A Time-Motion Analysis of the Cross-Over Step Block Technique in Volleyball: Non-Linear and Asymmetric Performances

Blocking performance in volleyball is strongly affected by the time in which the action is executed. This study analyzes the time-motion variables in terms of the player’s role and movement direction (right or left), in different phases of the displacement and jump actions in the cross-over step block technique. A kinematic analysis was conducted with 10 senior male volleyball players. Two series of five repetitions were each recorded and classified in terms of middle-blockers (block in the center and sides of the net) and wing-players (only block in the sides). The results showed that the middle-blockers were significantly slower than the wing-players in the first (0.75 ± 0.24 vs. 0.66 ± 0.19 sec; p = 0.020; ES = −0.37 ± 0.30) and fourth phases (0.33 ± 0.8 vs. 0.29 ± 0.8 sec; p = 0.001; ES = −0.44 ± 0.31), and in the total time for blocking (3.15 ± 0.6 vs. 3 ± 0.58 sec; p = 0.003; ES = −0.23 ± 0.31). Overall, players were significantly faster when moving to the right side, showing performance asymmetries. The fastest phases were also performed just before the jump. These findings provide specific knowledge about the cross-over step block technique in its different phases and displacement direction. This information can be used to improve the movement time in the first defensive action in volleyball.

Download Full-text

Wheelchair Racquetball: A Preliminary Time Motion Analysis

Adapted Physical Activity Quarterly ◽

10.1123/apaq.7.4.370 ◽

1990 ◽

Vol 7 (4) ◽

pp. 370-384

Author(s):

Colin Higgs

Keyword(s):

Motion Analysis ◽

Time Motion ◽

The Right

Wheelchair racquetball players in the A and B divisions of the 1989 Canadian Racquetball Championships were videotaped and their performances were analyzed. The results indicated that the athletes had an exercise-to-pause ratio of 1:1.5 at the A level and 1:2.3 at the B level. Rallies were slightly longer at the higher level, with substantially longer pause periods at the B level. There was a higher percentage of longer rallies at the A level, although both divisions of play had comparable percentages of forehand and backhand shots. A-level players demonstrated greater distances covered per rally, greater wheelchair speed, and a higher degree of wheelchair maneuverability measured by the number and magnitude of directional changes. In particular, A-level players showed a greater tendency to use small directional corrections, particularly turns to the right of less than 45 °. It is suggested that this action allowed a less restricted backswing for powerful forehand shots.

Download Full-text

NEONATES ADMITTED TO THE NEONATAL INTENSIVE CARE UNIT IN GUJARAT, INDIA: A TIME-MOTION ANALYSIS OF THE MOTHERS STAYING IN THE NEONATAL UNIT

10.26226/morressier.57d034d0d462b802923833d9 ◽

2016 ◽

Author(s):

Dharti Patel

Keyword(s):

Intensive Care Unit ◽

Intensive Care ◽

Neonatal Intensive Care Unit ◽

Motion Analysis ◽

Neonatal Intensive Care ◽

Neonatal Unit ◽

Time Motion

Download Full-text

Longitudinal oscillation of a rod with a variable cross section

Multiphase Systems ◽

10.21662/mfs2019.2.019 ◽

2019 ◽

Vol 14 (2) ◽

pp. 138-141

Author(s):

I.M. Utyashev

Keyword(s):

Cross Section ◽

Natural Frequencies ◽

Liouville Problem ◽

Variable Cross Section ◽

Variable Cross ◽

Longitudinal Vibrations ◽

Cross Sectional ◽

Independent Functions ◽

The Cross ◽

The Right

Variable cross-section rods are used in many parts and mechanisms. For example, conical rods are widely used in percussion mechanisms. The strength of such parts directly depends on the natural frequencies of longitudinal vibrations. The paper presents a method that allows numerically finding the natural frequencies of longitudinal vibrations of an elastic rod with a variable cross section. This method is based on representing the cross-sectional area as an exponential function of a polynomial of degree n. Based on this idea, it was possible to formulate the Sturm-Liouville problem with boundary conditions of the third kind. The linearly independent functions of the general solution have the form of a power series in the variables x and λ, as a result of which the order of the characteristic equation depends on the choice of the number of terms in the series. The presented approach differs from the works of other authors both in the formulation and in the solution method. In the work, a rod with a rigidly fixed left end is considered, fixing on the right end can be either free, or elastic or rigid. The first three natural frequencies for various cross-sectional profiles are given. From the analysis of the numerical results it follows that in a rigidly fixed rod with thinning in the middle part, the first natural frequency is noticeably higher than that of a conical rod. It is shown that with an increase in the rigidity of fixation at the right end, the natural frequencies increase for all cross section profiles. The results of the study can be used to solve inverse problems of restoring the cross-sectional profile from a finite set of natural frequencies.

