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1.
Abstract

Forearm flexion strength of 65 college men was measured at two distances from the elbow at each of three angles of the forearm. The speed of forearm flexion movement was measured through an arc of 85°. Ebel intraclass reliabilities for strength and speed were high, i.e., .95 to .99. The extremely low correlations between limb strength and speed of movement, which ranged from —.06 to .14, are in agreement with the majority of the low correlations reported in earlier studies. The findings of this study support the theory of specificity in that individual differences in the speed of a limb involving a single joint are predominantly independent of strength measures associated with that limb and joint.  相似文献   

2.
Abstract

The purpose of this study was twofold: to determine which exercise program was most effective in producing a static strength gain and to determine the relationship between static strength and speed of movement. Seventy-two eighth grade girls were divided into two experimental groups one using an isometric exercise program, the other using an isotonic program. A control group played lead-up games during the experimental period. Strength and speed of the arm and shoulder girdle were both measured by three tests. Prior to training, correlations indicated a rather high relationship between static strength, and speed of a dominant arm movement. Following training there was little relationship between static strength, and speed of a specific arm movement. The results of the training program indicated an increase in mean performance in all three groups with the isotonic group being superior.  相似文献   

3.
Abstract

The following measures were recorded for third- and sixth-grade children: height; weight; grip strength of the dominant and nondominant hands; elbow flexion and elbow extension strength; hip flexion and hip extension strength; dynamic balance; ball-throwing accuracy; speed of hand-arm movement; eye-hand coordination; stimulus discrimination and hand speed; perceptual ability; academic achievement; and intelligence. It was concluded that sixth-grade boys had, in general, the most favorable recorded measures, followed by sixth-grade girls, third-grade boys, and third-grade girls, these differences usually being significant.  相似文献   

4.
Abstract

The purpose of this investigation was to determine the yearly changes in body composition as well as absolute and relative isokinetic forearm flexion and extension strength of high school wrestlers. Evaluations of body composition (underwater weighing) were performed on 27 high school wrestlers prior to three consecutive seasons. In addition, isokinetic forearm flexion and extension strength values at 180°/s (Cybex II) were available for 20 of the subjects. The mean ages at the times of laboratory testing were 15.5 (± .5), 16.5 (± .5), and 17.5 (± .5) years. Repeated measures ANOVA or ANCOVA with Tukey post-hoc comparisons were used to locate significant (p<.05) differences across age for height, body weight, relative fat, body density, fat weight, fat-free weight, absolute muscular strength, and muscular strength covaried for body weight and fat-free weight. There were yearly increases in all variables except fat weight, forearm flexion covaried for fat-free weight and forearm extension covaried for fat-free weight. The results of this study indicated that the improved wrestling performance and the increase in weight classification which normally occurs during high school are, in part, a function of yearly changes in body composition and muscular strength.  相似文献   

5.
Abstract

The topspin tennis forehand drive has become a feature of modern game; yet, as compared to the serve, there has been little research analysing its kinematics. This is surprising given that there is considerably more variation in the execution of the topspin forehand. Our study is the first to examine the amplitude of upper limb joint rotations that produce topspin in the forehand drives of 14 male competitive tennis players using video-based motion analysis. Humerothoracic abduction (-)/adduction (+), extension (-) /flexion (+), and external (-)/internal (+) rotation, elbow extension (-) /flexion (+) and forearm supination (-)/pronation (+), wrist extension (-)/flexion (+) and ulnar (-)/radial (-) deviation were computed. Our findings revealed that the generation of topspin demanded more humeral extension and forearm pronation but less humeral internal rotation angular displacement during the forwardswing. The follow-through phase of the topspin shot was characterised by greater humeral internal rotation and forearm pronation, and reduced humeral horizontal adduction when compared to the flat shot. This study provides practitioners with a better understanding of the upper limb kinematics associated with the topspin tennis forehand drive production to help guide skill acquisition interventions and physical training.  相似文献   

6.
Abstract

The purpose of this study was to analyze the relative endurance ability of women in terms of muscle mass, static muscle strength, and critical occluding tension levels (COTL). Women physical education majors volunteered as subjects for this study (N = 56). The percentages of grip strength used for the relative endurance tests were 30%, 45%, 60%, and 75% with local circulation to the forearm muscles intact and artificially occluded by a pressure cuff. Analysis of the data revealed that there was no significant difference in the endurance times of high- and low-strength women. The relationship between grip strength and relative endurance time for each tension level was insignificant (r = ?.23 to ?.34). These findings were discussed in light of the relatively small differences in muscle mass and similarity in COTL of high- and low-strength women.  相似文献   

