scholarly journals Strength of the Shoulder Rotators in Second-League Volleyball Players

2015 ◽  
Vol 22 (4) ◽  
pp. 215-218
Author(s):  
Aneta Popieluch ◽  
Michał Staniszewski ◽  
Michał Wychowański
Keyword(s):  
Maximal Voluntary Contraction ◽  
Peak Torque ◽  
Voluntary Contraction ◽  
Statistical Testing ◽  
Control Group ◽  
Horizontal Position ◽  
Left Limb ◽  
Volleyball Players ◽  
Torque Values ◽  
The Right

AbstractIntroduction.The main aim of the study was to assess the strength of the shoulder rotator muscles of a group of second-league volleyball players. These muscles are assumed to have a crucial impact on attack effectiveness in volleyball. Strength was assessed based on peak torque values obtained for the rotator muscles measured using the maximal voluntary contraction (MVC) method. Torque was measured in both limbs and the differences between the two limbs were examined. The torque values obtained for the volleyball players were also compared against those measured in a group of students who had never trained any sports.Material and methods.The study involved 20 students (mean age = 20 ± 1 years) who played in the second league when the study was conducted. Their results were compared with those of a control group consisting of 30 students (mean age = 20 ± 1 years) who had not trained any sports. Peak torque of the shoulder rotator muscles was measured during external and internal rotation of the shoulder in isometric conditions. The assessment was performed on a special measuring station with the forearm in a vertical and horizontal position. The following basic statistics were calculated for the torque values obtained in the measurement: the mean, standard deviation, minimum value, and maximum value. The data were then subjected to statistical testing.Results.Compared to the students, the volleyball players had higher torque values of the internal and external rotators of the right and left shoulders, in both positions of the forearm. When the results obtained for the right and left limbs were compared for the group of volleyball players, it was found that the torque values for the right limb, which was the dominant limb, were significantly higher than those recorded for the left limb. The study also showed that the position of the forearm had an impact on torque values: when the forearm was in a horizontal position, higher mean values were obtained for the external rotators of the right (p < 0.05) and left (p < 0.01) limbs, and when it was in a vertical one, the internal rotators were stronger compared to the external rotators.Conclusions.The shoulder rotator muscles of the volleyball players were found to be considerably stronger than those of the students, and the rotators of the dominant limb were significantly stronger than those of the non-dominant limb in the group of volleyball players. The position of the forearm had a considerable impact on the strength of the internal and external rotator muscles. The maximal voluntary contraction method used in the study can be helpful in measuring the strength of the shoulder rotator muscles in any phase of the training process.

scholarly journals Biomechanical Assessment of the Strength of Volleyball Players in Different Stages of the Training Macrocycle

2015 ◽  
Vol 22 (3) ◽  
pp. 148-152
Author(s):  
Marcin Śliwa ◽  
Tomasz Sacewicz
Keyword(s):  
Lower Limbs ◽  
Training Methods ◽  
Lower Velocity ◽  
Locomotor System ◽  
Strength Capacity ◽  
Extensor Muscles ◽  
Left Limb ◽  
Volleyball Players ◽  
Torque Values ◽  
The Right

Abstract Introduction. In order to help volleyball players achieve superior results, their coaches are constantly seeking new training methods. One of the methods used to improve the effectiveness of the training that is being implemented is conducting tests which make it possible to assess the player’s locomotor system in terms of its motor and biomechanical functions. The aim of the study was to determine the torque of the knee flexor and extensor muscles of volleyball players in three stages of the annual macrocycle. Material and methods. The study involved 14 volleyball players. Torque was assessed using the BIODEX System 4 Pro at the angular velocities of 60°/s and 180°/s, in three periods of the annual training macrocycle. Results. After the preparatory training period, there was a statistically significant increase in the torque of the flexor and extensor muscles of the lower limbs, both for the lower velocity (p ≤ 0.02 for the right limb and p ≤ 0.024 for the left limb) and the higher one (p ≤ 0.03 for the right limb and p ≤ 0.034 for the left limb). After the preliminary round, statistically insignificant changes were found for the torque values obtained at both velocities. Conclusions. The study showed that frequent monitoring of players can help assess their strength capacity in a more reliable way. The results of such measurements carried out in different periods of the volleyball season can help evaluate the players’ strength at a given moment, verify and modify the training methods which are being used, and approach each player individually.

