| Purpose:To compare the difference of action program, movement coordination, swing performance between athletes of different levels. Trying to explore how attention focus effect swing performance by changing movement control and the control differences caused by the sports level. Methods:Recruited subjects of golf major students from Shanghai University of Sports. All the subjects must have been training for over one year, have the ability to strike the ball far than 100 yards using No.7 brassie. 25 players(18 men, 7 women who are right-handed players) to participated, 16 players(11 men, 5 women who are right-handed golfer) were included as a subject in this experiment. The players were divided into two groups by the ball speed, there was no difference between low group(ball: 26.48 ± 1.03m/s) and high group(ball: 29.47± 1.60m/s). The players used their own 7-iron club to intercept net ball indoor, completed five times hitting a ball or fake ball or genuine ball, random sequence generated by Excel. Infrared cameras capture system(Vicon, UK), surface electromyography system(Delsys Inc. MA, USA) and force platform(Kistler, switzerland) were used to collect synchronous kinematic, EMG and kinetics data of swing, supplemented Visual3 D and other signal analysis software for post-processing and analysis of the raw data. One-way ANONA was used to compare the data under different conditions, paired T-test was used to compare the own difference of the subjects; Using Excel 2010 and SPSS 19.0 to conduct the statistical analysis, the significant level was set at p<0.05, the very significant level was set at p<0.01. Results:(1) The effect of ball on athletes head rotation angle and swing performanceIn no ball exercise, high speed athletes starting head rotation angle and no difference between true swing, the ball head rotation angle was significantly smaller than the true swing(p<0.01), the ball when the swing speed was significantly smaller than the true swing(p<0.05), with the essential stage of acceleration was significantly smaller than the real swing(p<0.01), the swing plane angle was significantly smaller than the real swing(p<0.05); low speed athletes starting head rotation angle was less than the true swing(p<0.05), the ball head rotation angle was less than the true swing(p<0.01), under the absolute time significantly better than the real wave length(p<0.01), with the wave of absolute time significantly better than the real swing short(p<0.05), with volatile relative time less than the true swing(p<0.05), deviation angle was less than the true swing Club(p<0.05).Fake ball practice ddi not affect the rotation angle of the head, high speed athletes with swing head acceleration was significantly less than that of true swing(p< 0.01), low speed athletes with volatile absolute time than true swing was significantly shorter(p < 0.05).(2) The characteristics of the speed control of the rod head during the no ball trainingHigh speed athletes starting point and ball point trunk anteversion angle was greater than the true swing(p<0.05), amplitude angle changes on the rod and the lower rod were no significant differences in trunk; the shoulder hip angle under the maximum value was greater than the vertex(p<0.01), under the shoulder hip angle was less than the true swing angular velocity Omega 1(p<0.01), less than 2. True swing(p<0.05); high speed athletes under the maximum head speed greater than rod ball head speed, high speed athletes did not make full use of the triceps muscle of the elbow extension and wrist flexion of the flexor carpi ulnaris; low speed athletes shoulder hip angle eccentric contraction time T1 was less than the true swing(p<0.05), concentric contraction time T2 shoulder hip angle was greater than the true swing(p<0.05), under the rod head speed less than the maximum ball head speed. In the process of the lower rod, only the wrist flexion was used, and the extension of the elbow joint was neglected.(3) Fake ball practice characteristics of the speed control rod head:The role of high speed athletes starting point and the contact point of the front torso angle was larger than true swing(p< 0.05) and trunk anteversion pole change amplitude and rod under variation of no difference; during the downswing biggest club head speed was greater than the ball club head speed; do not make full use of extension of the elbow joint, humeral head muscle and the wrist flexion and ulnar flexor muscle of wrist to achieve accelerated the blows of the extremities; low speed players without the ball exercises when fixing and practice with true swing different, in under the bar in the process of the use of only the wrist flexion, while ignoring elbow extension.(4) Fake ball practice hitting accuracy control characteristics:For high speed athletes, the rod surface toward the change range before hitting was less than the true swing(p< 0.05); low speed athletes lateral trunk flexion angle less than true swing(p< 0.05), hitting front rod surface toward the change range was less than the true swing(p< 0.05).(5) Lower back muscle strain injury protection characteristics:For high speed players, without the ball hitting point of head rotation was significantly smaller than the true swing(p<0.01), with the essential stage of head rotation rate was less than the true swing(p<0.01), the end of the torsion angle was smaller than the real head swing(p<0.01); with the shoulder hip angle swing phase angular velocity Omega F was less than the true swing and the difference was very significant(p<0.01); without the ball practice and true swing were the centrifugal contraction against the left circumflex trunk; match-fixing exercises with essential stage head rotation rate was less than the true swing(p<0.01), the end angle was smaller than the true swing reverse nod(p<0.01); in the swing process against the trunk muscles with non left circumflex contraction passively stretched.For low speed players, without the ball batting practice point head rotation angle was less than the true swing(p<0.01); end point less than true swing(p< 0.01); with the wave amplitude was smaller than the true swing(p< 0.01); low speed athletes end points, without the ball exercises of shoulder and hip angle less than true swing, and the difference was significant(p<0.05); without the ball exercises of with essential stage right latissimus dorsi inactivation, alone on the left side of the abdominal external oblique muscle against the right side of the abdominal oblique and left dorsal latissimus dorsi complete upper torso deceleration and braking. Conclusions:(1) Ball/ no ball affected athletes’ head rotation:Head rotation did not change when doing fake/no ball practice of high speed athletes; But low speed players’ head rotation changed at beginning and the impact point, when there is no ball.(2) Ball/ no ball influenced the ball player action program:Fixing practice did not affect the action program, without the ball exercises of high speed athletes in action program invariant; action procedures of low speed athletes with essential changes in relative time.(3) Athletes of different levels of ball club had different ways to control speed:High speed athletes through on reflective state, the rate of change of the shoulder and hip angle, trunk anteversion angle, elbow flexion and ball joint anterior fixed five ways of regulation according to context changes control ball club head speed; low speed athletes through the position of the center of pressure, elbow flexion and ball joint anterior fixed three ways of regulation according to context changes to control the ball club head speed.(4) Athletes of different levels had different ways to control hitting accuracy:High speed athletes by controlling the hitting arm rotation, and joint fixed control shot accuracy; low speed athletes through control before hitting the lateral bending of the trunk, the joint angles and the fixed control hitting accuracy.(5) Athletes of different levels had different ways to protect from lower back straininjury:Club head speed of high speed athletes in the most prone to injury without the ball exercises first to control the ball, and the reflective state control muscle tension, with the essential process of back muscles in the trunk of the upper part of the brake needs a smaller force, and the centrifugal contraction, in order to reduce the risk of muscle strain without the ball; low speed players without the ball exercises, the less active muscle on the brake of the upper trunk, a short period of time, elongation, easily exceed the tolerance limits of the muscle resulting in acute injury. |
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