Motion

The biomechanical principle of motion relates to linear motion, velocity, speed, acceleration, and momentum. Motion is a movement that results from a force. In any physical activity, there are multiple forces and motions occurring. This could include angular motion around a joint or the motion of the whole body in various directions. The motion or movements of the body are often caused by forces produced by our muscles, but this is not always the case. For example, if an opposition player pushes you to the ground, the force has come from them, and not your own muscles. 

Motion can be linear, angular or general. The type of motion is determined by the direction of movement. The only type of motion you are asked to understand is linear motion. In order to properly apply velocity, speed, acceleration and momentum the other types of motion should also be defined.

Angular motion is motion in a circular movement around a central point, for example a hammer throw in athletics: The hammer moves in a circular path around the athlete before release. Essentially every movement of your body at a joint is angular. General motion is a combination of linear and angular motion, such as completing the 400m sprint.

Linear Motion

Linear motion is movement in a straight line. Our body produces forces that cause angular motion at our joints which are then combined to cause linear motion of our bodies. This is known as general motion. An example of linear motion in sport is a ball moving in a straight line, or when an athlete, such as a downhill skier, holds a particular body position as they move in a straight line. Another example is a swimmer when they glide off the wall. You can determine if the motion is linear by drawing lines connecting each body part between the start and finish if the lines are the same length it is linear motion.

When it comes to performance most motion is general (a mix of linear and angular) since motion is created by the angular movement of the limbs around their joints. This does not change the fact that the 100m sprinter needs to run the shortest distance possible in the race, which is a straight line. Therefore, the more linear their motion, the better their performance. The same can be applied to sports such as swimming and ski jumping. In these sports, the better the athlete can maintain linear motion, the better their performance will be (even if their motion is general).

Velocity 

Velocity is the displacement of an object over time and includes direction. So, an athlete might have a velocity of 17 Km/h in a southeast direction. Velocity is different from speed, which does not have a direction attached to it, and is the distance the athlete covers in a specified time. So a football player might average 12 Km/h during their match, or might be moving at 8 m/s at a specified time.

The difference between velocity and speed becomes apparent when comparing them in a 400m race for the athlete in lane 1. The athlete’s speed for the event may have been 7.89 m/s, but her velocity is zero since she started and finished at the same point.

When it comes to performance, velocity and speed often have a similar impact. For timed races, the higher the athlete’s speed the faster they will complete the race. Velocity is related to speed but varies according to displacement from the original position and direction. For example, in a 100m race, the velocity and speed will be the same. If we are talking about the movement of a cricket ball through the air, velocity is a better measure, as it takes into account both the horizontal and the vertical movement of the ball, which combine to provide the ball’s velocity.

Acceleration

A change in velocity is known as acceleration. Such a change can be a change in linear motion, such that the “speed” of the object increases, or it can simply be a change in direction. Acceleration is caused by applying a force to an object, whether stationary or moving. Acceleration can be positive or negative (often called deceleration) depending on whether the change in velocity is positive or negative.

Acceleration can also be uniform or varied. Uniform acceleration is when there is a constant change in velocity, such as gravity acting upon a discus flying through the air. More often, the acceleration is varied. This could be from an opponent tackling a forward in rugby, with changes in velocity, including positive and/or negative acceleration, and multiple changes in direction.

Acceleration is a vital component of performance and relates directly to the athlete’s ability to produce power. Athletes use accelerationsport as they change their velocity to beat opposing players, such as in the video above of Messi, or to begin a race. Faster acceleration is beneficial in performance, as it allows opposition less time to react, and helps you reach your top speed faster. A change in velocity occurs as a result of forces acting upon the object or body.

Acceleration relates directly to agility and its use in sports performance and movement contexts. The ability to change direction at speed requires fast changes in velocity; therefore, faster acceleration allows for better agility.

Momentum

Momentum is a quantity that represents the motion of an object, determined by multiplying its mass by its velocity.. Because momentum is calculated using velocity, it is a vector. That is, it has both direction and magnitude. This means that when you describe the momentum of a mass, you must provide its direction.

