make use of its constructs. So, we can say that all body movements are unified to form fully integrated performances or motor behaviors (5: 5).

Transcription

1 Effects of Specific Exercises, in the Light of Biomechanical Analysis of some Technical Phases, on Throwing Distance among Female Shot Putters Dr. Wahid Sobhy Abd ElGhaffar Dr. Naglaa Mohamed AlSaudi Abstract: The current research aims at improving the throwing distance of female shot putters through designing a specific training program based on biomechanical variables and identifying its effects on the digital record of shot put. The researchers used the experimental approach (onegroup design) with pre and postmeasurements and the descriptive approach (case analysis). For biomechanical analysis, Fadia Saad Ibrahim, an international athlete who is Egypt s champion, All Arabs Champion and holder of African third rank, was chosen for analyzing her performance. The researchers chose (8) shot putters from Kafr AlShaikh Sportive Club. Only the best two trials of each athlete were analyzed and therefore (6) trials were analyzed. Results indicated that the specific training program based on biomechanical analysis has led to statistically significant differences between pre and postmeasurements in favor of postmeasurements on the following variables: Projection angle and, altitude of projection point, duration of pushing phase, digital level. Beginning of glide phase: angles of knee and hip joints, of thigh, shank, trunk and CG. momentum of shank and trunk. End of glide and beginning of push: hip and knee joints angles, knee angular, resultant of upper arm, thigh, shank, foot, trunk and CG. of trunk and CG, of shank and trunk, CG momentum. End of pushing: elbow, hip and knee angles. knee angular. of forearm, upper arm, thigh, shank, trunk and CG. of forearm, thigh and trunk, resultant of thigh and trunk. Momentum of forearm, thigh, trunk and CG. Key words: Biomechanical Analysis Specific Exercises Background: Biomechanics is the field of studying and analyzing motor performance in the light of the factors affecting it directly or indirectly to reach the best solutions for motor problems with the aim of improving athletic performance (: 5) Alaa ElDin, G. (989) indicated that mastering and improving athletic performance is dependent on the correctness of partial details of the movement and how they join together. During performance, the athlete directs these factors and controls them. The important thing is not only how to construct this system of movements during skills performance but also how to control and direct it to

2 make use of its constructs. So, we can say that all body movements are unified to form fully integrated performances or motor behaviors (5: 5). Abd ElDaim et al (993) indicated that specific training means that coaches concentrate on strengthening the agonists in a specific activity. This means that we should have full knowledge with functions of agonists and to choose the best training method that looks like real performance (3: 83) Specific training is characterized by its specific power to improve physical abilities and skills performance. Considering quantity, quality and time, it is highly specific according to its momentarily use for working muscles. This is very crucial for successful use of neuromuscular use in performance (5: 96) Shot put is a major field event as body movement and its ability to achieve are closely related so that distance represents individual ability of motor achievement. This needs to link all motor paths of body segments together during performance to use muscular work and to produce massive pushing consistent with the motor path without any disturbance of the desired trajectory which is the sum of various resources and may affect the resultant of the agonists (4: 89, 6) Review of literature indicated a trend of studies dealing with this issue. Ghoraba, M. (008) (3) identified the effects of a specific training program in the light of quantitative and qualitative analyses on improving the arm and neck movements in wrestlers. Abd ElHaleem, M. & Salama, A. (008) (8) identified the effects of a specific training program in the light of biomechanical analysis of the takeoff phase in long jump on improving the digital record. Bion et al (008) (7) performed a biomechanical analysis of the shot put male athletes during the World Athletics Championship 007. Sobhy, W. (0) (4) performed a comparative study for some biomechanical variables and EMG of shot putters using crawl and circle techniques. Rashad, A. & Sobhy, W. (00) (0) identified the effects of a specific training program, in the light of kinematic analysis of the throwing arm, on javelin throwing distance, among disabled athletes Class F58. Shot put is a major event that is affected greatly with the advance of kinematic analysis devices as analyzing champions performances identified the optimum technical performance methods for improving specific training programs. Although this is not a new trend, it is now very important to assure the importance of biomechanical analysis in shot put as world records of performance are now amazing due to the high degree of mastery in fulfilling motor tasks. This is due to modern advances in teaching and training these skills. We still need more effort to maintain high achievements of athletes and to produce new champions using modern advances in analyzing world champions and using results in devising specific training programs. Coaches do not use biomechanical analysis of performance in planning specific training programs. According to the researchers knowledge, there is a lack in specific training programs based on biomechanical analysis of technical

