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1.
D E Sherwood 《Research quarterly for exercise and sport》1991,62(3):302-308
When subjects make simultaneous aiming movements of the upper limbs over different distances, assimilation effects are shown; the shorter distance limb overshoots when paired with a longer distance limb. However, it is not known whether assimilation effects are due to variations in distance per se or to variations in target location. To separate the possible influences of distance and location, 60 subjects made rapid bimanual aiming movements in one of four conditions. The two different-distance groups made a 20 degrees movement in the left hand and a 60 degrees movement in the right hand to either the same or different target locations. The comparison groups moved 20 degrees in each limb. Somewhat surprisingly, spatial assimilations were greater when moving different distances to the same, rather than different, target locations, which suggests interlimb differences in distance mediate assimilation effects rather than target location. Temporal assimilations were greater when distance and location were varied, but the assimilations were not related to interlimb differences in velocity, as predicted by Marteniuk and MacKenzie (1980). 相似文献
2.
Louis R. Osternig James A. Sawhill Barry T. Bates Joseph Hamill 《Research quarterly for exercise and sport》2013,84(3):252-256
Abstract This study verified earlier anecdotal evidence indicating that spatial assimilations could be reduced by offsetting movements in time. In Experiment 1, 40 right-handed participants (ages 18–23 years) made single and dual quick lever reversals of 20° and 60° with the left and right limbs, respectively. Participants were assigned to either the Overlapping (O) group, in which one limb began when the other limb reached the reversal point, or to the Sequential (S) group in which one limb followed the other with a delay of 114 ms, on average. The shorter-distance limb of the O group overshot relative to the S group. Short-distance spatial assimilations were also shown in the S group in Experiment 2, when the delay was increased to 250, 500, or 1,500 ms (N = 30), suggesting that assimilation effects can be caused by command interactions at both the planning and the execution levels. 相似文献
3.
This study verified earlier anecdotal evidence indicating that spatial assimilations could be reduced by offsetting movements in time. In Experiment 1, 40 right-handed participants (ages 18-23 years) made single and dual quick lever reversals of 20 degrees and 60 degrees with the left and right limbs, respectively. Participants were assigned to either the Overlapping (O) group, in which one limb began when the other limb reached the reversal point, or to the Sequential (S) group in which one limb followed the other with a delay of 114 ms, on average. The shorter-distance limb of the O group overshot relative to the S group. Short-distance spatial assimilations were also shown in the S group in Experiment 2, when the delay was increased to 250, 500, or 1,500 ms (N = 30), suggesting that assimilation effects can be caused by command interactions at both the planning and the execution levels. 相似文献
4.
T. Gilmour Reeve Lanie A. Dornier Daniel J. Weeks 《Research quarterly for exercise and sport》2013,84(3):284-290
Abstract To investigate whether spatial assimilation effects are due to premovement control processes or postinitiation feedback processes, surface EMG recordings were made from two agonists and one antagonist during both single and dual movements involving the upper limb(s). In the single condition, subjects (N=7) made 25 Short (20°) and 25 Long (60°) reversal movements using levers in the sagittal plane, in 195 ms to reversal. In the dual condition, both Short and Long movements were performed simultaneously for 75 trials, the last 25 of which were without knowledge of results. Subjects overshot the Short target in the dual condition, showing spatial assimilation effects. Overshooting was associated with increased peak EMG in the initial (premovement) agonist burst, supporting the notion that spatial assimilation effects are modulated via premovement control processes. 相似文献
5.
This review summarizes research conducted in our laboratories over the past 5 years aimed at determining the temporal and spatial relationships between eye and hand movements and the amount of central processing that must occur before performing a manual aiming movement, relative to the amount of processing that is done online. All of our research to date points to a two-component model of speed-accuracy control in manual aiming. Several studies have shown that eye and hand movements in manual aiming are inextricably linked both temporally and spatially. Typically, the eye arrives in the vicinity of the target first; this coincides with peak acceleration of the finger during the initial impulse phase of a movement. There is also significant temporal and spatial coupling of the finger, elbow and shoulder in aiming, and movements appear to evolve in a proximal-to-distal fashion. Movements are endpoint driven and variability is reduced with distal approximation to the target. This movement control strategy means that visual information is not only available for use in modifying responses, but there is sufficient time available for its use. In sequential complex aiming movements, the use of visual feedback and on-line processing become even more important. Practice does not diminish the need for on-line processing; rather, its use appears to ensure greater movement efficiency. 相似文献
6.
