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1.
Abstract

The aim of this study was to examine the deltoid muscle properties of the dominant and non-dominant arm of Greek professional male tennis players. Eight male tennis players (mean age 22.0 years, s = 3.2) were subjected to biopsy of the deltoid muscle of both arms. Adenosine triphosphate (ATPase) histochemistry and myosin heavy chain (MHC) composition were performed on the samples with homogenate electrophoresis. No significant differences were observed in the percentage of types I, IIa, IIab, and IIb muscle fibres between the deltoid muscles of the two arms. Types I, IIa, and IIx muscle fibres of the dominant and non-dominant deltoid muscles did not differ significantly for MHC isoform composition. Type IIab muscle fibres showed a similar cross-sectional area (CSA) percentage distribution between the two arms. The CSA percentage for types I, IIa, and IIb muscle fibers did not differ significantly between the dominant and the non-dominant arm. We conclude therefore that regular tennis training probably does not lead to any significant changes in the muscle fibre types of the dominant and non-dominant arms of elite tennis players.  相似文献   

2.
ABSTRACT

The purpose of the present study was to compare the myosin heavy chain (MHC) isoform composition of the deltoid and vastus lateralis muscles of the dominant and non-dominant limbs in handball players. Eleven male Greek elite handball players (age 22.6 ± 1.9 yrs, training experience 10.6 ± 2.1 yrs, height 184.1 ± 4.1 cm, and weight 81.0 ± 12.5 kg) participated in the study. Four muscle biopsies were obtained from the dominant and non-dominant deltoid and vastus lateralis muscles during the in-season period. The MHC composition was determined using SDS-PAGE. No significant difference was found between the dominant and non-dominant muscles; Deltoid muscle: MHC I [(95%CI = ?1.22, 0.33), P = 0.228], MHC ΙΙa [(95%CI = ?0.32, 1.59), P = 0.168] and MHC IIx [(95%CI = ?1.49, 1.10), P = 0.749]; Vastus lateralis muscle: MHC I [(95%CI = ?0.38, 0.63), P = 0.586], MHC ΙΙa [(95%CI = ?0.50, 0.65), P = 0.783] and MHC IIx [(95%CI = ?1.08, 0.42), P = 0.355]. The findings of the present study indicate that the greater use of the dominant limbs for throwing actions and body movements in handball do not lead to altered MHC isoform composition compared to the non-dominant limbs.  相似文献   

3.
The aim of the present study was to examine the relationships between muscle cross-sectional area (CSA) and muscular strength in terms of knee extension and flexion, hip extension and flexion, and hip abduction and adduction among well-trained soccer players. Fourteen university soccer players participated in the study, who had previously been divided into two groups based on ability (Group A: above-average ability; Group B: average ability). Maximal isokinetic and concentric muscular strength was measured in knee extension/flexion, hip extension/flexion and hip abduction/adduction using an isokinetic dynamometer at 1.57 and 4.19 rad x s(-1) (3.14 rad x s(-1)) in both the dominant and non-dominant leg. The CSAs of the thigh, gluteus muscles and iliopsoas muscles were calculated based on magnetic resonance imaging. There was no significant difference between the two groups in muscle CSA and isokinetic strength. Although there were some statistically significant differences between the dominant and non-dominant leg in terms of CSA and strength (P < 0.05-0.01), these were small and negligible. Apart from a non-significant relationship between the CSAs of the adductor muscles and hip adductor strength (r < 0.26, N.S.), the CSA of the other muscle groups correlated with maximal isokinetic strength (r = 0.38-0.64, P < 0.05). These results suggest that no difference in muscle characteristics (in terms of muscle CSA and strength) was apparent among well-trained soccer players, even between the dominant and non-dominant leg. There is also a case that the anatomical function of a single (or group of) muscle(s) may not be reflected by the strength-CSA relationship depending on the movements (such as hip adduction-adductor muscle CSA). Thus, further studies are required to develop methods to assess neuromuscular function in relation to muscle morphology among soccer players.  相似文献   

