Bio-Mechanic Long Jump

Force: This can be defined as a pushing or pulling action that causes a change of the state of a body. A long jumper who wants to increase their degree of force will need to increase their weight, but this can negatively affect their speed, so it is vital to get the balance right.
The law of reaction also applies to movements that occur in the air. In these situations the equal and opposite reaction is shown in movements of other parts of the body. A long jumper, for example, will bring the arms and trunk forward in preparation for landing. The equal and opposite reaction is movement of the legs into a good position for landing.
For our purposes, we will simply say that internal forces include the applied force, normal force, tension force and friction force. And for our purposes, the external forces include the gravity forces, magnetic force, electrical force, and spring force. In terms of long jump, examples of external forces that are applied to the body are gravity which is presence during the whole long jump routine, another example would be during the take when you are in the air, you rapidly move your arms down towards your legs the reaction is that your legs move upwards towards your arms (what appears to be an action and reaction). “Shown in figure 1”
On the other hand, an example of internal force can include when the muscles contract to make a force. E.g. when running the quadriceps contract, to generate internal forces that lift the whole leg, as the quadriceps enters the eccentric phase the hamstring enters the concentric phase to apply force from the leg to the ground to create motion. This is known as gravity force. Internal force is applied at the before the start as the momentum from zero velocity, to a lot of momentum through the muscle contraction which is being produced internal and has a reaction force from the ground up. That gives you the ability to accelerate and generate speed. Figure1

Applying force during take-off in long jump- This is an important part of long jump and requires a great amount of skill, which can be developed through practise. When taking off, the person needs to ensure that their hips are slightly forward of their shoulders. To prepare for the take-off in long jump, the person needs to sink their hips and then raise their hips into the take-off phase. As a result of this, the second last stride is usually longer than normal and the final stride ends up being about 20cm shorter than their normal running stride. The take-off foot needs to be slightly in front of the hips when it reaches the board to prepare for take-off. The final two-foot supporters in the take-off should be flat contacts. Vertical height is achieved by the upwards explosive acceleration of the arms and the leg that isn’t taking off. This technique is vital for force to be at its most effective. Force is absorbed through the joints, which bend or flex in response to impact.
Absorbing force- Landing is just as important in long jump because it is easy to get injured if the force isn’t absorbed properly. When the feet get in contact with the floor, it should be on the balls of the feet, followed by the bending of the ankles, knees and hips. Arms should be stretched behind the body to compensate for the weight of the legs that are stretched out in front.
The joint allows the muscles to flex and extend during the three stages, preventing injuries is a major aspect, the muscles allows to move, to gain force, speed and velocity. On the other hand the Tendons attach to muscles and bones to keep the structure of the body together during the three stages of the long jump – the linear motion, take-off and landing. It is important that there is flexion at so many joints because this decreases the chance of getting injured if the force being set through your body would be too much which will break your bones without flexion at the joints.

Biomechanics
WHAT IS BIOMECHANICS? * Is the science of movement of a living body * Includes the movement of muscles, bones, tendons and ligaments in which work together to produce movement.
WHY DO WE NEED TO KNOW IT? * Helps understand the techniques in sports * Helps understand the efficiency in movement * Helps application of knowledge within a sport
HOW CAN IT HELP YOU? * Allows both coach and player to choose the best technique to achieve best performance * Reduce the risk of injury by improving the way we move * Designs and use of equipment that contributes to improved performance

Motion
TYPES OF MOTION:
LINEAR MOTION * Motion along a straight line * Occurs when all parts of the body, travel the same distance, same direction, at the same speed. * E.g. running in a straight line

ANGULAR MOTION * Rotating body has axis of rotation * Axis might change with time * Every point in the body moves in a circle around the axis of rotation * E.g. batting, pitching, bowling

GENERAL MOTION * Combination of linear and angular motion * E.g. swimming, cycling, kicking

VELOCITY * It is the measure of both speed and direction that an object is travelling * Calculation used when an object or person does not move in a straight line * Velocity + displacement/time

