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.
Nazli Busra Cigercioglu, Hande Guney-Deniz, Ezgi Unuvar, Filiz Colakoglu, and Gul Baltaci
Purpose: Repetitive and asymmetric movements in tennis can result in biomechanical adaptation in shoulder joint. The aim of this study was to investigate the differences in shoulder range of motion (ROM), strength, and functional performance tests between the dominant and nondominant shoulders, as well as to identify gender differences in junior tennis players. Methods: Forty-two junior tennis players (age mean: 11.3 [1.2] y, body mass index 18.3 [2.4] kg/m2) were included in the study. Shoulder internal rotation (IR), external rotation (ER) ROM, and total ROM, IR and ER isokinetic strength and closed kinetic chain upper-extremity stability, seated medicine ball throw used, grip hold tests were applied bilaterally. Paired sample t test and Student t test were used to compare the differences. Results: ER ROM was greater, while IR ROM and total ROM were lower on the dominant shoulder (all P values < .05). Nineteen players had glenohumeral IR deficit (IR ROM difference >13°). The players had a greater ER strength on the dominant side and similar IR strength between shoulders. There was significant difference in seated medicine ball throw results between the dominant and nondominant sides (P < .001). The mean distance for bilateral seated medicine ball throw was 377.02 (85.70) m, and closed kinetic chain upper-extremity stability results were calculated as a mean of 15.85 (1.72) touches. Differences between the genders: total ROM of the dominant shoulder was higher in female players (P = .045), the IR PT/BW at 60°/s angular speed was higher in male players’ dominant shoulder (P = .030), and closed kinetic chain upper-extremity stability performance was higher in male players (P = .019). Conclusions: Adolescent tennis players demonstrated differences in strength, ROM, and functional performance results between the dominant and nondominant shoulders. Gender differences were also seen in the aforementioned parameters in junior tennis players. Determining these differences may improve our understanding of sport-specific shoulder joint adaptations in tennis.
Hitoshi Oda, Yasushi Sawaguchi, Hiroshi Kunimura, Taku Kawasaki, and Koichi Hiraoka
This study examined whether the current movement follows the previous movement and whether this process is enhanced by somatosensory stimulation or is gated while retrieving and using the memory of the previously practiced target end point. Healthy humans abducted the index finger to a previously practiced target (target movement) or abducted it freely without aiming at the target (nontarget movement). The end point of the nontarget movement had a positive correlation with the previous nontarget movement only when somatosensory stimulation was given during the previous movement, indicating that the current nontarget movement follows the previous nontarget movement with somatosensory stimulation. No conclusive evidence of whether this process is gated by retrieving and using the memory of the previously practiced target was found.
Michal Vágner, Zdeněk Bílek, Karel Sýkora, Vladimír Michalička, Lubomír Přívětivý, Miloš Fiala, Adam Maszczyk, and Petr Stastny
The aim of this study was to find the effect of holographic sight (HS) on short-distance shooting accuracy and precision during static and high-intensity dynamic actions. Twenty policemen (31 ± 2.2 years, 85.6 ± 6.1 kg, and 181.9 ± 4.4 cm) performed five shots in the 10-s limit under the static condition for 20 m and dynamic condition 15–5 m, and after 4 × 10 m sprint action, both with fixed sight (FS) and HS. The analysis of variance post hoc test revealed that HSstatic had higher shouting accuracy than FSstatic, FSdynamic, and HSdynamic (p = .03, p = .0001, and p = .0001, respectively) and FSdynamic had lower precision than FSstatic, HSstatic, and HSdynamic (p = .0003, p = .0001, and p = .01, respectively) in vertical sway. The HS for rifles has improved the accuracy of static shooting and vertical sway precision of dynamic shooting.