7.
Abstract

The aim of this study was to test the correlation between knee-to-hip flexion ratio during a single leg landing task and hip and knee strength, and ankle range of motion. Twenty-four male participants from a professional soccer team performed a continuous single leg jump-landing test during 10s, while lower limb kinematics data were collected using a motion analysis system. After biomechanical testing, maximal isometric hip (abduction, extension, external rotation), knee extension and flexion strength were measured. Maximum ankle dorsiflexion range of motion was assessed statically using the weight bearing lunge test. Pearson correlation coefficients were calculated to determine the associations between the predictor variables (knee and hip strength, and ankle ROM) and the main outcome measure (knee-to-hip flexion ratio). Correlation between knee-to-hip flexion ratio and hip abductors strength was significant (r = ?0.47; p = 0.019). No other significant correlations were observed among the variables (p > 0.05). These results demonstrated that a lower hip abductors strength in male soccer players was correlated with a high knee-to-hip flexion ratio during landing from a single leg jump, potentially increasing knee overload by decreasing energy absorption at the hip. The results provide a novel proposal for the functioning of hip muscles to control knee overload.  相似文献   

8.
Abstract

Tests were made with the hand carrying weights of 0.2, 3.1, and 16.6 kg. during a 72° horizontal adductive arm swing of maximal speed timed at 12° intervals. Five practice swings and 20 trials, under each condition, were performed by 60 male subjects. Reliability coefficients were high. The first 24° of movement exhibited declining acceleration, followed by linearly increasing acceleration for the 24°—60° interval and deceleration for the next 12°. Compared with static strength in the movement position, action strength computed from acceleration was much greater with the heaviest weight and considerably less with the light weights. The correlation between static strength and speed was quite low for the normal arm swing but increased with added weight, becoming r = .76 for the heaviest. There was little correlation of individual differences in speed between different phases of movement or between movements with light and heavy weights. Specificity was high, although correlations were made for attenuation.  相似文献   

9.
Abstract

Ages, heights, weights, and 24 static (cable tensiometer) strength test scores were obtained from 81 college men enrolled in service course classes at the University of Oregon during the 1963–64 academic year. Of the 276 intercorrelations between strength scores, 215 were significant (p > .01; r ≥ .285). In general, when age, height, and weight were held constant, the intercorrelations between the strength scores from the different segments of the body were not greatly changed from those of the zero-order correlations between the same strength scores. Five functional clusters or groupings of strength were isolated and identified by means of the application of cluster analysis to the intercorrelations between the strength tests and by an analysis of muscle actions involved in the performance of each of the strength tests. The findings in this study disclosed five clusters or groupings of strength which were specific to shoulder, trunk, neck, wrist, and hip joints. They could also be described as arm and forearm strength, trunk strength, neck strength, hand strength, and thigh and leg strength.  相似文献   

10.
Abstract

College men and women were tested as to reaction time and speed of an arm movement using both motor-oriented and stimulus-oriented set. The results confirmed a hypothesis based on neuromotor coordination theory that predicted slower movement and greater reaction latency when the motor set was used. However, the 20 percent of subjects who had a natural motor set tendency moved faster with an enforced motor set than with an enforced sensory set. The conditions of enforced set caused a moderate positive correlation between reaction and movement times. Women subjects reacted and moved slower than men, but were similarly influenced by the two enforced set conditions. Their natural set tendency was definitely stimulus-oriented, while men tended to have a neutral orientation.  相似文献   

11.
ABSTRACT

The skating acceleration to maximal speed transition (sprint) is an essential skill that involves substantial lower body strength and effective propulsion technique. Coaches and athletes strive to understand this optimal combination to improve performance and reduce injury risk. Hence, the purpose of this study was to compare body centre of mass and lower body kinematic profiles from static start to maximal speed of high calibre male and female ice hockey players on the ice surface. Overall, male and female skaters showed similar centre of mass trajectories, though magnitudes differed. The key performance difference was the male’s greater peak forward skating speed (8.96 ± 0.44 m/s vs the females’ 8.02 ± 0.36 m/s, p < 0.001), which was strongly correlated to peak leg strength (R 2 = 0.81). Males generated greater forward acceleration during the initial accelerative steps, but thereafter, both sexes had similar stride-by-stride accelerations up to maximal speed. In terms of technique, males demonstrated greater hip abduction (p = 0.006) and knee flexion (p = 0.026) from ice contact to push off throughout the trials. For coaches and athletes, these findings underscore the importance of leg strength and widely planted running steps during the initial skating technique to achieve maximal skating speed over a 30 m distance.  相似文献   