scholarly journals Changes in the Stiffness of Thigh Muscles in the Left and Right Limbs During Six Weeks of Plyometric Training in Volleyball Players

2018 ◽  
Vol 25 (2) ◽  
pp. 20-24 ◽  
Author(s):  
Dariusz Mroczek ◽  
Edward Superlak ◽  
Marek Konefał ◽  
Krzysztof Maćkała ◽  
Paweł Chmura ◽  
...  
Keyword(s):  
Good Method ◽  
Optimal Level ◽  
Muscle Stiffness ◽  
Plyometric Training ◽  
Thigh Muscles ◽  
Left Limb ◽  
Significant Difference ◽  
Volleyball Players ◽  
Left And Right ◽  
The Right

Abstract Introduction. Monitoring muscle stiffness in athletes can be a good method of assessing fatigue caused by high training loads, and the early detection of fatigue can help prevent the occurrence of micro-trauma in the muscles that can cause contusions. The research carried out by Wilson et al. [1] confirmed that an optimal level of muscle stiffness is significantly correlated with high muscle loads. The aim of the current study was to determine changes in muscle stiffness of the left and right thighs during six weeks of plyometric training (PT) in volleyball players. Material and methods. The study involved 16 volleyball players from the second-league Opole University of Technology Club (age = 21.12 ± 1.66 years, height = 191.62 ± 5.73 cm, and weight = 86.25 ± 6.66 kg) with at least five years of competitive experience (7.5 ± 2.44 years). Muscle stiffness was measured during three stages of the plyometric training using a MYOTON PRO device (Estonia). Results. An RM-ANOVA analysis showed a significant difference in the resting stiffness of the semitendinosus (posterior thigh) muscles of the left and right limbs before the plyometric training began, but no significant differences were found in the stiffness of these muscles in the fourth or sixth weeks of training. The results of the measurement performed for the anterior muscles of the thigh did not reveal a significant difference in the stiffness of the left limb compared to that of the right limb in subsequent weeks of training. Conclusion. The loads used in plyometric training in volleyball players caused a decrease in the differences in muscle stiffness between the left and right limbs, and in both limbs, adaptation trended towards an increase or a decrease in stiffness.

scholarly journals The Effects of Ankle Sprain on Balance Tests in Adolescent Volleyball Players with Previous History of Ankle Sprain

2014 ◽  
Vol 2 (11_suppl3) ◽  
pp. 2325967114S0018
Author(s):  
Ceyda Sarıal ◽  
Abdulhamıt Tayfur ◽  
Beyza Kap ◽  
Dılara Donder ◽  
Ozum Melıs Ertuzun ◽  
...  
Keyword(s):  
Ankle Sprain ◽  
Previous History ◽  
Control Group ◽  
Balance Test ◽  
Balance Tests ◽  
Volleyball Players ◽  
History Of ◽  
One Year ◽  
The Right ◽  
The Impact

Objectives: To investigate the impact of having previous history of inversion ankle sprain on balance tests in adolescent volleyball players. Methods: Fourty-five adolescent volleyball players with mean age of 15.26±1.03 participated in our study. Twenty-nine were uninjured (control group) and sixteen had previously experienced inversion injuries on right ankle. 9 players had the injury more than than one year ago and 7 players had it before six to twelf months. Balancing abilities were evaluated by Star Excursion Balance Test (SEBT) and Single Limb Hurdle Test (SLHT). The fact that players with history of injury had the ankle sprain at right foot led us to perform the measurements in the control group also for the right foot. We compared the results of injured and uninjured players on both tests. Results: Uninjured players' reaching distance on right foot was found out to be significantly more than in players with ankle sprain at medial and posteromedial directions of SEBT(p<.05), whereas there were no differences detected for the other directions (p>.05). For comparing athletes' performances with SLHT, finishing time was found significantly better in uninjured players (p<.05). Conclusion: Adolescent volleyball players with history of injury show lower performance on balance tests compared to uninjured players. This demonstrates that they should be given a training including balance and stabilization programs.

scholarly journals Profile of aerobic fitness and muscle power of athletes on the Brazilian National Paralympic Five-a-side Football Team