ACCELERATION * Rate at which velocity changes in a given amount of time * Increase of speed quickly * All sports have an aspect of acceleration

SPEED * Those who can move quickly have a distinct advantage in sports such as, football, soccer, basketball etc. * Both for offense and defence * Distance covered divided by the time taken * Speed = distance/time
MOMENTUM
* Quantity of motion that body possesses * Momentum = Mass x Velocity
Linear momentum: * Difference of mass * Elasticity * Evasive skills Angular momentum: * Angular velocity * Mass of object * Location of mass to axis of rotation

BALANCE AND STABILITY
CENTRE OF GRAVITY * Point where in which all the weight is evenly distrivuted and about which the object is balanced * E.g. sumo wrestling, billiards, cricket * Equipment with centre of gravity: Tennis racquets and balls, basketball, soccer ball * Manipulating centre of gravity

LINE OF GRAVITY * Imaginary vertical line passing through the centre of gravity * Indicates the direction that gravity is acting on the body
BASE OF SUPPORT * Imaginary area that surrounds the outside edge of the body * Affects our ability to control equilibrium * Wide base = More balance * Narrow base = Less balance

FORCE * Force: is the push or pull acting on a body * Applied forces: Is generation by muscles working on joints * Reaction forces: Are equal and opposite forces exerted in response to applied force

HOW THE BODY APPLIES FORCE * Push or pull of objects * Push off the ground to run * Push of a tennis racquet to hit a ball * Internal forces: Muscle contraction to move * External forces: Gravity holding objects down

APPLICATION OF FORCE ON AN OBJECT * Quantity of forced applied on an object: the greater the force, the greater the acceleration * More force is required if the mass is increased * Centripetal force: Force directed towards the centre of a rotating body * Centrifugal force: force directed away from the centre of a rotating body

FLUID MECHANICS * Mechanics concerned with properties of gases and liquids * Can show performance improvement via understanding of air and water resistance * Drag, friction, lift, air resistance and flow all apart of understanding how fluid mechanics operate within sports

DRAG * Is the force that opposes the forward motion of a body or object reducing its speed or velocity * Drag is a resisting force because it acts in opposition * Amount of drag is due to: Fluid density, shape, surface, size of frontal area

