Chronotype and Social Jetlag Influence Performance and Injury during Reserve Officers' Training Corps Physical Training.

Sleep and circadian rhythms are critically important for optimal physical performance and maintaining health during training. Chronotype and altered sleep may modulate the response to exercise training, especially when performed at specific times/days, which may contribute to musculoskeletal injury. The purpose of this study was to determine if cadet characteristics (chronotype, sleep duration, and social jetlag) were associated with injury incidence and inflammation during physical training. Reserve Officers' Training Corps (ROTC) cadets (n = 42) completed the Morningness/Eveningness Questionnaire to determine chronotype, and 1-week sleep logs to determine sleep duration and social jetlag. Salivary IL-6 was measured before and after the first and fourth exercise sessions during training. Prospective injury incidence was monitored over 14 weeks of training, and Army Physical Fitness Test scores were recorded at the conclusion. Chronotype, sleep duration, and social jetlag were assessed as independent factors impacting IL-6, injury incidence, and APFT scores using ANOVAs, chi-squared tests, and the t-test where appropriate, with significance accepted at p < 0.05. Evening chronotypes performed worse on the APFT (evening = 103.8 ± 59.8 vs. intermediate = 221.9 ± 40.3 vs. morning = 216.6 ± 43.6; p < 0.05), with no difference in injury incidence. Sleep duration did not significantly impact APFT score or injury incidence. Social jetlag was significantly higher in injured vs. uninjured cadets (2:40 ± 1:03 vs. 1:32 ± 55, p < 0.05). Exercise increased salivary IL-6, with no significant effects of chronotype, sleep duration, or social jetlag. Evening chronotypes and cadets with social jetlag display hampered performance during morning APFT. Social jetlag may be a behavioral biomarker for musculoskeletal injury risk, which requires further investigation.

The effect of plyometric training on power and kicking distance in female adolescent soccer players.

The purpose of this study was to measure the effects of low-frequency, low-impact plyometric training on vertical jump (VJ) and kicking distance in female adolescent soccer players. Sixteen adolescent soccer players were studied (age 13.4 ± 0.5 years) across 14 weeks. The control group (general soccer training only) had 6 subjects, and the plyometric training (general soccer training plus plyometric exercise) group had 10 subjects. All subjects were tested for VJ and kicking distance on 3 occasions: pre-test, 7 weeks, and 14 weeks. Data were analyzed using a 2 (Training) × 3 (Test) analysis of variance (ANOVA) with repeated measures on the factor test. No significant difference in kicking distance was found between groups at pre-test (p = 0.688) or 7 weeks (p = 0.117). The plyometric group had significantly greater kicking distance after 14 weeks (p < 0.001). No significant difference in VJ height was found between groups at pre-test (p = 0.837) or 7 weeks (p = 0.108). The plyometric group had a significantly higher VJ after 14 weeks (p = 0.014). These results provide strength coaches with a safe and effective alternative to high-intensity plyometric training. Based on these findings, to increase lower-body power resulting in increased VJ and kicking distance, strength coaches should implement once-weekly, low-impact plyometric training programs with their adolescent athletes.

The effects of adding leucine to pre and postexercise carbohydrate beverages on acute muscle recovery from resistance training.

The present study examined the effects of adding leucine to pre and postexercise carbohydrate beverages on selected markers of muscle damage, delayed-onset muscle soreness (DOMS), and squat performance for up to 72 hours after lower-body resistance training. Seventeen resistance trained men (mean +/- SD age 22.9 +/- 2.9 years) and 3 resistance trained women (mean +/- SD age 21.6 +/- 2.6 years) performed 6 sets of squats to fatigue using 75% of the 1 repetition maximum. Each subject consumed a carbohydrate beverage 30 minutes before and immediately after exercise with or without the addition of 22.5 mgxkg (45 mgxkg total) of leucine in a randomized, double-blind fashion. Serum creatine kinase (CK), lactate dehydrogenase (LDH), and DOMS were analyzed immediately before (TIME1), 24 (TIME2), 48 (TIME3), and 72 (TIME4) hours after exercise. The subjects repeated the squat protocol at TIME4 to test recovery. No differences were observed between groups for squat performance, defined as the total number of repetitions performed during 6 sets of squats, for both TIME1 and TIME4. The addition of leucine did not significantly decrease CK and LDH activity or DOMS. These results suggested that adding leucine to carbohydrate beverages did not affect acute muscle recovery and squat performance during both initial testing and during a subsequent exercise bout 72 hours later in resistance trained subjects.

Concussion-Prevention Strategies Used in National Collegiate Athletic Association Divisions I and II Women's Soccer.