This review summarizes research conducted in our laboratories over the past 5 years aimed at determining the temporal and spatial relationships between eye and hand movements and the amount of central processing that must occur before performing a manual aiming movement, relative to the amount of processing that is done online. All of our research to date points to a two-component model of speed-accuracy control in manual aiming. Several studies have shown that eye and hand movements in manual aiming are inextricably linked both temporally and spatially. Typically, the eye arrives in the vicinity of the target first; this coincides with peak acceleration of the finger during the initial impulse phase of a movement. There is also significant temporal and spatial coupling of the finger, elbow and shoulder in aiming, and movements appear to evolve in a proximal-to-distal fashion. Movements are endpoint driven and variability is reduced with distal approximation to the target. This movement control strategy means that visual information is not only available for use in modifying responses, but there is sufficient time available for its use. In sequential complex aiming movements, the use of visual feedback and on-line processing become even more important. Practice does not diminish the need for on-line processing; rather, its use appears to ensure greater movement efficiency. 相似文献
7.
Daniel M. Corcos 《Research quarterly for exercise and sport》2013,84(2):117-122
Abstract The purpose of this study was to investigate the discrepancy between the finding that when two hands make movements to targets of different distances, they have the same movement time (Kelso, Southard & Goodman, 1979a, b) and the finding that they have different movement times (Marteniuk & MacKenzie, 1980). The present experiment shows that when the ratio of the distance traveled by the two hands is 4:1, they do not take the same time. The hand moving the shorter distance lakes less time, although it takes more lime than when moving alone or when moving the same distance as the other hand. This finding is highlighted when individual data are examined. It appears that there is no difference between using homologous or nonhomologous muscle groups. 相似文献
8.
The control of human limb movement has been the focus of research for more than a century. A major issue to emerge from this work is the manner in which the central nervous system regulates electromyographic (EMG) activity to produce movements that differ in distance, velocity, and movement time. However the different methods of analysis often used to analyze EMG data could result in different kinematic-EMG relationships. In this study, participants performed an elbow flexion task to one of five distance goals (between 5 degrees and 50 degrees) using three movement speeds. EMG data from the right elbow flexors were compared using a trial-by-trial analysis and one based on averaged data. Averaging across trials underestimated biceps EMG amplitude at all movement distances and speeds compared to a trial-by-trial analysis. Averaging overestimated EMG burst duration compared to the trial-by-trial analysis. Peak agonist EMG amplitude was positively related to distance and inversely related to movement time. Agonist EMG duration was constant for movement distances less than 30 degrees but increased in the 50 degrees condition. The results support the view that peak EMG amplitude and duration can be controlled independently, but EMG duration changes only for longer distance movements when additional force is required. 相似文献
9.
Warren D. Walsh 《Research quarterly for exercise and sport》2013,84(3):368-379
Abstract The present experiment investigated the recall of terminal location and distance of both preselected and constrained short movements (12 cm ± 4 cm approximately) following 5 second and 30 second unfilled retention intervals. Systematic alteration of the magnitude and direction of the starting position for recall movements revealed that the distance moved markedly interfered with the recall of the terminal location, but distance was essentially recalled independently of terminal location. Recall of distance was superior to terminal location for both the unfilled retention intervals, and there was a decrease in location recall performances following the longer 30 second delay when compared to recall attempts after the shorter 5 second delay. The Findings are discussed in terms of recent proposals to account for the memory for, and control of, discrete limb movements. 相似文献
10.
While motor dominance appears to drive limb selection for reaching movements at the midline and ipsilateral (dominant) side, this study examined the possible determinants associated with what drives the programming of movements in response to stimuli presented in contralateral space. Experiment 1 distinguished between object proximity and a hemispheric bias for using the hand on the same side as the stimulus by comparing imagined and actual reaching with arms uncrossed and crossed. Experiment 2 examined the role of comfort in limb selection via participants reaching for a cube under two conditions: 1- and multiple-df movements. The first experiment demonstrated a proximity effect; participants preferred to keep their arms crossed to reach with the hand closest to the stimulus rather than uncrossing their arms to support a bias. Comfort was eliminated when participants continued to prefer the nondominant hand, even though they were able to reach with the dominant hand at all positions using only a 1-df movement. In summary, we offer evidence suggesting that limb selection in response to stimuli presented in contralateral hemispace is determined primarily by information related to the proximity between the stimulus and the hand. 相似文献
11.