Momentum = Mass (Kg) X Velocity (m/s)

Momentum is directly related to the velocity of the object and its mass (often called weight). Therefore a larger object moving at the same velocity as a smaller object will have greater momentum. Momentum relates to force because force is the rate at which momentum changes with relation to time. When thinking about the size of an object’s momentum, we should also think about the amount of force it took to provide the object its motion, and how much force would be required to stop the object from moving. So the heavier object (with a larger mass) moving at the same velocity as a lighter object will require more force to stop its velocity, and take more force to get to its current velocity.

For sports performance, all objects have mass, and therefore when in motion, have momentum. Momentum is particularly important for contact sports such as rugby league. Here the forward, who is often heavier, builds up his momentum as he makes his run. This momentum requires a large force from the opposition in order to stop the motion. If the forward runs into a lighter player, the lighter player will struggle to stop the motion of the heavier forward because the forward will generally have larger momentum, even if they are moving at the same velocity in opposite directions.

Momentum is also related to acceleration. In order to accelerate, the force acts upon an object. 

The heavier the object the larger the force that is required to move it, and the motion will be slower than a lighter object that receives or produces the same force. So the lighter full-back can move faster and accelerate more quickly than the heavier forward because the forward requires more force to reach the same velocity.

Another example can be seen in the 400m sprint. Throughout the sprint, the athlete needs to accelerate, at the beginning by increasing their speed, but as they turn corners, they need to change direction, which is also acceleration. In order to change direction, the athlete must create a force that causes them to move. This is because the athlete already has momentum in a particular direction, and needs to have another force act upon themselves (produced by their muscles and the ground) to change their momentum from one direction to another. So here, the change in momentum, may not mean a change in speed, but a change in direction (a change in velocity).

Balance and Stability

Balance and stability are separate concepts that are highly related. Balance is a person’s ability to control their equilibrium in relation to gravity only, whereas stability is the body's ability to “return to a desired position or trajectory following a disturbance to equilibrium. Equilibrium is a state of no acceleration and can be static (without movement) or dynamic (moving at a constant velocity). Therefore, balance can be categorised as either static or dynamic, depending on whether the body is stationary or in motion, but it requires the absence of acceleration. For example, a gymnast holding a handstand perfectly still has static balance whereas dynamic balance is when a cyclist maintains stability while riding at a constant speed in a straight line. 

If acceleration is occurring we are talking about stability, as our body needs to respond to the acceleration (whether the force is internal, from our own body, or external, from outside our body) and return to a desired position or trajectory. This could be as simple as changing direction, or as complex as completing a vault or responding to an attempted tackle from an opponent.

Many processes are involved in maintaining balance and stability in sport, and athletes who have to respond to a disturbance will often shift their body to better enable them to return to their desired position or trajectory. For example, when two forwards in rugby collide, they will often lower their body and spread their feet wider before contact in order to better enable them to remain stable.

Centre of Gravity

The centre of gravity is the point where gravity appears to act on an object, typically coinciding with the point where the object's or person's mass is evenly distributed in all directions.. For most individuals, the centre of gravity is at the centre of the pelvis when they are standing in the anatomical position. The centre of gravity shifts slightly upwards for males due to their larger shoulder mass, but centre of gravity is always athlete specific. This means that an athlete with larger legs will have a lower centre of gravity unless their upper body is also large and balances the mass.

The centre of gravity moves according to the athlete’s body position. For example, a runner’s centre of gravity is in the lower region of the pelvis and in front of the body, because the upper body is leaning forwards. Having the centre of gravity lower and in front of the lower body is advantageous for acceleration.

Lowering an individual’s centre of gravity also helps to increase stability because it needs to be lifted higher before it moves outside of the base of support. This becomes very useful in combat sports such as 

jiu jitsu or sumo wrestling. It is also used by blockers in the NFL or to create a more effective rugby league tackle.

Lowering the centre of gravity increases balance and stability in sport. This is why you can change direction faster by bending your legs and getting lower to the ground. It increases your stability, allowing you to adjust to greater force production by the legs.

