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.
Nazli Busra Cigercioglu, Hande Guney-Deniz, Ezgi Unuvar, Filiz Colakoglu, and Gul Baltaci
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.
Francesca A. Harvey and Eric Schussler
Due to increasing rugby participation in the United States, understanding the factors affecting injury rate during participation have gained in importance. The primary objective of this research is to determine the effect of experience on injury rate in collegiate union rugby. Forty-three participants (23 men and 20 women) from the club rugby team participated over the course of one season. Injury data were analyzed by high (3+) and low (<3) seasons of experience. Twenty-four unique injuries were identified for an overall rate of 36.14 injuries per 1,000 exposures. Females with low experience (n = 14) had a rate of 47.34/1,000 exposures; females with high experience (n = 19) had a rate of 34.38/1,000 exposures. Males with low experience (n = 10) had a rate of 28.57/1,000 exposures; males with high experience (n = 13) had a rate of 42.06/1,000 exposures. Inexperienced female participants and experienced male participants showed higher rate of injury during rugby play. Identifying this at-risk group can aid coaches and responsible health care providers in making safer training and game play decisions.
Eric Schussler, Ryan S. McCann, Nicholas Reilly, Thomas R. Campbell, and Jessica C. Martinez
The effect of subconcussive impacts on balance are not well known. The purpose of this study is to determine the effect of subconcussive impacts on dynamic balance over the course of a rugby season. Significant negative linear correlations were found between total peak linear acceleration and dominant leg (r = −.585, p = .046) and bilateral score (r = −.615, p = .033); also between total impacts over 10g and dominant leg (r = −.653, p = .021), nondominant leg (r = −.687, p = .014), and the combined total (r = −.731, p = .007). Results indicate subconcussive impacts may affect dynamic balance over the course of a competitive season of women’s collegiate rugby.
Allison H. Gruber, Shuqi Zhang, Jiahao Pan, and Li Li
The running footwear literature reports a conceptual disconnect between shoe cushioning and external impact loading: footwear or surfaces with greater cushioning tend to result in greater impact force characteristics during running. Increased impact loading with maximalist footwear may reflect an altered lower-extremity gait strategy to adjust for running in compliant footwear. The authors hypothesized that ankle and knee joint stiffness would change to maintain the effective vertical stiffness, as cushioning changed with minimalist, traditional, and maximalist footwear. Eleven participants ran on an instrumental treadmill (3.5 m·s−1) for a 5-minute familiarization in each footwear, plus an additional 110 seconds before data collection. Vertical, leg, ankle, and knee joint stiffness and vertical impact force characteristics were calculated. Mixed model with repeated measures tested differences between footwear conditions. Compared with traditional and maximalist, the minimalist shoes were associated with greater average instantaneous and average vertical loading rates (P < .050), greater vertical stiffness (P ≤ .010), and less change in leg length between initial contact and peak resultant ground reaction force (P < .050). No other differences in stiffness or impact variables were observed. The shoe cushioning paradox did not hold in this study due to a similar musculoskeletal strategy for running in traditional and maximalist footwear and running with a more rigid limb in minimalist footwear.