3 phases of shot put performance. This led the researchers to design a specific training program based on biomechanical variables and identifying its effects on the digital record of shot put. Aim: The current research aims at improving the throwing distance of female shot putters through:. Identifying biomechanical indicators of some technical phases of shot put through review of literature and analyzing the performance of Egypt s and All Arabs champion in shot put.. Recommending specific training exercises in the light of biomechanical indicators of some technical phases of shot put 3. Identifying the effects of the recommended exercises on improving some biomechanical indicators and the throwing distance of shot put Hypotheses:. There are statistically significant differences between pre and postmeasurements of some biomechanical indicators of shot.. There are statistically significant differences between pre and postmeasurements of the digital record of shot put. Methods: Approach: The researchers used the experimental approach (onegroup design) with pre and postmeasurements and the descriptive approach (case analysis) Participants: For biomechanical analysis, Fadia Saad Ibrahim, an international athlete who is Egypt s champion, All Arabs Champion and holder of African third rank, was chosen for analyzing her performance. The researchers chose (8) shot putters from Kafr AlShaikh Sportive Club. Only the best two trials of each athlete were analyzed and therefore (6) trials were analyzed. The researchers homogenized participants for weight, age, training period, digital record and some physical variables and found out that squewness values were between (±3). Table () shows homogeneity of participants. Table (): Participants homogeneity on all research variables Variable Measurement Median Mean SD Squewness Weight Kg Overall length Cm Arm length Cm The length of the Cm lower limb

4 Age Month Training period Kg Grip strength Kg Leg strength Kg Back strength Kg Wide jump Cm Sit up No Sit up with bent knees No Data collection tools: The researchers used biomechanical analysis devices, motion capture devices. Shot puts measurements, measurements of some variables and physical tests. Pilot study: The researchers performed the pilot study on a pilot sample (n=3) from the same research community and outside the main sample to validate the suitability of tools, recommended program and test procedures. This pilot study was performed on 704. Main study procedures: Motion capture and analysis: The researchers initiated motion capture procedures in the courts of Faculty of Physical Education Kafr AlShaikh University according to procedures of motor analysis. Athletes were prepared and joints were marked. Motor analysis device (Dmas7) was used with highspeed cameras (0 f/sec) fixed on tripods on the direction of the pushing arm. Cameras were fixed to clearly capture the athlete s movement during time points under investigation (crawl pushing). Camera lens was.4m from earth and 9m from athlete. The best two trials for each athlete were analyzed. Identifying biomechanical variables: Biomechanical variables were identified through review of literature (7) (4) and motor analysis of the Egyptian champion s performance. Premeasurements: Premeasurements of the biomechanical variables, physical variables and digital records of participants were taken from 5704 to The Recommended Specific Training Program: The specific training program (annex ) was designed using some exercises (annex ) formulated according to review of related literature and biomechanical analysis of the performance of Egypt's and All Arabs' Champion in shot pot. The performance of this champion was chosen for analysis to identify the fine details of performance. The values of biomechanical variables revealed by this analysis were used as indicators of ideal performance (annex 3). 4

5 These values were used in designing the specific training program as exercises concentrated these variables at the same direction of movement. Basics of designing the specific training program: Through review of related literature and educational and training programs for shot pot, the researchers concluded the following: Biomechanical analysis of the distinguished athlete and the rest of participants to identify limitations of participants' performance compared to ideal performance. Exercises were designed according to the model's performance with special consideration of and required, body joints' angles and release point altitude during performance. Exercises were progressive from easy to difficult using partialholistic method Considering principles of flexibility and continuity in performance Using suitable training equipment required for exercises Establishing correct training load variables (intensity volume density) (9: ) (4: ) (0) Variable Projection angle Main Application: The recommended program was applied from 704 to 6904.The recommended program was designed according to review of literature and biomechanical analysis of the Egyptian champion. The program included (8) week of training (4 units per week) as each unit was (90) minutes. (6: 35) (5: 8) (6: 4) Postmeasurements: Following the same protocol of premeasurements, postmeasurements of all variables under investigation were taken on Raw data was prepared for statistical treatments. Statistical treatment: The researchers used SPSS software to calculate the following: median mean SD squewness (t) test improvement percentage (%). Results: Table (): Difference significance, (t) values and improvement percentage between pre and postmeasurements of some kinematic variables of participants Measurement Premeasurement Postmeasurement Means difference (t) (%) Mean SD± Mean SD± Mean SD± Deg *