4.
Abstract

The aim of the present study was to examine the relationships between muscle cross-sectional area (CSA) and muscular strength in terms of knee extension and flexion, hip extension and flexion, and hip abduction and adduction among well-trained soccer players. Fourteen university soccer players participated in the study, who had previously been divided into two groups based on ability (Group A: above-average ability; Group B: average ability). Maximal isokinetic and concentric muscular strength was measured in knee extension/flexion, hip extension/flexion and hip abduction/adduction using an isokinetic dynamometer at 1.57 and 4.19 rad·s?1 (3.14 rad·s?1) in both the dominant and non-dominant leg. The CSAs of the thigh, gluteus muscles and iliopsoas muscles were calculated based on magnetic resonance imaging. There was no significant difference between the two groups in muscle CSA and isokinetic strength. Although there were some statistically significant differences between the dominant and non-dominant leg in terms of CSA and strength (P<0.05–0.01), these were small and negligible. Apart from a non-significant relationship between the CSAs of the adductor muscles and hip adductor strength (r<0.26, n.s.), the CSA of the other muscle groups correlated with maximal isokinetic strength (r=0.38–0.64, P<0.05). These results suggest that no difference in muscle characteristics (in terms of muscle CSA and strength) was apparent among well-trained soccer players, even between the dominant and non-dominant leg. There is also a case that the anatomical function of a single (or group of) muscle(s) may not be reflected by the strength—CSA relationship depending on the movements (such as hip adduction-adductor muscle CSA). Thus, further studies are required to develop methods to assess neuromuscular function in relation to muscle morphology among soccer players.  相似文献   

5.
ABSTRACT

Table tennis requires rapid and extreme movements that may result in shoulder adaptations, such as glenohumeral internal rotation deficit, which is a risk factor for several injuries. This study compared range of motion of internal and external rotation and total rotation motion of glenohumeral joint between dominant and non-dominant shoulders of table tennis players. This is a cross-sectional observational study. Twenty healthy male table tennis players that were enrolled in an official table tennis league took part in this study (mean age: 22.9 ± 12.9 years, time of sports practice: 6.2 ± 7.12 years). Measurements of passive glenohumeral external rotation and internal rotation were taken with the individuals in the supine and sidelying positions. Total rotation motion was calculated by summing external and internal rotations. The dominant side showed decreased internal rotation when compared to non-dominant side in both supine (mean difference: 14.9°, p = 0.02) and sidelying positions (mean difference: 16.3°, p = 0.01). No significant difference (p > 0.05) was found for external rotation and total rotation motion between dominant and non-dominant shoulders. The findings indicate that table tennis players exhibit glenohumeral internal rotation deficit of dominant shoulder.  相似文献   

6.
The purpose of this study was to examine the relationship between the upper limb anthropometric dimensions and a history of dominant upper limb injury in tennis players. Dominant and non-dominant wrist, forearm, elbow and arm circumferences, along with a history of dominant upper limb injuries, were assessed in 147 male and female players, assigned to four groups based on location of injury: wrist (n = 9), elbow (n = 25), shoulder (n = 14) and healthy players (n = 99). From anthropometric dimensions, bilateral differences in circumferences and in proportions were calculated. The wrist group presented a significant bilateral difference in arm circumference, and asymmetrical bilateral proportions between wrist and forearm, as well as between elbow and arm, compared to the healthy group (6.6 ± 3.1% vs. 4.9 ± 4.0%, P < 0.01; ?3.6 ± 3.0% vs. ?0.9 ± 2.9%, P < 0.05; and ?2.2 ± 2.2% vs. 0.1 ± 3.4%, P < 0.05, respectively). The elbow group displayed asymmetrical bilateral proportions between forearm and arm compared to the healthy group (?0.4 ± 4.3% vs. 1.5 ± 4.0%, P < 0.01). The shoulder group showed significant bilateral difference in elbow circumference, and asymmetrical bilateral proportions between forearm and elbow when compared to the healthy group (5.8 ± 4.7% vs. 3.1 ± 4.8%, P < 0.05 and ?1.7 ± 4.5% vs. 1.4 ± 4.3%, P < 0.01, respectively). These findings suggest that players with a history of injury at the upper limb joint present altered dominant upper limb proportions in comparison with the non-dominant side, and such asymmetrical proportions would appear to be specific to the location of injury. Further studies are needed to confirm the link between location of tennis injury and asymmetry in upper limb proportions using high-tech measurements in symptomatic tennis players.  相似文献   

7.
The effects of exercise on the core musculature have not been investigated in prepubescents. The main purpose of the present study was to determine the volume and degree of asymmetry of rectus abdominis, obliques and transversus abdominis, quadratus lumborum, iliopsoas, gluteus and paravertebralis muscles in prepubescent tennis players and in untrained boys. The muscle volume was determined using magnetic resonance imaging (MRI) in 7 male prepubescent tennis players and 10 untrained controls (mean age 11.0 ± 0.8 years, Tanner 1–2). After accounting for height and body weight as covariates, the tennis players had 14–34% greater volume than the controls in all the muscles analysed (P < 0.05) except in paravertebralis, dominant quadratus lumborum and non-dominant gluteus, which had similar volumes in both groups (P = NS). Compared to controls, the tennis players displayed a greater degree of asymmetry in quadratus lumborum and rectus abdominis (3% vs. 15%, P < 0.01 and 8% vs. 17%, P = 0.06, respectively). The level of asymmetry of obliques and transversus abdominis, iliopsoas, gluteus and paravertebralis muscles was similar in both groups (P = NS). In conclusion, tennis playing at prepubertal ages induces a selective hypertrophy of the core musculature and exaggerates the degree of asymmetry of quadratus lumborum and rectus abdominis compared to untrained boys.  相似文献   