2019 ◽  
Vol 33 (3) ◽  
pp. 345-352
Author(s):  
Eduardo Da Silva Alves ◽  
Valdir De Aquino Lemos ◽  
João Paulo Pereira Rosa ◽  
Andressa Da Silva ◽  
Junior Gavea ◽  
...  
Keyword(s):  
Aerobic Fitness ◽  
Muscle Power ◽  
Ventilatory Threshold ◽  
Peak Torque ◽  
Peak Oxygen Uptake ◽  
Maximum Speed ◽  
Football Team ◽  
Torque Values ◽  
The Right ◽  
Physical Capacities

We aimed to profile the aerobic fitness and muscle power of five-a-side football athletes on the Brazilian National Paralympic Team. The sample consisted of 12 male Paralympic athletes on the Brazilian National five-a-side football team, including 3 sighted goalkeepers and 9 blind (B1 category) outfield players. The results were: peak oxygen uptake (VO2 peak), 51.8 ± 5.8 ml/kg/min; maximum speed, 17.1 ± 1.4 km/h and VO2 ventilatory threshold (VT), 40.2 ± 6.5 ml/kg/min The peak torque values (Nm) of the right and left legs were 241 ± 48 and 234 ± 45 for 60° extension, 127 ± 17 and 123 ± 16 for 60° flexion, 170 ± 29 and 162 ± 28 for 180° extension, 113 ± 13 and 109 ± 13 for 180° flexion, 130 ± 20 and 129 ± 23 for 300° extension, and 118 ± 17 and 115 ± 18 for 300° flexion, respectively. The five-a-side football players on the Brazilian National Paralympics Team exhibited physiologically normal responses to physical training related to the observed physical capacities as shown by the aerobic fitness and muscle power results observed. These results suggest that blind individuals can improve their physical capacity regardless of their visual impairment.

Neuromuscular adaptations to training

1987 ◽  
Vol 63 (6) ◽  
pp. 2396-2402 ◽  
Author(s):  
R. J. Cannon ◽  
E. Cafarelli
Keyword(s):  
Internal Control ◽  
Voluntary Contraction ◽  
Control Group ◽  
Adductor Pollicis Muscle ◽  
Reduction In Force ◽  
Neuromuscular Adaptations ◽  
The Right ◽  
Central Adaptation ◽  
Contralateral Muscle ◽  
Adaptation To Training

The purpose of this experiment was to determine whether there is a central adaptation to resistance overload. The right adductor pollicis muscle of each subject was trained with either voluntary (n = 9) or electrically stimulated contractions (n = 7), the contralateral muscle acted as an internal control, and seven other subjects acted as a control group. Training was the same in both groups: 15 contractions at 80% maximal voluntary contraction (MVC), 3 days/wk for 5 wk. Trained muscles in both groups increased MVC by approximately 15% (voluntary, P less than 0.01; stimulated, P less than 0.05). There was a small (9.5%) but significant (P less than 0.05) increase in MVC of the untrained muscles in the voluntary group. MVC did not change in the control group. Maximal electromyogram (EMG) was highly reproducible pre-to posttraining in the control group (r = 0.92, slope = 0.995) and did not change pre- to posttraining in the trained groups. Sensory adaptation to training caused a reduction in force sensation in the stimulated group (P less than 0.05) but not in the voluntary group. Because there was a small increase in MVC of the untrained muscle of the voluntary group (9.5%, P less than 0.05) but not in the stimulated group, it is possible that there is a central motor adaptation, but it is not manifested in increased neural drive (EMG). Moreover, this central adaptation may be responsible for the decrease in force sensation that follows training.

scholarly journals Comparative study between fibrin glue and platelet rich plasma in dogs skin grafts

2012 ◽  
Vol 27 (11) ◽  
pp. 789-794 ◽  
Author(s):  
Larissa Correa Hermeto ◽  
Rafael de Rossi ◽  
Santiago Benites de Pádua ◽  
Elenir Rose Jardim Pontes ◽  
Aureo Evangelista Santana
Keyword(s):  
Fibrin Glue ◽  
Platelet Rich Plasma ◽  
Control Group ◽  
Skin Grafts ◽  
Full Thickness ◽  
Clinical Evaluations ◽  
Thickness Skin ◽  
Left Limb ◽  
The Right ◽  
Mesh Skin Graft

