Sport Sciences and Health Research

Introduction: The return to sport after Anterior Cruciate Ligament Reconstruction (ACLR) is among the main issues encountered by rehabilitation medicine, injured athletes, and coaches. A main factor preventing safe return to sports is a biomechanical asymmetry between the limbs during reconstruction, which plays a significant role in the risk of re-injury. Accordingly, injury-related biomechanical changes were systematically examined in individuals with ACLR as performed functional tasks. Materials and Methods: Articles relevant to biomechanical asymmetries between (ACLR & uninjured) limbs in English were searched in the Google Scholar, Science Direct, PubMed MEDLINE, and Scopus databases without time limit until 2021, using the following keywords: “Anterior cruciate ligament reconstruction”, “ACL reconstruction”, “biomechanical”, “Kinetic”, “Kinematic”, and “Asymmetry”. Results: In total, 122 articles were found, of which 18 met the inclusion (PRISMA) criteria. Most of the kinetic and kinematic parameters were observed in the intervals of 3, 6, 9, 12, and 18 months after ACLR between the athletes’ vertical Ground Reaction Force (vGRF), peak hip abduction moment, peak knee valgus angle, peak knee flexion moment and angle, during the functional tasks; also changes were detected in the articles up to 28 months, although research in this area was limited. Conclusion: The present systematic review suggested that biomechanical variables may vary among the limbs of patients with ACLR, between 18 and over 28 months. Accordingly, an asymmetry between the limbs increases the risk of re-injury. Therefore, a better understanding of the biomechanics of the limbs in the time intervals after ACLR can provide a safer and sooner return to sports activities.

Introduction: The present study aimed to compare hip muscle resistance training with and without feedback on trunk, pelvis, and lower extremity motions in frontal and sagittal planes among active females with dynamic valgus. Materials and Methods: Twenty-Nine active females (Mean±SD age: 22.8±2.4 years, height: 1.70±0.6 m, weight: 69±7.1 kg) were randomly assigned to a hip muscle resistance training with feedback group (n=15) or a hip muscle resistance training without feedback group (n=14). Both training programs lasted 6 weeks (3 sessions/week). The peak angles of lateral trunk flexion, contralateral pelvic drop, hip flexion, knee flexion, and valgus during single-leg drop landing and single-leg vertical drop jump were assessed in the research participants at baseline and 6 weeks post-training. Unipodal functional screening tests were captured with two standard digital video cameras. Results: After 6 weeks, significant differences were observed in knee valgus and lateral trunk flexion, contralateral pelvic drop, and knee flexion angles, i.e., compared between hip muscle resistance training with feedback and hip muscle resistance training without feedback (P<0.05), except for non-dominant leg hip flexion in single-leg vertical drop jump (P>0.05). Conclusion: In the explored active females with dynamic valgus, hip muscle resistance training with feedback seems to be better at improving trunk, pelvis, and lower extremity motions in frontal and sagittal planes, compared to hip muscle resistance training without feedback; however, no significant difference was observed concerning hip flexion during single-leg vertical drop jump between the study groups.

Introduction: Children and adolescents with Developmental Coordination Disorder (DCD) usually fail to understand spatial awareness and motor timing. The present study assessed Rhythmic Auditory Stimulations (RAS) and Simple Auditory Stimulations (SAS) to facilitate the learning of timing in sequential motor task and recorded the results of their relative and absolute timing errors.  Materials and Methods: 56 male students aged 9-12 years with DCD in Neyshabur city were selected by diagnosing with the following tools: Teacher Motor Inventory, Parental Developmental Coordination Disorder Questionnaire, Movement Assessment Battery for Children-Second (MABC-2 movement test), spatial-visual memory assessment, intelligence assessment, RT test, and biopsychological health status evaluation. Then, they were divided into RAS, SAS, control group 1 (visual), and control group 2. Moreover, a pretest score was performed. Next, the training protocol was presented in 10 blocks of 5 attempts and the acquisition test was performed. Finally, the retention and transfer tests were performed after 48 hours and 10 minutes, respectively.  Results : Based on the obtained results, a significant difference was observed between the visual stimulation group and the RAS and SAS groups in relative and absolute timing components (P≤0.05). However, no significant difference was reported between the rhythmic, SAS, and visual-auditory stimulation groups in relative and absolute timing variables (P˃0.05). Conclusion: Finally, no significant difference was observed between the RAS and simple stimulations although the graphs displayed the effect of the first stimulation more than that of the second one.

Introduction: Prescribing the Adrenergic beta-Antagonists is very common in treating cardiovascular diseases. The aim of this study was to compare the effects of aerobic training in patients with coronary artery disease, prescribed two different types of beta-blockers (selective and non- selective) on the patient's lipid profile (Lipoproteins) and FBS (Blood Glucose). Materials and Methods : Sixty patients with coronary artery disease, aged 45-65 years, were compared in two groups of selective (n=36) and non-selective (n=24) users of beta-blockers. The training program consisted of 8 weeks of aerobic exercise on the treadmill (3 sessions per week, about 50 minutes per session, with an intensity of 40% to 60% of the heart rate reserve). Each study patient’s lipid profile and FBS level were obtained before the onset of the study and after the end of the intervention. The collected data were analyzed using repeated-measures Analysis of Variance (ANOVA). Results: In the selective group, lipid profile and FBS did not significantly change. In the non-selective group, FBS and triglyceride levels were significantly reduced after the intervention; however, HDL, LDL, and total cholesterol levels were not significantly changed (P>0.05). Conclusion: The results of this study showed that aerobic training in patients with CAD who used non-selective beta-blockers has more positive effects.