8.
从解剖学角度分析,人体的大块肌肉分布在躯干和下肢,小块肌肉分布在上肢。7-8岁时下肢发育领先于躯干、上肢,足长的发育领先于手长。从神经活动过程分析,儿童在神经活动方面的第一信号系统占据主导地位,其直观形象好,模仿能力强,对结构简单、常接触的动作较易掌握,同时也符合其生化特点。通过以上分析,早期发展乒乓球步法训练的最佳年龄为7-8岁。  相似文献   

9.
It is generally accepted that preadolescents have a limited capacity to develop muscle hypertrophy in response to exercise compared with older populations; however, studies are scarce and conflicting. The main aim of the present study was to assess if playing tennis is associated with the hypertrophy of dominant pectoralis muscles (PM) in professional (PRO) and in prepubescent tennis players (PRE). A secondary aim was to assess if the degree of asymmetry of PM is greater in PRO than PRE. The volume of PM of both sides was determined using magnetic resonance imaging in 8 male PRO (21.9 years), 6 male PRE (11 years, Tanner 1–2) and 12 male non-active controls (6 adults: 23.5 years; and 6 prepubescents: 10.7 years, Tanner 1–2). PRO and PRE had 15 and 30% greater volume, respectively, in the dominant than in the contralateral PM (P?P?=?.34 in adults and 5%, P?=?.17 in children). The degree of side-to-side asymmetry in PM volume was greater in PRE than in PRO (P?相似文献   

10.
This study aims to compare the isokinetic profile of hip abductor and adductor muscle groups between soccer players suffering from chronic adductor-related groin pain (ARGP), soccer players without ARGP and healthy volunteers from general population. Study included 36 male professional soccer players, who were randomly selected and followed-up over two years. Of the 21 soccer players eligible to participate in the study, 9 players went on to develop chronic ARGP and 12 players did not. Ten healthy male volunteers were randomly selected from the general population as a control group. Comparison between the abductor and adductor muscle peak torques for players with and without chronic ARGP found a statistically significant difference on the dominant and non-dominant sides (p?p?p?=?.008). The adductor muscle strength was also significantly decreased on the affected side. This imbalance appears to be a risk factor for adductor-related groin injury. Therefore, restoring the correct relationship between these two agonist and antagonist hip muscles may be an important preventative measure that should be a primary concern of training and rehabilitation programmes.  相似文献   

11.
This study investigated the effect of the larger diameter (Type 3) tennis ball on performance and muscle activation in the serve. Sixteen male advanced tennis players performed serves using regular size and Type 3 tennis balls. Ball speed, surface electromyography, and serve accuracy were measured. There were no significant differences in mean initial serve speeds between balls, but accuracy was significantly greater (19.3%) with the Type 3 ball than with the regular ball. A consistent temporal sequence of muscle activation and significant differences in mean activation of different muscles were observed. However, ball type had no effect on mean arm muscle activation. These data, combined with a previous study, suggest that play with the larger ball is not likely to increase the risk of overuse injury, but serving accuracy may increase compared to play with the regular ball.  相似文献   

12.
Tennis     
This study investigated the effect of the larger diameter (Type 3) tennis ball on performance and muscle activation in the serve. Sixteen male advanced tennis players performed serves using regular size and Type 3 tennis balls. Ball speed, surface electromyography, and serve accuracy were measured. There were no significant differences in mean initial serve speeds between balls, but accuracy was significantly greater (19.3%) with the Type 3 ball than with the regular ball. A consistent temporal sequence of muscle activation and significant differences in mean activation of different muscles were observed. However, ball type had no effect on mean arm muscle activation. These data, combined with a previous study, suggest that play with the larger ball is not likely to increase the risk of overuse injury, but serving accuracy may increase compared to play with the regular ball.  相似文献   