Phases of long jump
There are four phases that comprises this power event. They are * Approach run up * Take off * Flight through the air * Landing
Approach run up
The objective of the approach run up is to allow the athlete to achieve ideal speed. Speed is the magnitude of the speed of the body, which is how quickly the body is moving. This is essential in the run up as the ability to attain horizontal speed or velocity that can be transferred into speed vertical speed at take-off is the key to a good jump. Rhythm within the approach is important to ensure ideal speed is achieved, as maintaining top speed throughout the run is difficult. In these phases an athlete must be accurate in order to get most out of their jump. Athletes do this with acceleration and distance. Acceleration is the increase and decrease in velocity. Accuracy is also essential to ensure the athlete does not over step the marked lines. Distances allows the athlete to feel comfortable with the amount of steps taken before the take-off board, it also determines which foot will be the take-off foot.
Take off
Preparation of the take-off begins in the later stages of the run up. An athlete prepares for take-off by sinking the hips and then raising it into the take-off phase. At take-off the athlete must adjust strides as well as to make postural adjustments. At the take-off, vertical momentum is achieved by the upward acceleration of the free limbs, the arm and the non-take-off leg. At the point of take-off an athlete must possess balance and stability. Stability is concerned with resistance of the body’s changes to the equilibrium, which are changes in linear or angular acceleration. In long jump it is known as dynamic balance as the body is moving. Being stable at the take-off board means the athlete will have a clean jump with momentum going forward and up rather than to the side which will affect the jump. The athlete’s centre of gravity also plays a major role in the vertical impulse of the jump, which works in conjunction with balance and control to ensure the athlete mains stability. Slight misjudgement of the take-off foot as land on the heels has a braking effect and jumper from the toes decreases stability. Choosing the right technique, will allow the athlete to feel comfortable which makes them stable and balanced at take-off, which will determine the end result of the jump.
Flight through the air
There are three major flight techniques: the hang, the stride jump and the hitch kick. These vary according to the athlete themselves. All three of these techniques are to combat forward rotation experienced from the take-off. The trajectory of the take-off is essential, because once the athlete is airborne; there is nothing they can do to change the direction. Athletes must maintain forward momentum to ensure they get the most out of the jump. This phase is heavily reliant on the first two phases as the athlete must build up speed and rely on life from the take-off board. Maintaining momentum through the air and having the right technique will ensure the athlete performs well overall.
Landing
During the landing the athlete is aiming to get their heels far away from the take-off board as possible. The heels must land just before the projected flight to ensure the athlete does not fall backwards into the sand, which will affect the distance jumper. As the feet land the athlete must press their heels downwards and contract the hamstring causing the hips to twist. As the hips rise, forward momentum will carry the body past the landing position. The landing can make or break the overall success of the athlete as precious inches may be lost, if technically the athlete is at fault. The reason the athletes must come down after the flight stage is due to gravity. Gravity is the force that attracts a body towards the centre of the Earth, or toward any other physical body having mass. Due to this, athletes are required to have the right technique through the landing and flight phases, to slightly help combat gravity to achieve maximal distance.
Components of fitness involved
The three major components of fitness required are speed, power and balance. * Speed – athletes must build up speed or velocity so it can be transferred into vertical velocity to ensure they get the most out of jump. * Power – once the athlete has reached top speed, they then require power at the take-off board. Power is the ability to combine strength and speed in one explosive action. This is done at the take-off board as athletes use all the force they can generate to propel the body forward and up. * Balance – stability is the key at the take-off board. Athletes must have their centre of gravity straight down the midline of the body, with momentum going forward. Without balance, athletes may jump slightly to the side, which affects the overall performance of the jump * Although these three are the essential for long jump, athletes still require muscular endurance, cardiovascular endurance, coordination and agility
Role of joints
In the run up approach the knee, the femur and tibia form a hign joint, which allows a back and forth motion (similar to opening and closing of a door). This joint allows movement in one direction which allows the athlete to build up speed as they are propelling themselves forward. This joint actions involved here are extension and hyperextension. The ball and socket joints are what join the hip, femur and the pelvic girdle, allowing circular motion. This joint is helpful when the athlete has to slightly lift the hip before landing into the sand. This hip uses flexion to allow movement during long jump.
The joints in the knee also absorb force ensuring the athlete is not injured when making contact with the ground. Also the joints and muscles within the akle allow athletes to perform the precision explosivion action which poushes the athlete up and forward. The joints help absorb the pressure placed on the ankles by gradually slowing momentum to ensure athletes do not fall backwards and to restrict injury. Joints bend and flex on their point of impact to absorb pressure making landing a breeze.
In conclusion joints combined together produced maximum effect. In long jump the hinge joint in knee and ankles help to drive them forward using speed and acceleration as well as pushing of the take-off board. Whereas the ball and socket joints in the hip allows full movement, which is essential in the technique involve once the athlete is in the air.

How biomechanics principals are used in long jump
Biomechanics principals are used from start to finish in long jump, the running include linear motion, balance and stability and force being generated through the legs to get the muscles moving causing the motion of running, without these principals the athlete will move right and left during the running part losing momentum decreasing yourself to maximum performance.
Force is used during take-off the more force generated by the muscles the greater distance you will cover.
Fluid mechanics include drag can impact your performance in the long jump phases the greater frontal shape of the athlete the more drag he is exposed to, this is decreases by wearing tight clothing reducing the amount of mass of drag helping the performer generate greater speed and momentum to having a longer jump distance.
Gravity force is applied while in the air after take-off without gravity force the athlete would stay in the air and not hit the ground, however gravity is applied in our world pushing the athlete to the ground.