6 Projection Projection altitude Duration of crawl Duration of pushing Digital level M/s * (mm) * (sec) (sec) * 55 (m) *. * Significance on P 05 =.3 Table (3): Difference significance, (t) values and improvement percentage between pre and postmeasurements of some angular kinematic variables of participants (On beginning of crawl) Variable Measurement Premeasurement Postmeasurement Means difference (t) (%) Mean SD± Mean SD± Mean SD± Elbow angle deg Elbow angular rad / sec Elbow angular rad / sec hip angle deg * 434 hip angular rad / sec hip angular rad / sec Knee angle deg * 3.49 Knee angular Knee angular rad / sec rad / sec * Significance on P 05 =.3 6

7 Table (4): Difference significance, (t) values and improvement percentage between pre and postmeasurements of some angular kinematic variables of participants (At the end the crawl and the beginning and pushing) Knee angular Knee angular ariable lbow ngle lbow ngular elocity lbow ngular cceleration rad / sec * rad / sec * Significance on P 05 =.3 Table (5): Difference significance, (t) values and improvement percentage between pre and postmeasurements of some angular kinematic variables of participants (On Projection) Measurement Variable Measurement Premeasurement Postmeasurement Means difference (t) (%) Mean SD± Mean SD± Mean SD± Elbow angle deg Elbow angular rad / sec Elbow angular rad / sec hip angle deg * hip angular rad / sec hip angular rad / sec Knee angle deg * Premeasurement Postmeasurement Means difference (t) (%) Mean SD± Mean SD± Mean SD± deg * rad / sec rad / sec

8 ip angle deg * ip angular rad / sec elocity ip angular rad / sec cceleration nee angle deg * nee ngular rad / sec * elocity nee ngular cceleration rad / sec * Significance on P 05 =.3 Table (6): Difference significance, (t) values and improvement percentage between pre and postmeasurements of some biomechanical variables of participants (At the beginning of crawl) Variable Measurement Premeasurement Postmeasurement Means difference (t) (%) Mean SD± Mean SD± Mean SD± * [mm/s] [mm/ ] high G [N] Momentum [kg m/s] ank [mm/s] * 3.0 8

9 G [mm/ ] [N] Momentum [kg m/s] * [mm/s] [mm/ ] oot G [N] Momentum [kg m/s] * [mm/s] [mm/ ] runk G [N] Momentum [kg m/s] * * [mm/s] [mm/ ] ody G [N] Momentum [kg m/s] * Significance on P 05 =.3 Fore arm Table (7): Difference significance, (t) values and improvement percentage between pre and postmeasurements of some biomechanical variables of participants (At the end the crawl and the beginning of pushing) Variable Measure ment [mm/s] Premeasurem ent Mea SD± n Postmeasurem ent Me SD± an Means differenc e Me SD an.8 ± (t).86 (% ) 5 9

10 0 CG 75 [mm/ ] [N] Momentum [kg m/s] Upp er arm CG [mm/s] * [mm/ ] [N] Momentum [kg m/s] Thig h CG [mm/s] * [mm/ ] [N] Momentum [kg m/s] shan k CG [mm/s] * [mm/ ] [N] * Momentum [kg m/s]

11 Foot CG Trun k CG Bod y CG Momentum Momentum Momentum [mm/s] [mm/ ] [N] [kg m/s] [mm/s] [mm/ ] [N] [kg m/s] [mm/s] [mm/ ] [N] [kg m/s] * Significance on P 05 = * *.48 8 *.8 6 * *.6 * * Table (8): Difference significance, (t) values and improvement percentage between pre and postmeasurements of some biomechanical variables of participants (On Projection) Variable Measurement Pre Post Means (t) (%

12 arm er CG gh nk ot nk measurement measurement difference Mean SD± Mean SD± Mean SD± * [mm/s] * [mm/ ] [N] Momentum [kg m/s] * * [mm/s] [mm/ ] [N] Momentum [kg m/s] * [mm/s] * [mm/ ] * [N] Momentum [kg m/s] * * [mm/s] [mm/ ] [N] Momentum [kg m/s] [mm/s] [mm/ ] [N] Momentum [kg m/s] * [mm/s] [mm/ ] *

13 dy * [N] * Momentum [kg m/s] * [mm/s] [mm/ ] [N] * Momentum [kg m/s] * Significance on P 05 =.3 6 Time Figure (): Velocity Dynamics for body Center of Gravity (pretest posttest Model) for shot put Time Figure (): Acceleration Dynamics for body Center of Gravity (pretest posttest Model) for shot put R Acceleration Time Momentum 3