CONTEXT: Whereas much attention has been paid to identifying mechanisms for decreasing concussion rates in women's soccer players, which strategies are currently being used is unknown. In addition, athletic trainers' (ATs') knowledge and beliefs about the efficacy of concussion-prevention practices have not been studied. OBJECTIVES: To evaluate the concussion-prevention strategies being used in National Collegiate Athletic Association Division I and Division II women's soccer and identify the beliefs of certified ATs regarding mechanisms for preventing concussion. DESIGN: Cross-sectional study. SETTING: Online survey. PATIENTS OR OTHER PARTICIPANTS: A total of 223 women's soccer team ATs employed at Division I or II universities. MAIN OUTCOME MEASURE(S): A survey instrument of structured questions and open-ended, follow-up questions was developed to identify the use of cervical-strengthening programs, headgear, and other techniques for preventing concussion. Questions also addressed ATs' beliefs regarding the effectiveness of cervical strengthening, headgear, and mouthguards in concussion prevention. Data were collected via questionnaire in Qualtrics survey software. Descriptive statistics of frequencies and percentages were calculated for close-ended questions. Open-ended questions were evaluated for common themes, which were then reported by response frequency. RESULTS: Cervical strengthening or stability for concussion prevention was reported by 38 (17.12%) respondents; 153 (69.86%) ATs believed that cervical strengthening would aid in concussion prevention. Seventy-eight (35.49%) reported that their players wore headgear. Nineteen (8.76%) believed that soccer headgear prevented concussions; 45 (20.74%) believed that mouthguards prevented concussions. Education in proper soccer technique was reported by 151 (69.59%) respondents. Fourteen (0.06%) respondents cited nutritional strategies for concussion prevention. CONCLUSIONS: Although ATs believed that cervical strengthening could help prevent concussions, few had implemented this strategy. However, the ATs whose teams used headgear outnumbered those who believed that headgear was an effective prevention strategy. Based on our findings, we saw a disconnect among the current use of concussion-prevention strategies, ATs' beliefs, and the available evidence.

Parental stress, family quality of life, and family-teacher partnerships: Families of children with autism spectrum disorder.

BACKGROUND: Reducing parental stress and improving family quality of Life (FQOL) are continuing concerns for families of children with autism spectrum disorder (ASD). Family-teacher partnerships have been identified as a positive factor to help parents reduce their stress and improve their FQOL. However, the interrelations among parental stress, FQOL, and family-teacher partnerships need to be further examined so as to identify the possible paths to help parents reduce their stress and improve their FQOL. The purpose of this study was to examine the interrelations among these three variables. METHOD: A total of 236 parents of school children with ASD completed questionnaires, which included three measures: (a) the Beach Center Family Quality of Life Scale, (b) the Parental Stress Scale, and (c) the Beach Center Family-Professional Partnerships Scale. The structural equation modeling was used to analyze the interrelations among these three variables. RESULTS: Perceived parental stress had a direct effect on parental satisfaction concerning FQOL and vice versa. Perceived family-teacher partnerships had a direct effect on FQOL, but did not have a direct effect on parental stress. However, family-teacher partnerships had an indirect effect on parental stress through FQOL. CONCLUSIONS AND IMPLICATIONS: Reducing parental stress could improve FQOL for families of children with ASD and vice versa. Strong family-teacher partnerships could help parents of children with ASD improve their FQOL and indirectly reduce their stress.

An evaluation of physical fitness parameters for graduate students.

Although graduate physical therapy students are taught the principles of fitness for incorporation into their professional lives, they have difficulty finding the time to implement these principles during graduate school. The authors studied 3 successive classes of graduate physical therapy students at the beginning and ending of their respective programs. They found that the women's percentages of body fat were significantly greater over the period of the study. The men's lower extremity strength decreased at the slower speeds (60 degrees/second), and the women showed increased strength at the higher speeds (180 and 240 degrees/second, respectively). Male grip strength significantly increased over the period of the study. To decrease students' percentages of body fat and increase their strength, the authors asserted that physical therapy students should be allowed more time to participate in fitness activities during their graduate school years.

The effect of acute endurance exercise on lipoproteins: a comparison of the nuclear magnetic resonance technique with the conventional lipid profile in healthy men.

Nuclear magnetic resonance (NMR) of lipoprotein particle size and number may provide greater sensitivity to detecting cardiovascular disease risk compared with the conventional lipid profile in some individuals. The salubrious effect of cardiovascular exercise on blood lipids using the conventional profile is well documented; however, NMR analysis is lacking. The purpose of this study was to examine the effect of a 60-min bout of dynamic exercise on lipoprotein particle size and number as measured by NMR and compare it with the conventional blood lipid profile. Eight active, healthy men (26 ± 5.17 years) ran for 60 min at 70% maximal oxygen uptake on a motor-driven treadmill. Fasting blood samples were drawn at pre-exercise and 5-10 min and 24 h postexercise. The conventional lipid profile showed a significant change in triglycerides (p = 0.019) immediately after exercise with an increase of 22% and a nonsignificant decrease of 13% from baseline after 24 h. The NMR profile showed a significant change in the large high-density lipoprotein particle concentration (p = 0.046) with an increase of 5.8% immediately after exercise, and a decrease of 6.7% at 24 h after exercise. None of the NMR profile changes were significantly different from the baseline value. These data suggest that sensitivity differences between techniques depend on the variable considered; however, they do not warrant concomitant analysis in future studies using this population. Finally, no appreciable favorable or adverse effect was observed in the overall cardiovascular disease risk profile in active, normolipidemic males.