12.
In this study, we examined the relationship between upper limb joint movements and horizontal racket head velocity to clarify joint movements for developing racket head speed during tennis serving. Sixty-six male tennis players were videotaped at 200 Hz using two high-speed video cameras while hitting high-speed serves. The contributions of each joint rotation to horizontal racket velocity were calculated using vector cross-products between the angular velocity vectors of each joint movement and relative position vectors from each joint to the racket head. Major contributors to horizontal racket head velocity at ball impact were shoulder internal rotation (41.1%) and wrist palmar flexion (31.7%). The contribution of internal rotation showed a significant positive correlation with horizontal racket head velocity at impact (r = 0.490, P < 0.001), while the contribution of palmar flexion showed a significant negative correlation (r = ? 0.431, P < 0.001). The joint movement producing the difference in horizontal racket head velocity between fast and slow servers was shoulder internal rotation, and angular velocity of shoulder internal rotation must be developed to produce a high racket speed.  相似文献   

13.
Abstract

The experiment was designed to compare the effects of isometric-isotonic (A), dynamic-overload (B), and free swing (C) exercise programs on the speed and strength of a lateral arm movement The 26 college men in each group—three experimental and one control—were given pre- and post-training speed and strength trials. Each experimental group performed its assigned exercise twice a week during the 10-week training period. Reliability coefficients for both strength and speed of movement measurements were found to be high. Following training there were significant speed increases in both the isometric-isotonic and dynamic-overload groups (t=10.06 and 8.10; however, the difference in speed gain between conditions was nonsignificant (F=.10). Also, strength increases in both of these groups were significant (t=8.81 and 3.08), with that of the isometric-isotonic group significantly greater than the dynamic-overload group (F=5.11). No significant speed or strength gains were registered by either the free swing or control group.  相似文献   

14.
Abstract

Two groups of college men (N = 41) participated for 12 weeks in two different exercise programs to determine the relative effects of unilateral isometric and isotonic contractions of equal load, duration, and range of movement on the muscular strength of the contralateral limb. Data examined by the t test for correlated means indicated that both methods of exercise produced significant increases in the strength of the unexercised limb. Application of the multiple linear regression technique for covariance analysis revealed that no significant difference existed between the effectiveness of the exercise methods.  相似文献   

15.
Abstract

Speed of movement in a lateral adductive arm swing was timed at seven equidistant points on an arc of 120 degrees. Static strength and effective arm mass were measured in the movement position. Data obtained on 36 men and 36 women were subjected to a centroid factor analysis. The structure for both sexes consisted of a single common factor for arm speed and a substantial item-specific factor for the first 17 cm. of movement, suggesting that the velocity curve probably consisted of two components. The correlations between the strength/mass ratios and speeds of movement were almost zero, except in the middle phase of the action, where the relationship was .29 for men and .27 for women (.36 and .34 when corrected for attenuation). These very low correlations supported the hypothesis of neuromotor specificity. Circumferential speed for women was 17 percent slower than for men, partly because their arms were shorter. In angular speed, the sex difference was only 5 percent.  相似文献   

16.

The objectives of this study were to describe the volleyball spiking actions used by players in top‐level competition, and also to examine the interrelationships between upper limb, lower limb and whole body kinematic variables, and post‐impact ball speed in the spiking technique. Two Photosonics Biomechanics 500 cine‐cameras operating at a nominal frame rate of 100 Hz were used to film the spiking actions of 10 male senior international volleyball players at the XVI Universiade (1991 World Student Games). Three‐dimensional object space co‐ordinates of digitized image co‐ordinates were obtained using a DLT algorithm and an array of calibration points in the filmed volume. Relationships between lower limb angular kinematics at take‐off, centre of mass vertical velocity at take‐off and centre of mass vertical displacement (jump height) were examined. Relationships between angular kinematics of the hitting arm and post‐impact ball speed were also determined. The mean (± S.E.) centre of mass vertical velocity at take‐off was 3.59 ± 0.05 m s‐1 and the mean height jumped was 0.62 ± 0.02 m. As expected, a significant correlation was found between the square of the centre of mass vertical velocity at take‐off and jump height (r = 0.78; P <0.01). No significant correlations were found between lower limb angular kinematics and centre of mass vertical velocity at take‐off or jump height. The mean post‐impact ball speed was 27.0 ± 0.9 m s‐1, and this was significantly correlated to maximum right humerus angular velocity (r=0.75; P< 0.01). Trunk rotation angular kinematics and right elbow angular velocity did not correlate significantly with post‐impact ball speed. It was also noted that the majority of players filmed did not fit into any of the spiking categories identified in earlier studies.  相似文献   