Introduction: The present study aimed to compare the effects of 3 school-based physical exercises with different levels of cognitive engagement on executive functions.  Materials and Methods: In total, 47 students aged 13-14 years were randomly divided into 3 groups, as follows: the Integrated Physical and Cognitive (IPC) exercise, peer physical exercise group (with the same physical challenge), and control group (the routine physical education program). A Continuous Performance Test (CPT), the N-back test, and the Stroop test were used to evaluate executive functions in pretest and posttest.  Results: The obtained results indicated that the IPC group significantly improved more than the other groups on the executive functions. Accordingly, physical exercise with a higher cognitive load benefitted both speed and accuracy on cognitive tasks significantly more than the same physical activity alone.  Conclusion: Therefore, in the integrated physical and cognitive exercise, the cognitive and physiological effects of this training style interact with each other; therefore, their beneficial effects can be gradually increased, while interventions that only focus on the physical dimension would be less effective in promoting cognitive functions.

Introduction: Iliotibial Band Syndrome (ITBS) is among the most common injuries in distance runners. Thus, the present study investigated the effect of a special strengthening exercise program for abductor’s muscles according to NSCA protocol, on pain reduction and lower extremity function improvement among elite distance runners with ITBS. Materials and Methods: The subjects of the present study were 32 elite distance runners who were randomly divided into two groups of control and experimental (n=16/group). The experimental group performed the exercise program for 8 weeks; however, the control group followed their routine program. The pain was assessed by the Visual Analogue Scale of pain (VAS) and the lower extremity function was assessed by the Lower Extremity Functional Scale (LEFS). In the statistical procedure, the repeated-measures Analysis of Variance (ANOVA) and Bonferroni test was applied to determine the within-group and between-groups differences of the study variables, and for assessing the stability level of protocols’ effect on the experimental group and comparing the stages, respectively. The significance level was considered 0.05, test power as 95%, and effect size as 0.7; SPSS was used for all data analyses. Results: The present study data indicated that the strengthening exercise program on hip abductor muscles caused a significant decrease in pain (P=0.0001). The lower extremity function manifested a significant improvement in the experimental group after 8 weeks of strengthening exercise protocol (P=0.0001); it was durable even 3 months after the end of the exercise program. Conclusion: Hip abductor muscle strengthening, based on NSCA protocol, can be an effective approach in reducing pain and improving lower extremity function in elite distance runners with ITBS.

Introduction: Energy Consumption (EC) and Body Mass Index (BMI) are the major complications associated with Spinal Cord Injury (SCI), which can be improved by exercise rehabilitation. Thus, the present study aimed to evaluate the efficiency of using rebound therapy (exercise on a trampoline) on EC and BMI in individuals with SCI. Materials and Methods: Sixteen individuals with SCI (ASIA classification: A=6, B=6, C=2, D=2) were selected and randomly divided into two groups of experimental (rebound exercise) and control. The experimental group performed the exercise program by a modified trampoline for 12 weeks (10-30 minutes; 3 sessions a week). EC was measured by the Physiological Cost Index (PCI) and BMI was calculated by standard formula before and after the exercise intervention. Finally, the obtained data were analyzed by Repeated-Measures Analysis of Variance (RM-ANOVA) in SPSS. Results: The results of RM-ANOVA revealed significant interaction in both criteria (P<0.01). In other words, the experimental group changes were substantial, compared to that of the control group. Conclusion: The collected results indicated that rebound therapy could, in effect, improve the SCI individuals’ EC and BMI. Furthermore, it was suggested that rebound exercise can be a useful sports rehabilitation method for patients with SCI.

Introduction: Autism Spectrum Disorder (ASD) is among the most common childhood disorders. The current study aimed to investigate the effect of Kangoo Jump (KJ) exercises on dynamic balance and overall postural oscillations in children with ASD. Materials and Methods: This was a quasi-experimental study. Among children with ASD in the Autism Association and Autism Schools in Tehran City, Iran, 20 subjects were selected using screening tests; after assessing the dynamic balance and general postural sway as a pretest, they were randomly divided into two groups of experimental and control. The experimental group performed KJ exercises for 8 weeks; eventually, all individuals were tested for dynamic balance and postural control as a posttest. The obtained data were analyzed using Analysis of Covariance (ANCOVA). Results: This study suggested that performing KJ significantly improved the dynamic balance in children with an ASD disorder. There was a significant difference between the mean scores of the control and experimental groups in the posttest stage in dynamic equilibrium (P<0.001); however, no difference was observed between the study groups in postural control. Conclusion: Using KJ to improve dynamic balance in children with ASD is beneficial. Therefore, these interventions can improve various aspects of development and balance in children with ASDs.

