Enora Le Flao, Andrew W. Pichardo, Sherwin Ganpatt, and Dustin J. Oranchuk
Context: Neck size and strength may be associated with head kinematics and concussion risks. However, there is a paucity of research examining neck strengthening and head kinematics in youths. In addition, neck training is likely lacking in youth sport due to a perceived inadequacy of equipment or time. Objective: Examine neck training effects with minimal equipment on neck strength and head kinematics following chest perturbations in youth athletes. Design: Single-group, pretest–posttest case series. Setting: Athlete training center. Participants: Twenty-five (14 men and 11 women) youth soccer athletes (9.8 [1.5] y). Intervention: Sixteen weeks of twice-weekly neck-focused resistance training utilizing bands, body weight, and manual resistance. Main Outcome Measures: Head kinematics (angular range of motion, peak anterior–posterior linear acceleration, and peak resultant linear acceleration) were measured by an inertial motion unit fixed to the apex of the head during torso perturbations. Neck-flexion and extension strength were assessed using weights placed on the forehead and a plate-loaded neck harness, respectively. Neck length and circumference were measured via measuring tape. Results: Neck extension (increase in median values for all: +4.5 kg, +100%, P < .001; females: +4.5 kg, +100%, P = .002; males: +2.2 kg, +36%, P = .003) and flexion (all: +3.6 kg, +114%, P < .001; females: +3.6 kg, +114%, P = .004; males: +3.6 kg, +114%, P = .001) strength increased following the intervention. Men and women both experienced reduced perturbation-induced head pitch (all: −84%, P < .001). However, peak resultant linear acceleration decreased in the female (−53%, P = .004), but not male (−31%, P = 1.0) subgroup. Preintervention peak resultant linear acceleration and extension strength (R 2 = .21, P = .033) were the closest-to-significance associations between head kinematics and strength. Conclusions: Young athletes can improve neck strength and reduce perturbation-induced head kinematics following a 16-week neck strengthening program. However, further research is needed to determine the effect of improved strength and head stabilization on concussion injury rates.
Jackson M. Howard, Bonnie C. Nicholson, Michael B. Madson, Richard S. Mohn, and Emily Bullock-Yowell
Due to demand for high performance inside and outside of the classroom, student-athletes are a unique subsection of college students. Researchers have focused on investigating protective factors, which may enhance student-athlete well-being and academic success in higher education and reduce athlete burnout. The current study examined grit as a mediator between parenting behaviors and academic success, mental health outcomes, and burnout in higher education among National Collegiate Athletic Association Division I and Division II student-athletes (N = 202). Overparenting behaviors were negatively associated with psychological autonomy granting, mental health outcomes, and athlete burnout. Psychological autonomy granting behaviors were positively associated with grit and negatively associated with mental health outcomes and athlete burnout. Student-athlete grit mediated the relationship between overparenting behaviors and mental health outcomes. Clinical implications include improving student-athlete parent onboarding protocol; student-athlete psychoeducation; and preventative outreach and health promotion among athletes, athletic staff, and university practitioners. In summary, these findings suggest that parenting behaviors and grit are factors that require more attention in fostering student-athlete success.
John Kuzmeski, Gillian Weir, Travis Johnson, Matthew Salzano, and Joseph Hamill
This study investigated the differences between 5 commonly used methods to calculate leg stiffness over a range of running velocities. Thirteen male, habitually rearfoot, recreational runners ran on a force instrumented treadmill for a 5-minute running session. Each session consisted of 30-second intervals at 6 progressively faster speeds from 2.5 m·s−1 through 5.0 m·s−1 with each interval speed increasing by 0.5 m·s−1. Two-way within-factors repeated-measures analyses of variance were used to evaluate leg stiffness and length. A one-way repeated-measures analysis of variance was used to evaluate the slope of each trend line of each model across speeds. Pearson correlations were used to compare the relationship between the different computational methods. The results indicated that the direct stiffness methods increased with speed whereas the indirect stiffness methods did not. The direct methods were strongly correlated with each other as were the indirect methods. However, there were no strong correlations between the direct and indirect methods. These differences can be mostly attributed to how each individual stiffness method calculated leg length. It is important for researchers to understand these differences when conducting future studies and comparing past studies.
Karlee Burns, Ryan Tierney, and Jane McDevitt
Clinical Question: In individuals with posttraumatic headache following concussion, what impact does medication have? Clinical Bottom Line: Prescription medications may be beneficial for those suffering posttraumatic headache following concussion by decreasing headache symptoms and improving cognitive function, though long-term outcomes were similar between those taking and not taking medications.
Paul A. Cacolice and Corinne M. Ebbs
Clinical Question: What is the effect of CT intervention on the stress and arousal levels of undergraduate students? Clinical Bottom Line: There is Level A–B evidence showing that the use of therapy dogs decreases stress and elevates arousal in female undergraduate students, with little evidence available for other populations.