Patrick F. Parks 《Research quarterly for exercise and sport》2013,84(4):346-351
Abstract The physical stimulus-psychological response relationship has been described as being either a prothetic or a metathetic continuum. That is, as the stimulus intensity increases, the response magnitude increases (prothetic) or stays the same (metathetic). The first experiment of this study considered this relationship for a movement having the final limb position, or location, as its goal. The second experiment focused on an extent movement. Subjects were tested on a linear positioning apparatus in both experiments using the method of constant stimuli for determining thresholds. On the basis of the Weber ratios and the JND's for the three increasing movement locations and extents, a metathetic continuum was determined as best describing location movements, while a prothetic continuum was considered more appropriate for extent movements. JND's indicated sensitive discrimination for location movements (1.08 to 1.39 cm for 25 to 75 cm locations) and less precise discrimination capability for extent movements (2.49 to 5.76 cm for 25 to 75 cm extents). Results are discussed in terms of their possible implications for addressing issues related to mechanisms subserving active kinesthesis, and in terms of their implications for experimental procedures for learning and memory investigations using discrete positioning responses. 相似文献
12.
Abstract Effects of movement context upon the encoding of kinesthetic spatial location information were examined in a series of experiments using a motor learning paradigm. A cross-modal, kinesthetic to kinesthetic plus visual feedback procedure was used in each experiment to determine the encoding characteristics of spatial information within a variety of movement conditions. Following knowledge of results trials, subjects performing in cross-modal conditions had significant directional errors (overshooting of the target) for spatial locations associated with specific and non-specific body-referents (Experiment 1), for different movement directions to the same target (Experiment 2), and for long (40 cm) movements (Experiments 2, 3) and short (15 cm) movements (Experiment 4). However, subjects in both intermodal and intramodal conditions who switched movement direction had significant undershooting of the spatial targets (Experiment 3). Movement context in terms of response endpoint location or movement length did not have an apparent effect on directional errors. Performances in all experimental conditions were biased in the direction of the movement during learning. The context provided by movement direction did influence the encoding of kinesthetic spatial information. 相似文献
13.
Using plain white and chequered footballs, we evaluated observers’ sensitivity to rotation direction and the effects of ball texture on interceptive behaviour. Experiment 1 demonstrated that the maximal distance at which observers (n = 8) could perceive the direction of ball rotation decreased when rotation frequency increased from 5 to 11 Hz. Detection threshold distances were nevertheless always larger for the chequered (decreasing from 47 to 28 m) than for the white (decreasing from 15 to 11 m) ball. In Experiment 2, participants (n = 7) moved laterally along a goal line to intercept the two balls launched with or without ±4.3 Hz sidespin from a 30-m distance. The chequered ball gave rise to shorter movement initiation times when trajectories curved outward (±6 m arrival positions) or did not curve (±2 m arrival positions). Inward curving trajectories, arriving at the same ±2 m distances from the participants as the non-curving trajectories, evoked initial movements in the wrong direction for both ball types, but the amplitude and duration of these reversal movements were attenuated for the chequered ball. We conclude that the early detection of rotation permitted by the chequered ball allowed modulation of interception behaviour without changing its qualitative characteristics. 相似文献
14.
Marcela Munera William Bertucci Sebastien Duc Xavier Chiementin 《Sports biomechanics / International Society of Biomechanics in Sports》2016,15(4):409-428
Whole body vibration (WBV) is used as a training method but its physical risk is not yet clear. Hence, the aim of this study is to assess the exposure to WBV by a measure of acceleration at the lower limb under dynamic and static postural conditions. The hypothesis of this paper is that this assessment is influenced by the frequency, position, and movement of the body. Fifteen healthy males are exposed to vertical sinusoidal vibration at different frequencies (20–60 Hz), while adopting three different static postures (knee extension angle: 180°, 120° and 90°) or performing a dynamic half-squat exercise. Accelerations at input source and at three joints of the lower limb (ankle, knee, and hip) are measured using skin-mounted accelerometers. Acceleration values (g) in static conditions show a decrease in the vibrational dose when it is measured at a more proximal location in the lower extremity. The results of the performed statistical test show statistically significant differences (p < 0.05) in the transmissibility values caused by the frequency, the position, and to the presence of the movement and its direction at the different conditions. The results confirm the initial hypothesis and justify the importance of a vibration assessment in dynamic conditions. 相似文献
15.
To investigate whether spatial assimilation effects are due to premovement control processes or postinitiation feedback processes, surface EMG recordings were made from two agonists and one antagonist during both single and dual movements involving the upper limb(s). In the single condition, subjects (N = 7) made 25 Short (20 degrees) and 25 Long (60 degrees) reversal movements using levers in the sagittal plane, in 195 ms to reversal. In the dual condition, both Short and Long movements were performed simultaneously for 75 trials, the last 25 of which were without knowledge of results. Subjects overshot the Short target in the dual condition, showing spatial assimilation effects. Overshooting was associated with increased peak EMG in the initial (premovement) agonist burst, supporting the notion that spatial assimilation effects are modulated via premovement control processes. 相似文献
16.
