Research in Sport Medicine and Technology

---

Transcranial direct current stimulation (tDCS) is one of the newest supplementary method in order to improve the athletic performance and mental preparation of professional athletes. In this study, we investigated the effects of 10-session unihemispheric concurrent dual-site anodal-tDCS (a-tDCS) of the primary motor cortex (M1) and dorsolateral prefrontal cortex (DLPFC), on swimming performance, mental toughness (MT) and perceived exertion. 20 male professional swimmers (Age: 19.00±2.86 yrs) were participated in this randomized, double-blind, and sham-controlled study. 100m free-style swimming test, the sport mental toughness questionnaire (SMTQ) and rating of perceived exertion (RPE) were evaluated as pre-tests. Then, athletes received 10-session tDCS (2mA for 20 min). 48 hrs following 10^th session of tDCS, evaluations were repeated. ANCOVA was used for statistical analysis. After multi sessions of tDCS, swimming performance improved significantly (P=0.03) and total MT score increased significantly (P=0.046) and no significant change was observed in RPE. Based on the results of this study, multi-session tDCS along with routine training are recommended to improve swimmers performance and psychological aspects. Therefore, tDCS might be consider as a brain conditioning method.
 

---

Introduction and aim: Fatigue of injury-prone athletes and their placement in situations such as performing shear maneuvers increases the risk of anterior cruciate ligament injury. Therefore, this research aims to answer the question, does functional fatigue change the effect of neuromuscular training on kinetic variables during cutting in injury-prone male athletes?
Methodology: The current research is semi-experimental and was carried out in two control and experimental groups as a pre-test and post-test design with and without fatigue before and after neuromuscular exercises. 32 males student-athletes aged 18 to 25 with trunk control defects were purposefully selected and randomly placed in the control group (16 people) and the experimental group (16 people). The force plane was used to measure ground reaction forces. Analysis of variance test was used for statistical analysis at a level smaller than P<0.05.
Results: The results of the present study showed a significant improvement in ground reaction force variables in the post-test of the experimental group compared to the pre-test (P<0.05). While none of these variables had significant changes in the control group (P>0.05).
Conclusion: It seems that doing trunk and hip neuromuscular training in athletes with a trunk control defect leads to a significant improvement in the stability of the trunk control, so in the conditions with and without fatigue, they were able to show a significant improvement in the selected parameters of the ground reaction forces. Therefore, this training method can probably be recommended as a beneficial method for athletes and the mentioned conditions

---

Background: In sports such as handball, tennis and volleyball the player need to involve the great loads over his shoulders. In these sports, players are predisposed to overuse injuries. Infraspinatus syndrome’s meaning is the painless weakness and atrophy of this muscle that observe following Suprascapularis nerve neuropathy. In this investigation we want to survey the effects of a short term of progressive endurance-strengthening training and electrical stimulation on strength and electromyography in infraspinatus muscle. Method: 12 volleyball players with Infraspinatus syndrome were randomly divided to two groups: progressive endurance-strengthening training (6 persons, age 24/8±3/8, height 189/3±2/6, weight 83/8±7/9, sport background 9/4±2/5 and national team’s background 3/24±1/7) and electrical stimulation (6 persons, age 24/2±4/5, height 192/5±1/5, weight 86/2±6/4, sport background 8/5±4 and national team’s background 4/3±2/8). 20 persons of healthy players were considered to be as a control group (age 25/1±4/2, height 187/7±3/9, weight 75/6±7/1, sport history 9±3/8 and national team history 3/9±2/3), too. Therapeutic interventions performed for 8 weeks. Surface electromyography of infraspinatus and tress minor muscles and maximal isometric strength of external rotator muscles were measured before and after interventions. Data analyzing performed by SPSS.12 and we used of Paired sample T test and one-way ANOVA. Confidence level considered to be 95% (P<0.05). Results: After eight weeks, maximal isometric strength of external rotators in both experimental groups was increased significantly, but there were observed no significant changes in IEMG and RMSEMG. Conclusion: Progressive endurance-strengthening training and electrical stimulation can result in increase of maximal isometric strength of shoulder external rotator muscles. But both therapeutic methods have no effect onelectromyograghic parameters in infraspinatus and tress minor muscles. It seems that we can't use of surface electromyography for detecting the effect of these protocols on above muscles (P<0/05).

