| Objective: Based on the biomechanical data obtained from the experiment,this paper studies the technical characteristics of the block movement of male volleyball players in place,and compares and analyzes the differences of the technical movement between different grades,so as to discuss the technical characteristics of the movement of athletes of different grades,in order to fundamentally understand the action of block jump in place,so as to improve the athletes’ technical action,for volleyball special training to provide scientific and effective theoretical basis.Methods: By using Qualisys motion capture system and Bertec 3D dynamometer platform,26 male volleyball players from Inner Mongolia Normal University were tested on the technique of block in place jump.All the athletes were divided into two groups according to their sports grades,namely the first group and the second group,of which 13 were the first and 13 were the second.From the technical action time,joint angle,joint speed,pressure center and mechanical characteristics of the lower limb technical action of the block in place to analyze,the obtained data were expressed as mean±standard deviation（X±SD）,and independent sample t test was conducted between different groups to analyze the similarities and differences of the characteristics of the movement among athletes of different grades,significant level（P<0.05）and very significant level（P<0.01）.Results:1)The time of the first group was shorter than that of the second group in the stage of take-off and extension,take-off and landing buffer,and the time of the second group was longer in the stage of take-off and landing buffer;in terms of total time,the time of block technique in place jump in group one was shorter than that in group two,and there was a significant difference between the two groups（P < 0.05）.As for the proportion of the total time of each stage in the technical movement,the proportion of the take-off buffer stage and the airborne stage in the first group was larger than that in the second group,and the take-off kick stage and the landing buffer stage were smaller than that in the second group.2)In the take-off buffer stage,the hip and knee angles of grade one group were smaller than that of grade two group,while the ankle angle was larger than that of grade the second group.The knee angles of different grade groups showed significant differences（P < 0.05）;in terms of the range of joint changes,the range of hip and knee changes in grade one group was larger than that in grade two group,while the range of ankle changes was smaller than that in grade two group.There were significant differences in the range of knee changes in different grade groups（P < 0.05）.In terms of kinetics,the movement differences of transverse force,longitudinal force,vertical force and COP in X and Y axes of the first group were smaller than those of the second group,the longitudinal force showed significant difference（P < 0.05）.3)In the the take-off kick stage,the index values of hip,knee and ankle joint angles and joint flexion and extension range in the first group were greater than those in the second group,and there was a significant difference in ankle joint angle（P < 0.05）,there were significant differences in the range of knee flexion and extension（P < 0.05）;in terms of the peak value of angular velocity,the values of the three joints in grade one group were higher than those in grade two group,and the knee joint values showed highly significant differences（P < 0.01）.In terms of kinetics,the lateral and vertical forces of the first group were larger than those of the second group,while the longitudinal forces were smaller than those of the second group,both COPx and COPy values were lower than those of secondary group.4)In the airborne stage,the hip and ankle angles of the first group were larger than those of the second group,and the knee joints were smaller than those of the second group.When the body was at the highest point,the hip joint angle of grade the first group was significantly smaller than that of grade one group,and there was significant difference among different grade groups（P < 0.05）.5)In the landing buffer stage,the three joint angles of lower limbs in grade one group were larger than that in grade two group,and there was significant difference in hip joint（P < 0.05）;the range of flexion and extension of the three joints of lower limbs in the first group was smaller than that in the second group,and the difference in knee joints was significant（P <0.05）;in terms of the peak values of angular velocity,the peak values of hip,knee and ankle joints in grade one group were higher than those in grade two group,and there was a significant difference in knee joint indexes（P < 0.05）.In terms of kinetics,except for the longitudinal force and vertical force,the first group was smaller than the second group.Conclusion: 1)The movement time of block technique in the first group was faster than that in the second group.The proportion of time in different stages of different grade groups to the total time was as followed: the airborne stage > the take-off buffer stage > the take-off kick stage > the landing buffer stage.2)In the take-off buffer stage,the buffer height and amplitude of the first level athletes were more suitable for blocking movement,and the body center of gravity of the first level athletes was relatively stable;in both groups,the knee joint was the main cushioning joint,followed by the hip and ankle joint.3)In the take-off kick stage,the athletes in group one were more active and full than those in group two.In the order of joint force,both groups formed a motion chain with small joint driving large joint.At the end of the stage,the two feet in the first group were more balanced,and the kinetic energy gained in the air was larger.4)In the airborne stage,when the body was at its highest point,the hip joint of the first group was smaller than that of the second group,and the hip joint angle changed more than that of the second group,forming a blocking form centered on the hip joint.5)In the landing buffer stage,the range of flexion and extension of the lower limbs of male volleyball players was in descending order: ankle joint >knee joint > hip joint.The range of lower limb joint angle flexion and extension of grade one athletes was smaller than that of grade two athletes.For the rapid input into the next part of the preparation,at the same time,the first group of gravity recovery fast,stable landing center of gravity. |
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