14 Figure (3): momentum Dynamics for body Center of Gravity (pretest posttest Model) for shot put Time Figure (4): Velocity Dynamics for Forearm's Center of Gravity of the pushing Arm during pushing stage (pretest posttest Model) Time Figure (5): Velocity Dynamics of Upper Arm's Center of Gravity of the pushing Arm during pushing stage (pretest posttest Model) Figure (6): Time of pushing stage (pretest posttest Model) for shot put 4

15 Figure (7): Launch Point Altitude (pretest posttest Model) Discussion: Table () and Figures (, 6) indicates improvements between pre and postmeasurements in favor of postmeasurements on the following variables: projection angle and projection altitude duration of pushing digital level. The researchers think that this is due to the effects of the specific training program. This is consistent with Tawfik, F. (000) and Zaher, A. (00) who indicated that exercises performed on the same motor path help improving projection angle and altitude, just like throwing between two ropes held on a suitable altitude in front of the athlete and throwing in hoops (: 7688) (: 588). This is also consistent with AlSokary, K. & Hassan, S. (997) who indicated that using various and light tools for throwing in the same motor path improve technique and increase throwing arm which in turn improves projection and the digital record in shot put (8: 6367). Rashad, A. & Sobhy, W. (00) indicated that specific training in javelin throwing improves projection and angle, projection altitude and the digital record (0: 3 330). Table (3) indicates statistically significant differences during beginning of crawl between pre and postmeasurement in favor of postmeasurements on pelvis and knee angles. This is due to the effects of the specific exercises as they help athletes to maintain trunk and knee bent during crawl. This is consistent with Bastawisy, B. (997) who indicated that performance of shot put is affected by low crawl without losing (9: 43744). Table (4) indicates statistically significant differences during end of crawl and beginning of pushing between pre and postmeasurement in favor of postmeasurements on pelvis and knee angles and knee angular. This is due to the effects of the specific exercises as they help athletes to maintain trunk and knee bent during crawl as this prepared the athlete to push from a wider range of motion and increased and. This is consistent with Bastawisy, B. (997) who indicated that maintaining trunk and knee bent are very important during crawl. The optimum knee angle at the end of crawl and beginning of push is (0 ). Knee angle at premeasurement was (40 ) and became (9 ) in 5

16 postmeasurement. This indicated the improvement of performance and the effectiveness of the recommended program (9: 43744). Bending knee and trunk and maintaining that during crawl help athletes to compensate body inertia. When centers of gravity of body parts come closer to body center of gravity this increases angular (: 774). Table (5) indicates statistically significant differences during projection between pre and postmeasurement in favor of postmeasurements on elbow, pelvis and knee angles and knee angular. This is because the specific training program includes exercises that improve the full range of motion for knee, pelvis and elbow during projection with optimum use of ground reaction. This is consistent with Bastawisy, B. (997) (9: 445). Table (6) indicates statistically significant differences during beginning of crawl between pre and postmeasurement in favor of postmeasurements on the following variables: resultant of thigh, trunk and body CG (Fig. ) momentum of leg and trunk. This is because the recommended program includes exercises that improve strength and at the same motor path. This is consistent with Bastawisy, B. (997) and Darwish & Abd ElHafez (999) who indicated the importance of exerting and at the desired direction and technique can be improved through accelerating performance without losing between stages until projection. (9: ) (: 4, 46, 89). Momentum transfer from limps to trunk and from trunk to the throwing arm is very important for performance as momentum = segment mass x segment. This is consistent with Abd ElMoneam, S. et al (99), Hosam El Din, T. (994) and Berequa & AlSokary (00) (: 56) (5: 6) (0: 76). Table (7) and Figures (,, 3) indicates statistically significant differences during end of crawl and beginning of pushing between pre and postmeasurement in favor of postmeasurements on the following variables: resultant of upper arm, thigh, leg, foot, trunk and body CG (Fig. ) resultant of trunk and body CG resultant of leg and trunk momentum of body CG. This may be due to the program exercises that improved the neuromuscular function and increased resultant and for most body parts, in addition to using additional pushes (momentum transfer). This is consistent with Bastawisy, B. (997) and Darwish & Abd ElHafez (999) who indicated the importance of exerting and at the desired direction. (9: ) (: 4, 43, 46, 89). Table (8) indicates statistically significant differences during projection between pre and postmeasurement in favor of postmeasurements on the following variables: resultant of forearm, upper arm (Figures. 4, 5), thigh, leg, trunk and body CG (Fig. ) resultant of forearm, thigh and trunk resultant of thigh and trunk momentum of forearm, thigh, trunk and body CG. This is because the recommended program includes exercises that improve strength and at the same motor path and this leads all body parts to move faster. Velocity and have a directly 6