Download Full-text

Ten Articles on the Freedom and Service of the Church

Scottish Journal of Theology ◽

10.1017/s0036930600054089 ◽

1966 ◽

Vol 19 (4) ◽

pp. 385-398

Keyword(s):

Right Hand ◽

The Cross ◽

The Right ◽

The Church

‘Looking to Jesus the pioneer and perfecter of our faith, who for the joy that was set before him endured the cross, despising the shame, and is seated at the right hand of God. Consider him who endured from sinners such hostility against himself, so that you may not grow weary or fainthearted.’ (Heb. 12.2–3.)

Download Full-text

The Essence of Christianity and the Cross of Christ

Harvard Theological Review ◽

10.1017/s0017816000012578 ◽

1914 ◽

Vol 7 (4) ◽

pp. 538-594

Author(s):

Benjamin B. Warfield

Keyword(s):

New Haven ◽

Liberal Theology ◽

Religious System ◽

The World ◽

Cross Of Christ ◽

The Face ◽

Divinity School ◽

The Common ◽

The Cross ◽

The Right

In a recent number of The Harvard Theological Review, Professor Douglas Clyde Macintosh of the Yale Divinity School outlines in a very interesting manner the religious system to which he gives his adherence. For “substance of doctrine” (to use a form of speech formerly quite familiar at New Haven) this religious system does not differ markedly from what is usually taught in the circles of the so-called “Liberal Theology.” Professor Macintosh has, however, his own way of construing and phrasing the common “Liberal” teaching; and his own way of construing and phrasing it presents a number of features which invite comment. It is tempting to turn aside to enumerate some of these, and perhaps to offer some remarks upon them. As we must make a selection, however, it seems best to confine ourselves to what appears on the face of it to be the most remarkable thing in Professor Macintosh's representations. This is his disposition to retain for his religious system the historical name of Christianity, although it utterly repudiates the cross of Christ, and in fact feels itself (in case of need) quite able to get along without even the person of Christ. A “new Christianity,” he is willing, to be sure, to allow that it is—a “new Christianity for which the world is waiting”; and as such he is perhaps something more than willing to separate it from what he varyingly speaks of as “the older Christianity,” “actual Christianity,” “historic Christianity,” “actual, historical Christianity.” He strenuously claims for it, nevertheless, the right to call itself by the name of “Christianity.”

Download Full-text

Kinematic design and motion analysis of spatial rapier drive mechanisms used in weaving machines

Textile Research Journal ◽

10.1177/0040517514534754 ◽

2014 ◽

Vol 84 (19) ◽

pp. 2065-2073 ◽

Cited By ~ 1

Author(s):

Recep Eren ◽

Mesrur Erturk ◽

Barıs Hascelik

Keyword(s):

Motion Analysis ◽

Kinematic Analysis ◽

Gear Ratio ◽

Main Shaft ◽

Drive Mechanism ◽

Spatial Mechanism ◽

Kinematic Design ◽

Shaft Angle

This paper presents an approach for the kinematic design of a rapier drive mechanism containing a spatial mechanism and analyses rapier motion curve. Kinematic design and analysis equations are derived and then the link lengths of the spatial mechanism are calculated in order to satisfy the critical rapier positions inside and outside the shed. In this way, the portions of one loom revolution, during which the rapiers are inside and outside the shed, are determined. The rapier motion curve is obtained by using kinematic analysis equations. It is shown that the position of the oscillating link in the spatial mechanism and the loom main shaft angle at which the rapier enters the shed have the most significant effect on the rapier motion curve. The gear ratio has also some effect on the rapier motion curve. Different rapier motion curves are obtained by changing these parameters and the suitability of these curves for rapier motion is discussed.

Download Full-text

XXXIV. The Episcopal Coins of Durham, and the Monastic Coins of Reading, minted during the Reigns of Edward I. II. and III. appropriated to their respective Owners. By Benjamin Bartlet, F.A.S.

Archaeologia ◽

10.1017/s026134090001496x ◽

1779 ◽

Vol 5 ◽

pp. 335-339

Author(s):

Benjamin Bartlet

Keyword(s):

The Other ◽

The Cross ◽

The Right ◽

Pastoral Staff ◽

Edward I

We find amongst the coins minted at Durham, during the reigns of the three first Edwards, several pennies bearing particular marks in some one or other part of the coin: one has a cross moline at the beginning of the legend on each side of the piece; a second has the same cross in the second quarter of the reverse; a third has it at the beginning of the legend on the obverse only; another has a lion rampant betwixt two fleurs de lis in the same place. Some of these being placed where in succeeding reigns the mint mark stood, have been taken notice of by two writers on these subjects, but no reasons assigned for their use. There are also from the same mint two others, which have the upright limb of the cross turned in the form of a pastoral staff, one of them to the right, the other to the left; they are said to have come from the bishops mint, but the prelates name are not mentioned.

Download Full-text