Courtney J. DeFeo, Nathan Morelli, and Matthew C. Hoch
Clinical Scenario: Postural control deficits are one of the most common impairments associated with sport-related concussion. The Modified Balance Error Scoring System (mBESS) is one of the current standard clinical measures for assessing these deficits; however, it is dependent upon observer-rated measurements. Advancements in inertial measurement units (IMUs) lend themselves to be a viable option in objectifying postural control assessments, such as the mBESS. Clinical Question: Are IMU-based measures of the mBESS more effective than observer-rated measures of the mBESS in identifying patients with sport-related concussion? Summary of Key Findings: Following a systematic search, three studies were included. One study compared observer-rated measures of the Balance Error Scoring System and mBESS to instrumented measures of both tests and determined that the instrumented mBESS had the highest diagnostic accuracy. The results of the second study determined that IMU-based measures were successful in both classifying group and identifying task errors. The final study found that using IMUs increased sensitivity of the mBESS, specifically the double-limb stance, to group classification. Clinical Bottom Line: Instrumentation of the mBESS using IMUs provides more objective and sensitive measures of postural control in patients with SRC. Strength of Recommendation: Due to the consistent, good-quality evidence used to answer this critically appraised topic, the grade of A is recommended by the Strength of Recommendation Taxonomy.
Clinical Scenario: Resistance training (RT) programs promote skeletal muscle hypertrophy through the progressive physiological stress applied to an individual. Currently, the vast majority of studies regarding the hypertrophic response to RT have focused on either sedentary or untrained individuals. This critically appraised topic focuses on the hypertrophic response to high- and low-load RT in resistance-trained men. Clinical Question: In experienced male weightlifters, does high-load RT lead to greater increases in muscle mass than low-load RT? Summary of Key Findings: Six studies met the inclusion criteria, while 4 studies were included in the analysis. Each of the 4 studies showed that low-load RT elicited hypertrophic gains similar to high-load RT when sets were taken to failure. Three of the studies were not volume equated, indicating a dose–response relationship between training volume-load and skeletal muscle hypertrophy. One of the studies was volume equated, indicating that skeletal muscle hypertrophy could be achieved at levels comparable to those observed in high-load protocols as a result of high levels of metabolic stress and the concomitant recruitment of high-threshold motor units that can occur during fatiguing contractions. Clinical Bottom Line: Evidence suggests that low-load training produces hypertrophic gains similar to those observed in high-load RT protocols when sets are taken to failure in resistance-trained men. Strength of Recommendation: There is moderate to strong evidence to suggest that low-load RT elicits hypertrophic gains similar to those observed in high-load RT protocols when sets are taken to failure in resistance-trained men.
Jeffrey J. Martin, Erin E. Snapp, E. Whitney G. Moore, Lauren J. Lieberman, Ellen Armstrong, and Staci Mannella
Youth with visual impairments (VIs) often experience unique barriers to physical activity compared with their sighted peers. A psychometrically sound scale for assessing barriers to physical activity for youth with VI is needed to facilitate research. The purpose of this study was to confirm the ability of the previously identified three-factor structure of the Physical Activity Barriers Questionnaire for youth with Visual Impairments (PABQ-VI) to produce scores considered to be valid and reliable that perform equally well across age, VI severity, and gender. Our results supported the three-factor structure and that the PABQ-VI produces scores considered valid and reliable. Mean, variance, and correlation differences were found in personal, social, and environmental barriers for age and VI severity, but not gender. Researchers can use the PABQ-VI to test and evaluate ways to reduce barriers for this population.
Elif Turgut, Gozde Yagci, and Volga Bayrakci Tunay
Context: Knowledge on how to utilize a kinetic chain approach in foot and ankle rehabilitation is important. Objective: The aim of this study was to investigate the immediate effects of hip-focused neuromuscular exercise on foot pronation and single-leg neuromuscular control. Design: Cross-over study. Setting: University laboratory. Participants: This cross-over study included 44 asymptomatic volunteers with foot pronation. Interventions: All participants performed (1) a hip-focused neuromuscular exercise and (2) a sham exercise in randomized order. Main Outcome Measures: Foot pronation was assessed by the navicular drop test, and lower-extremity neuromuscular control was assessed by the Modified Star Excursion Balance Test and frontal plane projection angle during single-leg squat before and after the experiments. Results: Navicular drop test scores were significantly lower after the hip-focused neuromuscular exercise than after the sham exercise (mean difference [95% CI] = 2.84 [−1.08 to 6.77], P = .003). Modified Star Excursion Balance Test scores in the anterior (P = .008), posteromedial (P = .04), and posterolateral (P < .001) directions were significantly increased after hip-focused neuromuscular exercise. No statistically significant condition × time interaction was found for the frontal plane projection angle (P > .05). However, a main effect of time (P = .003) indicated that less dynamic knee valgus occurred during single-leg squat after both experiments. Conclusions: Hip-focused neuromuscular exercise produced immediate alterations in foot pronation and dynamic balance. Thus, the hip-focused neuromuscular exercise may be used to control foot posture in foot rehabilitation integrated with a kinetic chain approach and could be an effective prevention and treatment strategy.