PURPOSE: Compare fibrin glue (Tissucol®) and platelet-rich plasma in full-thickness mesh skin grafts in dogs. METHODS: Eighteen dogs were used, divided into two groups: fibrin glue (FG) and platelet-rich plasma (PRP). In all the animals, a full-thickness 3x3 cm mesh skin graft was implanted. In the left limb, the biomaterial was place between the graft and the receptor bed, according to the group, while the right limb served as the control group. All the animals were evaluated clinically every 48 hours until the 14th day, using the variables of exudation, coloration, edema and cosmetic appearance. Three animals were evaluated histologically, on the third, seventh and tenth postoperative days, using the variables of fibroblasts, collagen, granulation tissue, microscopic integration-adherence and acute inflammation. RESULTS: Clinical evaluations showed that the group CF showed better scores for all variables compared to PRP group. On the histological evaluations PRP group had a higher presence of fibroblasts in the seventh and fourteenth days. CONCLUSION: The fibrin glue group was clinically superior to the platelet-rich group when used on full-thickness skin grafts in dogs.

Factors Affecting Force Loss With Prolonged Stretching

2001 ◽  
Vol 26 (3) ◽  
pp. 262-272 ◽  
Author(s):  
David G. Behm ◽  
Duane C. Button ◽  
Jeremy C. Butt
Keyword(s):  
Maximal Voluntary Contraction ◽  
Muscle Activation ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Control Group ◽  
Tetanic Force ◽  
Factors Affecting ◽  
Passive Stretching ◽  
Interpolated Twitch Technique ◽  
Muscle Compliance

The purpose of this study was to investigate factors underlying the force loss occurring after prolonged, static, passive stretching. Subjects were tested before and 5-10 min following 20 min of static, passive stretching of the quadriceps (N = 12) or a similar period of no stretch (control, N = 6). Measurements included isometric maximal voluntary contraction (MVC) force, surface integrated electromyographic (iEMG) activity of the quadriceps and hamstrings, evoked contractile properties (twitch and tetanic force), and quadriceps inactivation as measured by the interpolated twitch technique (ITT). Following stretching, there was a significant 12% decrement in MVC with no significant changes in the control group. Muscle inactivation as measured by the ITT and iEMG increased by 2.8% and 20.2%, respectively. While twitch forces significantly decreased 11.7%, there was no change in tetanic force post-stretch. Although possible increases in muscle compliance affected twitch force, a lack of tetanic force change would suggest that post-stretch force decrements are more affected by muscle inactivation than changes in muscle elasticity. Key Words: antagonist, electromyography, maximum voluntary contraction, muscle activation, twitch, tetanus

scholarly journals Eccentric Hip Muscle Function in Females With and Without Patellofemoral Pain Syndrome

2009 ◽  
Vol 44 (5) ◽  
pp. 490-496 ◽  
Author(s):  
Rodrigo de Marche Baldon ◽  
Theresa Helissa Nakagawa ◽  
Thiago Batista Muniz ◽  
César Ferreira Amorim ◽  
Carlos Dias Maciel ◽  
...  
Keyword(s):  
Muscle Function ◽  
External Rotation ◽  
Pain Syndrome ◽  
Peak Torque ◽  
Patellofemoral Pain Syndrome ◽  
Patellofemoral Pain ◽  
Control Group ◽  
Hip Muscle ◽  
Hip Abduction ◽  
Torque Values

Abstract Context: Patellofemoral pain syndrome (PFPS) is a common knee condition in athletes. Recently, researchers have indicated that factors proximal to the knee, including hip muscle weakness and motor control impairment, contribute to the development of PFPS. However, no investigators have evaluated eccentric hip muscle function in people with PFPS. Objective: To compare the eccentric hip muscle function between females with PFPS and a female control group. Design: Cross-sectional study. Setting: Musculoskeletal laboratory. Patients or Other Participants: Two groups of females were studied: a group with PFPS (n  =  10) and a group with no history of lower extremity injury or surgery (n  =  10). Intervention(s): Eccentric torque of the hip musculature was evaluated on an isokinetic dynamometer. Main Outcome Measure(s): Eccentric hip abduction, adduction, and external and internal rotation peak torque were measured and expressed as a percentage of body mass (Nm/kg × 100). We also evaluated eccentric hip adduction to abduction and internal to external rotation torque ratios. The peak torque value of 5 maximal eccentric contractions was used for calculation. Two-tailed, independent-samples t tests were used to compare torque results between groups. Results: Participants with PFPS exhibited much lower eccentric hip abduction (t18  =  −2.917, P  =  .008) and adduction (t18  =  −2.764, P  =  .009) peak torque values than did their healthy counterparts. No differences in eccentric hip external (t18  =  0.45, P  =  .96) or internal (t18  =  −0.742, P  =  .47) rotation peak torque values were detected between the groups. The eccentric hip adduction to abduction torque ratio was much higher in the PFPS group than in the control group (t18  =  2.113, P  =  .04), but we found no difference in the eccentric hip internal to external rotation torque ratios between the 2 groups (t18  =  −0.932, P  =  .36). Conclusions: Participants with PFPS demonstrated lower eccentric hip abduction and adduction peak torque and higher eccentric adduction to abduction torque ratios when compared with control participants. Thus, clinicians should consider eccentric hip abduction strengthening exercises when developing rehabilitation programs for females with PFPS.