17 proportional relation. As resultant improves for most body parts, resultant at forearm, thigh and trunk improve. Force = mass x. Momentum = mass x. This led to significant improvement of resultant at thigh and trunk, and momentum at forearm, thigh, trunk and body CG. (: 46) (: 5456, 995) (5: 98) (: 76, 89, 03). Conclusions: In the light of these results, the researchers concluded the following:. Using the recommended specific training program based on biomechanical analysis led to statistically significant improvements between pre and postmeasurements in favor of postmeasurements on the following variables: projection angle and projection altitude duration of pushing digital level.. Using the recommended specific training program based on biomechanical analysis led to statistically significant differences at the beginning of crawl between pre and postmeasurement in favor of postmeasurements on hip and knee angles, of thigh, shank, trunk and body CG. momentum of shank and trunk. 3. Using the recommended specific training program based on biomechanical analysis led to statistically significant differences at the end of crawl and beginning of pushing between pre and postmeasurement in favor of postmeasurements on: hip and knee angles and knee angular, of upper arm, thigh, shank, foot, trunk and body CG. of trunk and body CG, resultant of shank and trunk, momentum of body CG. 4. Using the recommended specific training program based on biomechanical analysis led to statistically significant differences on Projection between pre and postmeasurement in favor of postmeasurements on the following variables: elbow, hip and knee angles. knee angular. of forearm, upper arm, thigh, shank, trunk and body CG. of forearm, thigh and trunk, resultant of thigh and trunk. Momentum of forearm, thigh, trunk and body CG. Recommendations: In the light of these conclusions, the researchers recommend the following: Using the recommended specific training program in training javelin throwing, discus and other events 7

18 Using biomechanical indicators of crawl and pushing stages and the content of the recommended specific training program to plan training programs for shot put References: Abd AlMuneam, Sawsan et al. (99): Biomechanics od Sport: Biodynamic (P). Alexandria Egypt (in Arabic) Abd ElBaseer, A. (998): Biomechanics: Integration of Theory and Practice 3 rd ED. Markaz AlKetab Press Cairo Egypt (in Arabic) 3 Abd ElDaiem, Mohamed et al. (993): Physical Preparation Program and Weight Training. AlAhram Press Cairo Egypt (in Arabic) 4 Abd ElGhaffar, Wahid S. (0): A comparative study of some biomechanical variables and EMG in shot put with two methods (crawl circle). The International Conference of Sports Creativity Faculty of Physical Education Kafr AlShaikh University Egypt (in Arabic) 5 Alla ElDin, Gamal (989): Movement system: systems of direction and control. Journal of Theories and Applications, No. 6 Faculty of Physical Education for Men Alexandria University Egypt (in Arabic 6 Allawy, Mohamed Hassan (994): Sports Training, th ED. Dar Al Maaref Cairo Egypt (in Arabic) 7 AlSharnoby, S. & Haridy, A. (998): Track and Field Events: Track medium distances crosscountry shot put high jump. AlEshaa Al Fania Press, Cairo Egypt (in Arabic) 8 AlSokary, K. & Hassan, S. (997): Guide for Teaching and Training Throwing Events. Dar AlMaaref Cairo Egypt (in Arabic) 9 Bastawisy, Bastawisy A. (997): Track and Field Events: Teaching and training technique. Dar AlFikr AlAraby Cairo Egypt (in Arabic) 0 Berequa, M. & AlSokary, K. (00): Basics of biomechanics in sport, Part one. Munshaat AlMaaref Alexandria Egypt (in Arabic) Berequa, Mohamed Gaber (00): Biomechanics. AlHadara Press Alexandria Egypt (in Arabic). Darwish, Z. & Abd ElHafez, A. (999): Encyclopedia of Athletics: Throwing. Munshaat AlMaaref Alexandria Egypt (in Arabic) 3 Ghoraba, Moj=hamed Saad (008): Effects of a specific training program in the light of quantitative and qualitative analyses on improving arm and neck movements in wrestlers. PhD thesis, Faculty of Physical Education Tanta University Egypt (in Arabic) 4 Hassan, S. AlKhadem, A. % Darwish, Z. (983): Analysis of Track and Field Events. Dar AlMaaref Cairo Egypt (in Arabic) 5 Husam ElDin, Talha (994): Motor and Functional Principles of Sports Training. Dar AlFikr AlAraby Cairo Egypt (in Arabic) 6 Ismail, Mohamed A. (998): Strength Training and Weight Training Programs. Munshaat AlMaaref Alexandria Egypt (in Arabic) 7 Kigo Oia Bion et al (008): Biomechanical analysis of male shot putters during 007 world championship. Journal of the International Federation of 8

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