13.
Abstract

The study investigated different electromyographic (EMG) normalisation methods for upper-limb muscles. This assessment aimed at comparing the EMG amplitude and the reliability of EMG values obtained with each method. Eighteen male tennis players completed isometric maximal voluntary contractions and dynamic strength exercises (push-ups and chin-ups) on three separate test sessions over at least 7 days. Surface EMG activity of nine upper body muscles was recorded. For each muscle, an analysis of variance for repeated measures was used to compare maximal EMG amplitudes between test conditions. The intra-class correlation coefficient, the coefficient of variation and the standard error of measurement were calculated to determine the EMG reliability of each condition. On the basis of a compromise between maximal EMG amplitude and high reliability, the chin-ups appeared to be the optimal normalisation method for M. latissimus dorsi, M. posterior deltoid, M. biceps brachii, M. flexor carpi radialis and M. extensor carpi radialis. The push-ups seemed relevant to normalise M. anterior deltoid and M. triceps brachii activity, while isometric maximal voluntary contraction remained the most appropriate method for M. pectoralis major and M. middle deltoid. Thus, original methods are proposed to normalise EMG signal of upper-limb muscles.  相似文献   

14.
Training a non-dominant limb may increase a competitor's ability to perform with either side of his or her body and confer an advantage over competitors that use one side of the body exclusively. The aim of this study was to determine the kinematic differences between dominant and non-dominant arm throwing techniques for speed and accuracy in Under-17 and Under-19 high-performance cricketers. Seven participants performed ten throws for each arm (dominant/non-dominant) and condition (speed/accuracy) at a target positioned 10 m in front of them. Three-dimensional kinematic variables were measured using a Vicon motion analysis system. Digital footage was used to calculate stride data, ball speed, and record target accuracy. Data were analysed using repeated-measures analysis of variance and chi-squared tests. The non-dominant arm throws had significantly lower maximum lead knee lift, did not extend the lead knee in the arm acceleration phase, had significantly less elbow flexion before extension, had significantly less shoulder external rotation at the start of the arm acceleration phase, did not have a delay between the initiation of pelvic and upper torso internal rotation, and displayed a less than optimal coordination pattern. A speed–accuracy trade-off existed for the dominant arm throws. No trade-off was identified for the non-dominant arm throws. Through an enhanced understanding of how throwing technique varies between dominant and non-dominant arms, an opportunity exists for a performance-enhancing programme to be implemented so that ambidexterity of the throwing skill can be improved.  相似文献   

15.
Training a non-dominant limb may increase a competitor's ability to perform with either side of his or her body and confer an advantage over competitors that use one side of the body exclusively. The aim of this study was to determine the kinematic differences between dominant and non-dominant arm throwing techniques for speed and accuracy in Under-17 and Under-19 high-performance cricketers. Seven participants performed ten throws for each arm (dominant/non-dominant) and condition (speed/accuracy) at a target positioned 10 m in front of them. Three-dimensional kinematic variables were measured using a Vicon motion analysis system. Digital footage was used to calculate stride data, ball speed, and record target accuracy. Data were analysed using repeated-measures analysis of variance and chi-squared tests. The non-dominant arm throws had significantly lower maximum lead knee lift, did not extend the lead knee in the arm acceleration phase, had significantly less elbow flexion before extension, had significantly less shoulder external rotation at the start of the arm acceleration phase, did not have a delay between the initiation of pelvic and upper torso internal rotation, and displayed a less than optimal coordination pattern. A speed-accuracy trade-off existed for the dominant arm throws. No trade-off was identified for the non-dominant arm throws. Through an enhanced understanding of how throwing technique varies between dominant and non-dominant arms, an opportunity exists for a performance-enhancing programme to be implemented so that ambidexterity of the throwing skill can be improved.  相似文献   

16.
Adult overhead athletes without a history of shoulder injury show scapular adaptations. There is a lack of detailed assessment of scapular kinematics in junior overhead athletes. This study aims to investigate three-dimensional scapular kinematics in junior overhead athletes. We recruited a total of 20 junior tennis players and 20 healthy children without participation in any overhead sports in this study. Bilateral scapular kinematic data were recorded using an electromagnetic tracking device for scapular plane glenohumeral elevation. The data were further analysed at 30°, 45°, 60°, 90° and 120° during glenohumeral elevation and lowering. Statistical comparisons of the data between groups (junior overhead athletes and non-overhead athletes) and sides (serve dominant and non-dominant shoulders of the overhead athletes) were analysed with the ANOVA. Comparisons showed that, in general, the scapula was more upwardly rotated and anteriorly tilted in overhead athletes when compared to non-overhead athletes, however there was no side-to-side differences when serve dominant and non-dominant shoulders compared in junior overhead athletes. The serve dominant arm of junior overhead athletes had alternations in scapular kinematics when compared with the non-overhead athletes. These findings provide clinical evaluation implications and the need for clinicians to assess for potential adaptations in junior overhead athletes.  相似文献   

