that glycerol-induced fluid retention does not affect the torque-producing capabilities of a muscle, the impulses (EMG) going to a muscle, or muscular vibrations (MMG). It has been suggested that EMG and MMG can be used as direct electrical/mechanical monitoring, which could be presented to trainers and athletes; however, before determining the utility of these signals, the MMG and EMG responses should be examined under a variety of conditions such as in the present study.

Effect of moderate dehydration on torque, electromyography, and mechanomyography.

The purpose of the present investigation was to test the hypotheses that the mechanomyographic (MMG) signal would be affected by hydration status due to changes in the intra- and extracellular fluid content (which could affect the degree of fluid turbulence), changes in the filtering properties of the tissues between the MMG sensor and muscle, and changes in torque production that may accompany dehydration. Ten subjects (age 22.5 +/- 1.6 years) were tested for maximal isometric (MVC), submaximal isometric (25, 50, and 75%MVC), and maximal concentric isokinetic muscle strength of the biceps brachii in either a euhydrated or dehydrated state while the electromyographic (EMG) and MMG signals were recorded. Separate three-way and two-way ANOVAs indicated no change in torque, EMG amplitude, EMG mean power frequency (MPF), MMG amplitude, and MMG MPF with dehydration. The lack of dehydration effect suggests that MMG may be more reflective of the intrinsic contractile processes of a muscle fiber (torque production) or the motor control mechanisms (reflected by the EMG) than the tissues and fluids surrounding the muscle fiber.