17.
In this study, we examined the relationship between upper limb joint movements and horizontal racket head velocity to clarify joint movements for developing racket head speed during tennis serving. Sixty-six male tennis players were videotaped at 200 Hz using two high-speed video cameras while hitting high-speed serves. The contributions of each joint rotation to horizontal racket velocity were calculated using vector cross-products between the angular velocity vectors of each joint movement and relative position vectors from each joint to the racket head. Major contributors to horizontal racket head velocity at ball impact were shoulder internal rotation (41.1%) and wrist palmar flexion (31.7%). The contribution of internal rotation showed a significant positive correlation with horizontal racket head velocity at impact (r = 0.490, P < 0.001), while the contribution of palmar flexion showed a significant negative correlation (r = - 0.431, P < 0.001). The joint movement producing the difference in horizontal racket head velocity between fast and slow servers was shoulder internal rotation, and angular velocity of shoulder internal rotation must be developed to produce a high racket speed.  相似文献   

18.
Abstract

Plantar flexion and knee extension fatigue patterns elicited by 25 serial isometric contractions were assessed on eight female distance runners. Fiber type composition of the vastus lateralis and gastrocnemius muscles was examined by a needle biopsy technique. Two different isometric exercise regimens were administered: 10-sec contractions separated by 5-sec intertrial rest (10:5) designed to elicit a rapid rate of fatigue, and 10-sec contractions separated by 20-sec intertrial rest (10:20) designed to induce less fatigue. No fatigue pattern was found for the 10:20 regimen which was consistent with previous data on male distance runners but unlike male power athletes who did exhibit significant fatigue. Significant fatigue decrements were found for the 10:5 knee extension (55.7%) and plantar flexion (75.8%) conditions. Fiber type composition and fatigue decrements did not correlate. Knee extension and plantar flexion maximum strength correlated significantly with the amount of fatigue induced with r's of .82 and .83, respectively. For each separate muscle group, maximum isometric strength was a better predictor of fatigability than fiber type composition. Even though differences in maximal strength and muscle mass existed between knee extension and plantar flexion muscle groups, elicited fatigue curves were similar in pattern differing only in absolute level. High versus low strength classification analysis showed similar knee extension but dissimilar plantar flexion fatigue patterns. Results suggest that the role of fiber type composition, muscle mass, and maximum strength level as they influence local muscular fatigue patterns must be elucidated for each muscle group separately.  相似文献   

19.
The aim of this study was to compare the associations between lower limb biomechanics and ball release speed in 15 high-performance (HP) and 15 amateur fast bowlers. Kinematic and kinetic variables of the lower limbs collected in the laboratory environment with a 3D Vicon motion analysis system were compared between groups, as well as their associations with ball release speed. HP bowlers had a significantly higher run-up velocity at back foot impact but this difference became non-significant at ball release. Front knee kinematics were not statistically different, however effect sizes revealed medium-large differences with the HP group displaying a more extended knee joint at maximum flexion (d = 0.72) and ball release (d = 0.76). Only front hip positive power was significantly higher in the HP group and it was suggested that the probable cause was the HP bowlers having less knee flexion after front foot impact. From a joint power analysis, the extensor muscle groups of the hip and knee were shown to be important in developing ball release speed. This highlights the need for lower limb/core strength programmes to be multifaceted and focus on the muscles associated with both power and stability.  相似文献   

20.
PurposeThe purpose of this study was to examine the reliability and the learning effect of an isokinetic trunk flexion–extension protocol designed to simultaneously assess trunk muscle strength and endurance. In addition, the effect of the participants' sex on the reliability data was examined.MethodsFifty-seven healthy and physically active young men (n = 28) and women (n = 29) performed the isokinetic protocol 5 times, separated by a week between each of the first 4 sessions and by a month between the last 2 sessions. The protocol consisted of performing 4 trials of 15 maximum flexion–extension concentric exertions at 120°/s (range of trunk motion = 50°). The absolute and relative peak torque and total work were calculated to assess trunk flexion and extension strength. In addition, endurance ratio, modified endurance ratio, fatigue final ratio, recovery ratio, and modified recovery ratio variables were used for the assessment of trunk muscle endurance in both directions.ResultsRegarding the absolute reliability, no relevant changes were found between paired-comparison sessions for most strength and endurance variables, except for total work and relative total work variables in the flexion movement in both sexes. In addition, the typical error of the isokinetic variables was lower than 10% in both males and females, and minimum detectable changes ranged from 7% to 20%, with a tendency to be higher in females and in endurance variables. The strength variables showed high-to-excellent intraclass correlation coefficients (ICCs; >0.74); however, for the endurance variables only the endurance ratio and the modified endurance ratio obtained moderate-to-high ICC values (0.57 < ICC < 0.82). In addition, the analysis of the variance reported no significant differences between consecutive pairs of sessions for most variables in both sexes.ConclusionOverall, these findings provide clinicians, trainers, and researchers with a 10-min single-session protocol to perform a reliable muscle strength and endurance evaluation of trunk flexor and extensor muscles, all within the same protocol.  相似文献   

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