David P. Schary and Carolina Lundqvist
In reaction to the COVID-19 pandemic, restrictive policies altered student-athletes’ academic and athletic life. Sparse research has investigated the pandemic’s effect on student-athlete mental health in terms of both negative (e.g., depression, anxiety) and positive (e.g., well-being, quality of life) dimensions. This study explored the effect of the COVID-19 pandemic on well-being and quality of life among National Collegiate Athletic Association Division I student-athletes at different stages of their collegiate career. Ninety-nine student-athletes (M age = 19.7 years, SD = 1.5) completed assessments on their mental health. Regression analysis revealed experiences directly related to COVID-19 did not affect general well-being or quality of life, but anxiety, depression, and significant insomnia did. Social well-being was lower for student-athletes closer to graduation (e.g., juniors, seniors), independent of reported anxiety and depression levels. These findings highlight the importance of psychosocial support, particularly in times of crisis, and indicate that tailored support might be beneficial at later stages of the collegiate years.
Mary D. Fry, Candace M. Hogue, Susumu Iwasaki, and Gloria B. Solomon
Psychological coping skills in sport are believed to be central to athlete performance and well-being. This study examined the relationship between the perceived motivational climate in elite collegiate sport teams and player psychological coping skills use. Division I athletes (N = 467) completed a questionnaire examining their perceptions of how caring, task-, and ego-involving their teams were and their use of sport specific psychological coping skills (i.e., coping with adversity, peaking under pressure, goal setting/mental preparation, concentration, freedom from worry, confidence/achievement motivation, and coachability). Structural equation modeling revealed positive relationships between perceptions of a task-involving climate and confidence/achievement motivation (β = 0.42) and goal setting/mental preparation (β = 0.27). Caring climate perceptions were positively associated with coachability (β = 0.34). These findings illustrate how encouraging athletes and coaches to create a caring, task-involving climate may facilitate athletes’ use of psychological coping skills and set athletes up to perform their best and have a positive sporting experience.
Nathan Harrison, W. Zach Garrett, and Mark K. Timmons
Context: Fatigue of the scapular stabilizing muscles resulting from repeated arm motion has been reported to alter scapular kinematics, which could result in shoulder pathology, especially impingement. Objective: This study aimed to examine the effects of fatigue of the serratus anterior muscle on scapular kinematics, specifically, decrease scapular posterior tilt and upward scapular rotation during arm elevation. Design: Repeated measures. Setting: Laboratory. Participants: Thirty participants were included in the investigation. Interventions: Scapular kinematics and shoulder strength were measured before and immediately following a serratus anterior fatigue protocol. Main Outcome: Scapular 3-dimensional position during arm elevation. Results: No difference in upward rotation of the scapula between prefatigue and postfatigue conditions (ascending: P = .188; descending: P = .798). Scapular posterior tilt decreased during arm elevation following the fatigue protocol between 60° and 90° and 90° and 120° of arm elevation during the ascent (P = .004) and the descent (P = .013). Fatigue by arm elevation angle interaction was found for clavicular elevation during the ascent (P = .050) between 90° and 120° of arm elevation. Scapular internal rotation increased during the ascent (P = .027). There was no difference in clavicular protraction between the prefatigue and postfatigue conditions (ascending: P ≤ .001; descending: P ≤ .001). Conclusion: Fatigue of the serratus anterior decreases posterior scapular tilt and greater clavicular elevation and scapular internal rotation at higher arm elevation angles. These findings are consistent with the scapular kinematic patterns associated with shoulder pain. Improving serratus anterior endurance might delay the changes in scapular kinematics associated with repeated arm motion and shoulder injury mechanisms.
Brice Picot, Romain Terrier, Nicolas Forestier, François Fourchet, and Patrick O. McKeon
The Star Excursion Balance Test (SEBT) is a reliable, responsive, and clinically relevant functional assessment of lower limbs’ dynamic postural control. However, great disparity exists regarding its methodology and the reported outcomes. Large and specific databases from various population (sport, age, and gender) are needed to help clinicians when interpreting SEBT performances in daily practice. Several contributors to SEBT performances in each direction were recently highlighted. The purpose of this clinical commentary is to (a) provide an updated review of the design, implementation, and interpretation of the SEBT and (b) propose guidelines to standardize SEBT procedures for better comparisons across studies.