The effect of acute exercise on pistol shooting performance of police officers.

Previous studies indicate that rifle shooting performance while standing is compromised when fatigued. Apprehension of suspects by police officers may involve foot pursuit and firing a weapon from a standing position. The purpose of the current study was to investigate pistol shooting performance in police officers under similar conditions of physical fatigue. Participants (mean age: 30.1 years; 4.4 years of experience as police officer) completed two shooting trials separated by an acute bout of exercise on a cycle ergometer to voluntary exhaustion. Each trial consisted of three rounds of five rapid-fire shots at a target, each round separated by a 15-s rest. Participants' backs were turned to the target between rounds. Despite physical exertion, with an average heart rate of 164 bpm, shooting accuracy (mean distance of the closest 4 shots from the center of the target) and precision (diameter of the tightest 4-shot grouping) remained unchanged on postexercise trials relative to preexercise trials. This suggests that automatic shooting reactions override the adverse consequences of fatiguing exercise on shooting performance.

Sagittal whole-spine magnetic resonance imaging in 750 consecutive outpatients: accurate determination of the number of lumbar vertebral bodies.

OBJECT: When the number of lumbar and sacral vertebrae is being assessed, variations from typical lumbosacral anatomy may confuse the practitioner, potentially leading to significant clinical errors. In this study, the authors describe the statistical variation in lumbar spine anatomy in an outpatient imaging setting, evaluate the potential implications for clinical practice based on the variation in the number of lumbar-type vertebrae identified, and recommend a method for rapidly determining the number of lumbar spine vertebral bodies (VBs) in outpatients referred for lumbar spine MR imaging. METHODS: A total of 762 patients (male and female) who presented with low back-related medical conditions underwent whole-spine MR imaging in an outpatient setting. RESULTS: The high-speed whole-spine evaluation was successful for determining the number of lumbar-type VBs in 750 (98%) of 762 consecutive patients. The sagittal whole-spine 3-T MR imaging system images obtained between the beginning of January 2005 and the end of February 2007 were reviewed. The VBs were counted successively from the level of C-2 inferiorly to the intervertebral disc below the most inferior lumbar-type VB. Numbers of disc herniations were also evaluated in the context of the number of VBs. CONCLUSIONS: One in 5 of these outpatients did not have 5 lumbar-type vertebrae: 14.5% had 6; 5.3% had 4; and 1 (0.13%) had the rare finding of 3 lumbar-type vertebrae. Two-thirds of the individuals with 6 lumbar-type vertebrae were male and two-thirds of the individuals with 4 lumbar-type vertebrae were female. Sagittal whole-spine MR imaging can be performed rapidly and efficiently in the majority of patients (98%), and provides improved accuracy for the determination of the number of lumbar-type VBs. A supplementary coronal MR, Ferguson view radiograph or intraoperative fluoroscopic determination for the presence of lumbosacral transitional vertebrae may add additional information when indicated for clinical treatment or surgical planning.

Traumatic brain injury: a review and high-field MRI findings in 100 unarmed combatants using a literature-based checklist approach.

This study reviewed the literature for the extent of neuroimaging findings in boxers, indicative of traumatic brain injury (TBI) as identified in magnetic resonance imaging (MRI). The study then utilized a systematic checklist approach to assess 100 unselected consecutive 1.5- and 3.0-Tesla MRI examinations of professional unarmed combatants to determine the extent of identifiable TBI findings. The percentage of positive findings and the localization of lesions were quantified using the checklist that included the MRI findings previously reported in the medical literature. Seventy-six percent of the unarmed combatants had at least one finding that may be associated with TBI: 59% hippocampal atrophy, 43% cavum septum pellucidum, 32% dilated perivascular spaces, 29% diffuse axonal injury, 24% cerebral atrophy, 19% increased lateral ventricular size, 14% pituitary gland atrophy, 5% arachnoid cysts, and 2% had contusions. Statistical relationships were found between number of bouts and lateral ventricular size (tau-b = 0.149, p = 0.0489), with years of fighting correlating with the presence of dilated perivascular spaces (tau-b = 0.167, p = 0.0388) and diffuse axonal injury (tau-b = 0.287, p = 0.0013) findings. The improved resolution and increased signal-to-noise ratio on 1.5- and 3.0-Tesla high-field MRI systems defines the range of pathological variations that may occur in professional unarmed combatants. Additionally, the use of a systematic checklist approach insures evaluation for all possible TBI-related abnormalities. This knowledge can be used to anticipate the regions of potential brain pathology for radiologists and emergency medicine physicians, and provides important information for evaluating unarmed combatants relative to their safety and long-term neurocognitive outcome.