加快掌握高难动作是女子跳马发展的趋向,掌握两个不同类型的10分起评动作,是优秀选手发展的重点。女子跳马技术的发展,仍将集中在"踺子后空翻"、"侧手翻"、"前手翻"和"踺子转体"四种类型的动作上,以"直体"完成不同类型的两种动作,是当今女子跳马动作选择的主要特征。"前手翻类"动作的发展潜力和"踺子后手翻类"动作的完成力度将加大,"踺子转体类"动作的完成将倾向"转体180°";而采用"笠松"侧手翻来尽快提高跳马动作完成难度的选手将会增多;确保动作质量及落地稳定是跳马比赛夺冠的关键。 相似文献
17.
Abstract Schmidt's (1975) schema theory was tested with subjects who had to emit a rapid aiming response while wearing prism glasses. The glasses enabled them to view the target, but not their responding limb or the outcome of the movement. The problem was to determine the effect of (a) training with variable target practice, and (b) experiencing visual displacement information of the target, prior to training, on performance in transfer to a novel target distance. A 2 × 2 (type of practice × displacement information) factorial design was used, in which four groups of 15 male college subjects performed 60 training trials with verbal knowledge of results. The groups with variable target practice had less error on initial transfer to the novel target and throughout transfer than the groups with nonvariable target practice. No evidence was found to indicate that rate of learning for a novel target distance during transfer in the absence of KR is a positive function of the variability of target practice in training. Nor was any effect found for experiencing visual displacement information on performance in transfer. 相似文献
18.
Elmar Weltin Albert Gollhofer Guillaume Mornieux 《European Journal of Sport Science》2016,16(2):182-189
In lateral reactive movements, core stability may influence knee and hip joint kinematics and kinetics. Insufficient core stabilisation is discussed as a major risk factor for anterior cruciate ligament (ACL) injuries. Due to the higher probability of ACL injuries in women, this study concentrates on how gender influences trunk, pelvis and leg kinematics during lateral reactive jumps (LRJs). Perturbations were investigated in 12 men and 12 women performing LRJs under three different landing conditions: a movable landing platform was programmed to slide, resist or counteract upon landing. Potential group effects on three-dimensional trunk, pelvic, hip and knee kinematics were analysed for initial contact (IC) and the time of peak pelvic medial tilt (PPT). Regardless of landing conditions, the joint excursions in the entire lower limb joints were gender-specific. Women exhibited higher trunk left axial rotation at PPT (women: 4.0 ± 7.5°, men: ?3.1 ± 8.2°; p = 0.011) and higher hip external rotation at both IC and PPT (p < 0.01). But women demonstrated higher knee abduction compared to men. Men demonstrated more medial pelvic tilt at IC and especially PPT (men: –5.8 ± 4.9°, women: 0.3 ± 6.3°; p = 0.015). Strategies for maintaining trunk, pelvis and lower limb alignment during lateral reactive movements were gender-specific; the trunk and hip rotations displayed by the women were associated with the higher knee abduction amplitudes and therefore might reflect a movement strategy which is associated with higher injury risk. However, training interventions are needed to fully understand how gender-specific core stability strategies are related to performance and knee injury. 相似文献
19.
Anne-Line Balduck Marc Buelens Renaat Philippaerts 《Research quarterly for exercise and sport》2013,84(3):379-383
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
20.
Hiromu Katsumata Keita Himi Tenpei Ino Kyohei Ogawa Takehiro Matsumoto 《Journal of sports sciences》2017,35(24):2468-2480
Baseball batters must react to pitches delivered to different locations within the strike zone by modulating their movements. In tee-batting practice, such batters place a ball on a tee stand at a location, where they intend to hit the ball, assuming a particular pitch’s trajectory. In the present study, we analysed three-dimensional movements in tee-batting to identify characteristics of the batters’ intended impact locations across the strike zone, thereby investigating spatiotemporal features of movement modulation. More specifically, 10 experienced baseball batters performed tee-batting at their preferred impact locations at nine different heights and courses within the strike zone. The distribution of impact locations showed regularity, i.e., the location shifted forward for balls placed high and inside, while it shifted backward for balls placed low and outside. Furthermore, trunk and arm movements showed systematic modulation as the impact locations changed. The duration of bat movement was also location dependent, i.e., hitting the inside ball took more time than hitting the outside ball. Our results indicate that even though movements among body segments were properly coordinated to adjust the bat swing for different impact locations, fine timing adjustments were also required to hit the ball at those preferred impact locations and therefore properly react to differences in flight paths. 相似文献