The Impact of Force Production on Initial Acceleration Interacting with Block Start Obliquities

ABSTRACT


INTRODUCTION
The athlete's reaction to the gun and initial application of force against the starting blocks majorly impacts overall sprinting performance, particularly in races of 100m or less (Nagahara, 2020).In the focus is on creating horizontal velocity and putting the athlete's body in position for drive phase. At the set command the athlete raises hips and leans as far forward without moving. With the sound of the gum trunk straightens and lifts as both feet press against the blocks. (Figueiredo, 2021) The hands lift from the ground together then swing alternately. The push of the rear leg should be hard and short, so the leg moves forward rapidly, while the push of the front leg is little less hard but longer (Harland MJ. Steele JR, 1997).

LITERATURE REVIEW
This study aimed to evaluate the initial loading position in a foot block paddle with various notches for block clearance and the accuracy of reaction time friction force in order to calculate the kinetic functions that occur when the centre of mass moves. The block start involves several different considerations. Coaches who are experts assert that the instruction "on your marks" signals the start of the real block start (Jones R, 2009). Numerous researchers in the scientific community have been looking into the question of which of the process's many elements are most important for a certain stage of the race. Some of them have concentrated their efforts on doing research on the lower extremities, specifically in terms of acceleration, feet-to-block lengths, response times, and full-speed 20-meter sprints (Haugen T. A., 2019). In order to achieve a combination of high force power and high maximum force, Harland and Steele established that the sprinter should position his or her back knee in the "set" position between 90 and 130 ºof flexion. Additionally, the sprinter should keep their hips reasonably high. Because of this setting, it is possible to start at a low angle (between 40º and 45 º), which helps to reduce the likelihood of horizontal braking forces (Schrödter, 2016). The use of starting blocks in sprint competitions helps to decrease the impact of the athlete's feet hitting the ground. This research will be carried out with the goal of determining how a sprinter should best set up each block to provide the greatest possible performance throughout the race. Studies have been conducted to investigate the starting block placements and angles in an effort to improve the starts of sprint races as well as the overall results (Haugen T. A., 2020).

MATERIALS AND METHODS
The Research Design of this study is experimental research to improve sprint block clearance performance (100m) using block Clarence friction force production. The aim of to find out the relationship between force production and fluctuations in block pedal angles to Block Start Performance of the Sri Lankan Athletes.

Research Design
This research that employed One-Group Post-test Only Design to identify The Effect of Friction Force and Initial Acceleration in Block Start Performance.

Testing Procedure
The study area is the Biomechanical Analysis of National Level 100m Sprinters Block Start Performance in Sri Lanka. Using Purposive sampling method select population as, National Athletic 100m sprinters in Am. J. Innov. Sci. Eng. 2(2) [22][23][24][25]2023 National Athletic Pool of Sri Lanka and study sample were top 8 Ranked 100m National Sprinters in Sri Lanka National Athletic Pool (Male: n = 4, Female: n = 4) (The Elongated Starting Position). With ethics approval of the department of sports science and physical education at Sri Lanka Sabaragamuwa university. Provide Information sheet and guideline about the testing protocol. Each Athletes get data from all 16 types various foot angles using force plate which is connected to the foot pedal and 3D laboratory process.
All the Athletes are tests twice and Average Data values, graphs were considering as a result. Quantitative data statistical analyses will be performed using the Statistical. The entire data will be collected by 100m sprinter on time graphs analysis were provided by the researcher. Excel (Data Streamer Software) and SPSS software (version 27.0) are going to be used in analysing the validated data. The recorded data from the 3D motion capturing video will be analysed by descriptive data analysing (Qualisys 3D Motion Capture Analyse software).

RESULTS AND DISCUSSION
To improve block clearance performance, athletes must focus on strength and power training to enhance force production, which has a direct correlation with acceleration. Kinematic variables such as take-off velocity, take-off angle, joint angles, joint moments, ground reaction forces, flight time, and body position also influence block clearance performance. These variables interact with technique, strength, and fatigue, highlighting the need for further research to identify optimal movement patterns and the relative importance of each kinematic variable. Foot orientation, as determined by oblique lines, can also affect block clearance performance by altering force vectors and kinematic variables. Athletes should consider foot orientation when placing their feet during take-off. As a summary, the block clearance performance is a complex phenomenon influenced by multiple factors. Further research is needed to fully understand the interactions between force production, kinematic variables, and foot orientation, and to develop evidence-based training interventions to improve block clearance performance.

Statistical Data Analysis
All variables that were assessed underwent descriptive statistics. to evaluate the consistency between the two test sessions for tests 1 and test 2. For testing and follow-up tests on both extremities, the mean, range, and standard deviation for the angle of foot pendle positioning force production were recorded. (Table 1). In conclusion, there is a significant positive correlation between Front Leg Force, COG (Block Clearance) X and COG(Block Clearance) Y, and a weaker but significant positive correlation between Rear Leg Force and COG(Block Clearance) Y.

Figure 2:
The overall performance of Acceleration