Line of Gravity

The line of gravity is an imaginary vertical line from the centre of gravity to the ground or surface the object or person is on. It is the direction in which gravity acts upon the person or object.

The location of this line in relation to the base of support has a huge influence on balance and stability. In the anatomical position (right) the line of gravity is between the legs and feet right under the person. 

The closer the line of gravity is to the centre of the base of support the better balanced a person is in this position. If the line of gravity falls outside of the base of support the person must provide corrective muscle action, usually movement otherwise, they will fall. This is why the sprinter’s line of gravity is in front of his base of support (back foot on the ground) because it must be there in order for him to be stable and move forwards. If the line is in his base of support and he starts running, he will fall backward, unless he moves the line in front of him.

Since a lower centre of gravity means better balance and stability, a shorter line of gravity between the centre of gravity and the ground also means better balance and stability. So a rugby player dodging through the defence will shift his line of gravity outside of her base of support in various directions. As the athlete changes direction, they will also lower their centre of gravity.

Base of Support

The base of support is the area around the outside edge of the sections of your body in contact with the ground/surface. 

The larger the base of support the more stable the person/athlete is able to be. When an athlete is anticipating contact from an external player, they will naturally widen their base of support in the direction of force (or impeding force). That means that if you are about to have a forward run into you in a game of rugby league, you don’t abduct at the hips and widen your support, as this will not help you. Instead, you stagger your feet front to back in order to increase your stability. 

Widening your base of support also makes you less mobile. In order to increase mobility and improve acceleration an individual needs to reduce their base of support. For example, a rugby player who is weaving through their opponents has a small base of support, which makes them more agile, but also less stable. 

When there are big changes in direction, stability is often increased by adding contact points. Whether having two feet on the ground to step an opponent or putting a hand on the surface of a wave when turning. Often the hand in surfing provides limited support, as the water does not provide the same stability as the ground, but it does increase your stability.

When it comes to movement the athlete seeks to keep their line of gravity outside their base of support to create acceleration and continued movement. As with a sprinter who puts their line of gravity in front of their base of support in order to allow stability in movement. The further the distance from the base of support, the greater acceleration is required to maintain stability. Once a set velocity is reached, the line of gravity is often brought back closer to the base of support, as the body becomes more upright in order to maintain the velocity with both balance and stability.

Source: Brendan Burkett. Basic principles for understanding sport mechanics. http://www.humankinetics.com/excerpts/excerpts/basic-mechanical-principles

Fluid Mechanics

Fluid mechanics is the study of forces and flows within fluids. Fluids include plasmas, gases and liquids creating forces on each other and the object within them. Within sport, the forces of the fluids upon objects and people impact performance. Athletes often spend lots of time practising being able to manipulate these forces using variations in technique in order to refine their skills and improve their performance. 

Athletes often spend lots of time practising manipulating forces using variations in technique for the purpose of refining their skills and improving their performance. An example of this is the football player rehearsing their free kicks to perfect the ball's placement and movement through the air. Sports scientists are often used to assist in the design of new clothing or equipment in order to allow for improvements in athletic performance by manipulating the forces provided by fluids. Examples include, the full-length swimsuits, with swimming caps and goggles used to decrease fluid resistance, and the addition of dimples in the golf ball or the fuzz on a tennis ball to create more lift and control through the air. 

Flotation

Floatation is caused by a force known as buoyancy. For an object to float in water it must be less dense (mass per unit of volume) than the water.

When an object is placed in water it causes the water to be displaced (move upwards). This can be seen when a person gets into a bath and the water rises. If the bath is filled to the brim, the water that is displaced will pour out of the tub when the person gets into the bath. In order for an object to float, the water they displace must weigh more than they do.

In order for an object to float, the water they displace must weigh more than they do. This is essentially because gravity is seeking to push the water that has been displaced, back down, while also pushing the person down. If the gravitational force on the water is greater than the force on the object, then the water will create a buoyant force that will push the object upwards against gravity. Once the two forces become equal the object will float in this position, which is known as the point of equilibrium. That is, the part of the object below the water has displaced the same weight of water as the object itself, resulting in a buoyancy force equal to that of the gravity force acting on the object.