17.
棒球投手肩关节旋转运动特征研究   总被引：4，自引：0，他引：4  
棒球比赛中,投手是一支球队的灵魂,在很大程度上决定全局的比赛。肩部力量素质和活动范围是投手有效投球的基础,在很大程度上决定投球技术、机能的发挥。肩关节既是躯干和上肢的连结点,又是上肢运动的支点,是保证上肢完成三维活动的重要结构[1]。因此,肩关节在棒球运动中发挥着  相似文献   

18.
Previous studies suggested that a pronounced weakness of the extensor muscles relative to the flexor muscles could increase the risk of occurrence of lateral epicondylalgia. This study investigates this hypothesis by estimating the ratio of extensor to flexor muscle capacities among healthy non-players (n = 10), healthy tennis players (n = 20), symptomatic players (n = 6), and players who have recovered from lateral epicondylalgia (n = 6). Maximum net joint moments in flexion or extension were measured during seven tasks involving the voluntary contraction of wrist and fingers. Using these data, the muscle capacities of the main muscle groups of the hand (wrist flexors, wrist extensors, finger flexors, finger extensors, and intrinsic muscles) were estimated using a musculoskeletal model. These capacities were then used to compute the extensor/flexor capacity ratios about the wrist and the finger joints. Compared to healthy non-players, healthy players presented higher extensor muscle capacities and greater capacity ratios showing that playing tennis generates specific adaptations of muscle capacities. Interestingly, symptomatic players, similar to those of non-players, showed more imbalanced ratios than healthy players. These results confirm that the ratio of extensor/flexor muscle capacities seems to be associated with lateral epicondylalgia and can be further used to understand its incidence and consequences.  相似文献   

19.
The relationships between muscle fibre characteristics and the physical performance capacity of trained athletic boys (aged 11-13 years) were studied over 2 days. The subjects were divided into two groups according to muscle fibre distribution. The 'fast' group (FG) comprised 10 subjects (sprinters, weightlifters, tennis players) with more than 50% fast-twitch fibres (type II), and the 'slow' group (SG) comprised 8 subjects (endurance runners, tennis players, one weightlifter) with more than 50% slow-twitch fibres (type I) in their vastus lateralis muscle. The 'fast' group had 59.2 +/- 6.3% and the 'slow' group had 39.4 +/- 9.8% type II fibres. Other clear differences (P less than 0.05-0.01) between the groups were observed as regards reaction time, rate of force development and rise of the body's centre of gravity in the squatting jump. For these variables, the 'fast' group was superior to the 'slow' group. Muscle fibre distribution (% type II) correlated (P less than 0.05-0.01) negatively with reaction time. Muscle fibre area (% type II) correlated negatively with reaction time (P less than 0.05-0.001) and positively with chronological age (P less than 0.05) height (P less than 0.05), mass (P less than 0.001), serum testosterone (P less than 0.05), force production (P less than 0.05-0.01) and blood lactate (P less than 0.05) in the 60-s maximal anaerobic test. There were no significant correlations between muscle fibre characteristics and maximal oxygen uptake. The present study assumes that heredity partly affects the selection of sporting event. Growth, development and training are associated with muscle fibre area, which affects the physical performance capacity of the neuromuscular system in trained young boys.  相似文献   

20.
目的探讨高频正弦波振动(HFV)对制动大鼠比目鱼肌(SOL)梭内、外肌纤维肌球蛋白重链(MHC)表达的影响。方法采用大鼠后肢制动作为废用性肌萎缩动物模型,对振动组大鼠施以HFV,用免疫组化染色法检测大鼠SOL梭内、外肌纤维MHC表达。结果①制动14 d后,大鼠SOL梭外肌Ⅰ型肌纤维的构成比明显减少,Ⅱ型肌纤维的构成比明显增加(P<0.05),SOL梭内肌纤维快缩型MHC的表达有所增强;②制动加HFV大鼠与制动组相比,SOL梭外肌Ⅰ型肌纤维的构成比明显上升,Ⅱ型肌纤维的构成比明显下降(P<0.05),SOL梭内肌纤维快缩型MHC的表达没有明显变化。结论 HFV对制动大鼠SOL梭外肌Ⅰ型肌纤维向Ⅱ型肌纤维的转化和梭内肌MHC表达增强的趋势有明显的对抗作用。  相似文献   

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