Badminton is one of the most popular racket sports in the world. In Badminton, there are various skills- long service, short service, drop shot, overhead smash forehand smash, backhand smash etc. The most commonly used stroke is the Short service. It is the best skill of execution that determines to surmount the other player. Badminton is foremost racket sports; however, there is still a lack of scientific research and Biomechanical research done on this sport as compared to other sports such as Swimming, Soccer and Athlatics.
There are relatively little scientific investigations on the execution of badminton Short service. It will be beneficial for the Sports Scientists, Badminton coaches and players to study the applied mechanics and their effect involved in the Short service. This would add knowledge and information which will be enhanced the performance of Athletic in Badminton sports.
Gowitzke & Waddell (1979) analyzed forehand and backhand smash strokes, representative of the most powerful overhead striking motions in badminton, They concluded that medial rotation of the humerus at the shoulder joint and pronation of the forearm at the radio-ulnar joints were the principal contributing movements for the forehand smash.The previous studies focused on the description of forehand smash such as Poole, 1970; Adrian, 1971 and Gowitzke, 1979. Tang, et al. (1995) and Tsai and Huang (1998) were analyzing the movement using Direct Linear Transformation (DLT) on images recorded by high speed cameras. These studies concluded that pronation of the radio-ulna joint were the most significant with the largest range and the shortest time among the three rotations of the upper limb. Tsai and Huang (1998) also compared the performance of the smash between elite and collegiate players.
In badminton strokes, many joint actions in three planes are involved in the striking motion, so that two-dimensional procedures are insufficient for analyzing the stroke motion of badminton. Relatively small numbers of biomechanical studies have been completed on kinematic parameters of badminton strokes. Quantitative studies with vediographic procedures have been even more limited. The purpose of this investigation was to determine the changes of joint angles of the upper body during the performed of the drop shot and the cut shot in badminton.
Six male North-Zone inter-varsity badminton players were used as subjects. Their age, height, and body mass are 22±1.78 yrs, 1.66±0.05 m, and 62.16±7.11 kg, respectively (mean ± SD). The each subject was instructed to perform the drop shot and the cut shot. All the selected players have readily agreed and volunteered to act as subject for the study during North-Zone intervarsity 2009-2010 at A.M.U Aligarh.
The video graphic technique was further organized in to two sections. These are:
Video Graphic Equipments and Location
Subject and Trail Identification
Vediographic Equipments and Location
The subject’s drop shot and cut shot motion were recorded using Legaria Canon SF-10, 8.1 Mp video camera in a field setting operating at a nominal frame rate of 50 Hz and with a shutter speed of 1/2000 s and at 60fps camera were set up 10 m away from the subject in a field setting. The camera was set-up on a rigid tripod and secured to the floor in the location.
The camera was positioned perpendicular to the sagittal plane and parallel to the mediolateral axis (camera optical axes perpendicular on the sigittal plane) as their drop and cut shot arm giving approximately a 90o between their respective optical axes. The camera was also elevated to 95 cms and tilted down in order to get the image of the subject as large as possible while that all points of interested remained totally within
(ii) Subject and trail Identifications
To identification the subject in the video graph, each subject was given with a numbers. as to distinguish in the data recorded. For identification purposes of a best performance, the trails were viewed on the computer system and exarter on the subject (thrower) demarketed the trail for the data acquisition.
After video recording sessions were over, the video recording was loaded in to the researcher’s personal computer (PC) for trail identification. The identified trails were played with the help of Silicon Coach Pro-7 software to make separate clips of each badminton player. The separate clips were then opened on to the Silicon Coach Pro-7 software. The software has provision to analyze the angles, displacement, time, speed, acceleration and number of frames as in the feature. From these digitized data, three-dimensional coordinates of the landmarks on the subject’s body and on the racket were reconstructed by means of the Direct Linear Transformation (DLT) method (Abdel-Aziz and Karara, 1971).
The general purpose of this study was to determine if a common inter segmental coordinative pattern existed between over head throw, with the hopes of being able to make every throw look the same. Both qualitative and quantitative measures were used for data analysis.
Table: 1 kinematics differences between drop shop and cut shot of badminton players.
D= Drop shot C = Cut shot S.D= Standard Deviation
Tab t.0.05 (10) =2.22
*Significance difference at 0.05 levels.
Fig.1: Graphical representation of kinematics of drop and cut shot performance of badminton players.
The analysis of data table-1 shows that there is a no significant difference between drop shot and cut shot badminton player as shoulder angle obtain t’ ratio is less than the required t value of 2.101.whearas significance differences between drop shot and cut shot badminton player as wrist, elbow angle and shuttle velocity between drop and cut shot of badminton players.
Table: 2 Maximum angular velocities of joints of striking arm for the drop shot and cut shot prior to impact (deg/sec).
Fig-2: Graphical representation of angular velocities of joints (deg/sec) of badminton players..
Result:-2 of Descriptive analysis revealed that the peak values (mean ± SD) of the angular velocity of each joint action. The performance of elbow extention/flexion were approximately twice those for wrist flexion and shoulder adduction/ abduction, shoulder lateral/medial rotation angular velocity were approximately same in drop shot and cut shot prior to impact. The angular velocity also higher in drop shot as compare to cut shot at all respective joints.
The study shows the changes of angles (upper) and angular velocities (lower) of the joints of the striking arm for the drop shot motion of subject. Table: 1 shows that wrist, shoulder angle and shuttle velocity in drop shot were more than cut shot and the ranges of the changes of the joint angles were more than 90 degrees for abduction / adduction at the shoulder, and extension / flexion at the elbow. Highest peak values of the angular velocities were observed in extension of the elbow. The patterns of the changes of the angles and the angular velocities were similar for all subjects. Table 1 shows the peak values (mean ± SD) of the angular velocity of each joint action. Table shows the changes of the angles and angular velocities of extension / flexion of the elbow, shot and the cut shot of subject A. Peak values of the angular velocities of these joint actions were larger in the cut shot motion than in the drop shot motion. Flexion of wrist just before impact was the highest and was a characteristic action for the cut shot. The range of motion and peak value of the angular velocity of ulnar-flexion for the cut shot were approximately twice those for the drop shot.
Changes of angles and angular velocities of joints of the striking arm were determined during the performance of the drop shot and the cut shot in badminton using of two-dimensional analysis. In the drop shot, highest peak values of angular velocity were observed in pronation of the radio-ulnar joints, extension of the elbow joint, and ulnar flexion of the wrist joint. Compared to actions in the drop shot, ulnar flexion of the wrist joint stood out in the cut shot motion. The changes of angles and angular velocities of the joints showed different patterns dependent on the strokes, and the results suggested the effectiveness of two-dimensional film analysis technique in the investigation of badminton strokes.
The authors would like to acknowledge the cooperation of UGC-SAP (DRS-I) Programme, Department of Physical Health and Sports Education, Aligarh Muslim University, Aligarh