---

After an ankle injury, residual symptoms can followed to recurrent sprain in
physical activity and 30% of its lead to functional ankle instability (FAI)
Therefore, the aim of this study was to examine the isokinetic concentric and
eccentric torque measures of the ankle musculature to body weight in female
athletes with and without FAI.30 female athletes, who play in pro league of
Tehran, participated in this descriptive study. Participants were assessed using
questionnaire and clinical tests. Isokinetic measurement speed for inversion and
eversion was 60 and plantar flexion and dorsi flexion was 120 degree/
second.Data were analyzed by independent T- test.The results indicated a
significant difference in peak torque of concentric plantar flexor to body weight
in FAI and healthy groups (P<0.05).Therefore, concentric plantar flexion may be
an important contributing factor to FAI; this finding could also lead to more
effective protocols in the treatment and rehabilitation of FAI

---

The aim of the present study was to investigate the effect of glucose and glutamine supplementation on serum HSP72, in non-athlete men during four weeks exhaustive endurance - intermittent training that causes glycogen depletion. For this purpose 20 non-athlete healthy men were selected and randomly divided into four groups including: glucose supplementation with glycogen depletion training group (n = 5, supplement 1), glutamine supplementation with glycogen depletion training group (n = 5, supplement 2), glycogen depletion training group (n = 5, placebo) and a group without any treatment (n = 5, control). The blood samples were collected at the onset of training protocol period and 48 hours after final training session from anticubital venous. Serum HSP72 concentration were determined by ELISA technique. The main and interaction effects of variables were determined using TWO WAY ANOVA compeleted with Tukey post-hoc test. The significant level was chosen as &alpha; = 0.05.The results showed the significant effect of training variable for serum HSP72 concentration, [F(1,17)= 6.362 P<0.05] . The effect of supplementation variable was significant for serum HSP72 concentration, [F(1,17)= 15.362 P<0.01] . Post-hoc test showed the significant difference between placebo with supplement 1 group (p<0.05) and placebo with supplement 2 group (p<0.01). The interaction effect between two variables was not significant. In summery, the results suggested that in glycogen depletion training condition, glucose or glutamine supplementation have significant effect on serum HSP72 concentration.

---

Aims: This study investigated the effects of creatine and L-carnitine supplementation on anaerobic
performance and body weight changes in athletes. Methods: In this single-blind randomized clinical trial, 45
athletes were selected and randomly divided into four groups supplemented with: a) Creatine, b) L-carnitine,
c) Creatine- L- carnitine and D) placebo. The supplementation period was 28 days. Wingate anaerobic test
was done for assessing athletes' anaerobic performance and their weights were measured before and after
the supplementation period. To compare the variables before and after each test, paired t-test and anova
are used compare within and between variables respecdivey. Results: The anaerobic performance indices
in the groups receiving creatine and creatine- L-carnitine were significantly increased after intervention. Body
weights were also significantly increased in the supplemented groups. Conclusions: Based on the dosage
and duration of supplementation in this study, concurrent creatine and L-carnitine supplementation has
positive effects on anaerobic performance. Despite L-carnitine is a weight loss agent, the findings of this
study showed weight gain in the supplemented groups.

---

Considering the important role of the scapula in the glenohumeral joint movements, its position on the thorax can affect the function of the joint. Therefore, the purpose of this study was to investigate the predictive relationship of the strength and glenohumeral rotation range of motion (ROM) with scapular dyskinesis (SD) in female athletes with overhead-throwing pattern. The present study was a descriptive-correlational research on 60 athletic female in volleyball, handball, basketball and badminton. The Lateral scapular slide test was used to examine SD. the dynamometer and goniometer were used to measure the strength and glenohumeral rotation ROM respectively. Data were analyzed using Spearman correlation and multiple regression tests. The correlation coefficients between SD and the glenohumeral internal rotation ROM (r=-0.734; p=0.000), the glenohumeral external rotation ROM (r=0.693; p=0.001), the glenohumeral internal rotation strength (r=0.674; p=0.005) and the glenohumeral external rotation strength (r=-0.719; p=0.001) were significant. Analysis of the research model showed that about one-third (30.1%) of total changes in SD were dependent on the independent variables mentioned in this regression model. therefore, screening of  athletes with overhead-throwing pattern must be taken into consideration in order to recognize SD, and participate in corrective exercises to increase the glenohumeral internal rotation ROM and the glenohumeral external rotator muscles strength.
 

---

 

---

---