A model for quantitative strength training of hindlimb muscles of the rat

1988 ◽  
Vol 64 (4) ◽  
pp. 1740-1745 ◽  
Author(s):  
H. Klitgaard
Keyword(s):  
Strength Training ◽  
Skeletal Muscles ◽  
Training Period ◽  
Control Group ◽  
Trained Group ◽  
Plantar Flexors ◽  
Hindlimb Muscles ◽  
Left Limb ◽  
The Right

Rats were taught to lift up a lever to train the plantar flexors. After 2 wk of adaptation the rats were trained for 36 wk. The mass of weights on the lever rose by 85% over the 36-wk period (P less than 0.05) The estimated force that the plantar flexors had to develop to lift the lever rose by 32% (P less than 0.05), just as the work per lift rose by 28% (P less than 0.05). For the trained group of rats the soleus muscles of the right and the left limb were 34% (P less than 0.05) and 31% (P less than 0.05) heavier, respectively, after the training period than those of the control group. Similarly, the plantaris muscles of both the right and the left limb were 24% heavier (P less than 0.05). For the trained group the maximum twitch and tetanus tensions of the soleus were 63% (P less than 0.05) and 65% (P less than 0.05) higher, respectively. Relative to the plantaris these measures were 79% (P less than 0.05) and 37% (P less than 0.05), respectively. The described model, therefore, seems appropriate for the study of the skeletal muscles' adaptation to usage.

scholarly journals Potentiation and Electrical Stimulus Frequency During Self-Paced Exercise and Recovery

2014 ◽  
Vol 42 (1) ◽  
pp. 91-101 ◽  
Author(s):  
Christian Froyd ◽  
Fernando G. Beltrami ◽  
Jørgen Jensen ◽  
Guillaume Y. Millet ◽  
Timothy David Noakes
Keyword(s):  
Stimulus Frequency ◽  
Time Trial ◽  
Peak Torque ◽  
Electrical Stimulus ◽  
Voluntary Contraction ◽  
Peripheral Fatigue ◽  
Paired Stimuli ◽  
Torque Measurements ◽  
Before And After ◽  
The Right

Abstract The aim of this study was to investigate the effect of potentiation on stimulation-induced muscle function during and after an intense bout of self-paced dynamic exercise. Ten active subjects performed a time trial involving repetitive concentric extension-flexion of the right knee using a Biodex dynamometer. Electrical stimulation before and after a 5 s maximal isometric voluntary contraction was performed before the start of the time trial and immediately (< 5 s) after each 20% of the time trial as well as 1, 2, 4 and 8 min after time trial termination. Potentiation was observed before the time trial and as early as 1-2 min after the time trial, but no potentiation was detected during or immediately after the time trial for neither single or paired stimuli. At termination of the time trial, “potentiated” peak torque was significantly more reduced than “unpotentiated" peak torque for single stimulus (-65 ± 10% and -42 ± 18%, respectively) and paired stimuli at 100 Hz (-51 ± 10% and -33 ± 15%, respectively). Faster recovery for “potentiated” compared to “unpotentiated” peak torque indicate that potentiate peak torque measurements or delay the post-exercise measurements more than a few seconds, will underestimate peripheral fatigue. In conclusion, the potentiation after maximal contraction disappears during intense exercise. Whether the muscle is already potentiated during intense contraction or fatiguing mechanisms inhibits potentiation remains to be clarified

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