Introduction: The present study aimed to investigate the effects of 6 weeks of Dynamic Neuromuscular Stability (DNS) training on performance (lower limb strength, flexibility, fall risk) and quality of life in the elderly. Materials and Methods: This was a quasi-experimental study with a pretest-posttest design. This research was performed on 30 elderly males, aged 60-70 years in Qom Province, Iran in 2021. The examined elderly were randomly divided into the experimental and control groups (n=15/group). Furthermore, the experimental group participated in three 45-minute weekly sessions of DNS training for 6 weeks. To collect the necessary information before and after applying the training protocol, tint tests, 30-second seat sitting test, sitting and delivery test, TUG test, and SF-36 questionnaire were used. The obtained data were analyzed using Analysis of Covariance (ANCOVA) and Paired Samples t-test at a significance level of 0.05. Results: The ANCOVA results indicated a significant difference between the experimental and control groups in motor function, fall risk, quality of life, lower limb strength, and flexibility (P<0.05). The collected mean scores outlined that the experimental group performed better than the control group. Conclusion: Due to the effectiveness of DNS training on physical function and the very high importance of the elderly lifestyle, it is recommended that the provided training protocol be used for prevention and rehabilitation, increase the level of physical fitness and quality of life as a low-cost treatment, among the elderly.

Introduction: The current study aimed to evaluate the effects of different musical intensities on performance and cardiovascular responses after incremental exercise in male athletes.  Materials and Methods: In this quasi-experimental study with a cross-over design, 15 male athletes were voluntarily selected. The study subjects performed Bruce protocol, along with listening to progressive music, slow music, and without music until exhaustion.  Results: This study indicated that systolic and diastolic blood pressure, maximum oxygen consumption, maximum heart rate, and time to exhaustion insignificantly decreased while listening to slow music, compared to the no music (P=0.134, P=0.993, P=0.999, P=0.160, P=0.819, respectively). Furthermore, while listening to progressive music, compared to no music, the systolic and diastolic blood pressure, as well as maximum heart rate insignificantly increased (P=0.735, P=0.999, P=0.496, respectively); the maximum oxygen consumption and the time of exhaustion significantly increased in the study subjects (P=0.043, P=0.008 respectively). Moreover, while listening to progressive music, compared to slow music, the systolic blood pressure, maximum oxygen consumption, maximum heart rate, and the time of exhaustion significantly increased (P=0.004, P=0.009, P=0.002, P=0.001 respectively); however, diastolic blood pressure presented an insignificant decrease (P=0.253).  Conclusion: The obtained findings revealed that listening to progressive music can affect physiological factors and performance during exercising. It increases the athlete’s motivation and postpones the time to exhaustion to continue exercising; however, listening to slow music creates a state of relaxation during exercise and reduces heart rate. As a result, individuals with hypertension can decline their blood pressure during endurance exercise by listening to soft music.

Introduction: This research aimed to compare the effects of the Williams and core stability training on dynamic balance and back pain in women with chronic back pain.  Materials and Methods: In total, 45 women with chronic back pain were selected as the available sample and were randomly divided into 3 groups of 15 participants, including core stability, Williams, and control. Before the beginning and the end of the training period, the dynamic balance with the Star Excursion Balance Test (SEBT) and low back pain with Québec Questionnaire was measured. To analyze the obtained data, Analysis of Covariance (ANCOVA) was used in SPSS at P<0.05. Results: The present study findings revealed a significant difference in core stability and Williams training on dynamic balance and improvement in the extent of low back pain in the study participants. There was a significant difference between the training groups in dynamic balance; however, there was no significant difference in the improvement of low back pain between the experimental groups. Conclusion: To improve dynamic balance, a core stability training program is recommended, and Williams’ flexor movements are more appropriate for reducing low back pain.

Introduction: The present study aimed to examine a proposed model for the relationship between resilience and emotional reactions to failure, mediated by self-compassion and Emotion Regulation (ER) among martial artists. Materials and Methods: A total of 286 athletes (191 males & 95 females; Mean±SD age: 20.98±3.30 years) from different disciplines of martial arts (taekwondo, karate, Judo, & wushu) engaged in league championship participated in the study. Athletes completed the Sports Mental Toughness Questionnaire (SMTQ), the Positive and Negative Affect Schedule (PANAS), the Self-Compassion Scale (SCS), and the Cognitive Emotion Regulation Questionnaire (CERQ). The proposed model was evaluated using structural equation modeling. Results: The obtained results revealed that resilience has direct and indirect effects on emotional reactions to failure. Furthermore, self-compassion and maladaptive ER play a partial negative mediating role between resilience and emotional reactions to failure. However, the mediating role of adaptive ER was not significant. Conclusion: The study data predicted negative emotional reactions to failure based on resilience, mediated by self-compassion and ER among martial artists; thus, these data indicate the necessity of paying attention to the development of resilience in martial artists. This method emphasizes self-compassion and the reduction of maladaptive ER for better recovery of failure and reduces its effects.