Centre of Buoyancy

The centre of buoyancy is the centre point of the mass below the water and is the point through which the buoyant force acts. This is much like the centre of gravity – the point through which gravity acts, but buoyant forces act in the opposite direction. In order for the object to not rotate in the water this buoyant force must pass through the centre of mass of the object, if they do not line up the object will rotate until they do, such that one end of the object will sink further while the other end raises.

For an object to have less gravitational force than the water it displaces it must be less dense (mass per unit of volume) than the water. Not all water has the same density though. Salt water is denser than freshwater, and the saltier it is the larger the density. This means it is easier to flow in the ocean than it is in a pool.

Flotation and centre of buoyancy relate to performance because the higher an object floats in the water, the less resistance the water will create to its movement. This applies to all water sports, including: surfing, kayaking, sailing, skiing, dragon boat racing, water polo, synchronised swimming, and swimming. These forces also relate to scuba diving, where the person is seeking to sink below the water and remain submerged. In this instance, the person, with their gear, wants to be the same density as the water in order to allow them to remain submerged easily, but not have to fight too hard to return to the surface. This is often achieved using weight belts.

Fluid Resistance

Forces act on us when an individual attempts to propel ourselves through a fluid environment. These forces include drag force and lift force. Elite athletes understand and use these forces in a way that will benefit the efficiency of their performance.

Fluid resistance refers to the forces a fluid places on a moving object in the opposite direction to the movement, also known as drag. Drag is the force created by a fluid to resist the motion of an object through it. There are 2 main sources of drag: pressure (form) and friction.

Pressure drag is the force resulting from changes in fluid pressure as an object moves through it. Initially, the pressure increases at the front of the object as the fluid is displaced to flow around it. For example, if you've felt a rush of "wind" from a fast-moving vehicle like a truck or train, that's the air responding to the increased pressure caused by the object's motion, pushing the air away.

At the rear of the object, there is another change in pressure, this time a decrease in pressure. This lower pressure in the fluid causes the fluid to move in towards the object that is moving to fill in the space it leaves behind it. The movement of this fluid at the back of the moving object is often referred to as turbulence. You can see this low pressure behind the car to the right as the air moves back in behind the car.

Different shaped objects create various amounts of pressure drag. The more front on the object, such as a square, the more pressure drag created. This can be seen as the fluid has to move more widely, creating more turbulence behind the square. Whereas a streamlined foil creates less pressure drag due to its shape causing smaller changes in pressure. This is known as streamlining, where the object becomes as narrow and as straight as possible.

An example of pressure drag being used to the athlete’s advantage comes in skydiving. Here the athlete uses the pressure drag to control their fall and then, with the release of their parachute, rely on it for safety.

The other form of drag is caused by friction between the air particles moving past the object and the surface of the object. In many sports, particularly swimming, clothing and equipment have been adjusted to cause less friction. Examples include the swim cap, goggles, and swim suits that cover larger portions of the body, such as the full-length suit, which was banned from competition in 2010. Similar, full-length suits have been used in sprinting as well, including the suit worn by Cathy Freeman in the 400m at the 2000 Olympic games in Sydney.

Athletes have also used fluid resistance to their benefit in multiple sports involving balls.. Whether it be football, rugby, Rugby League, AFL, tennis, golf or netball; athletes have learnt to use fluid resistance to change the movement of the ball through the air.

The easiest example of this is the athlete using what is called the Magnus effect. The Magnus effect refers to the use of spin on a ball and the resultant changes in force that cause the ball to move in the air. When a ball spins through the air, it captures a layer of air around its surface. This air then collides with the air the ball is moving through, causing the air to slow down and cause high pressure on the side where the ball and the air caught on its surface are moving in the opposite direction of the air going past the ball. 

Conversely, on the other side of the ball, the layer of air moves in the same direction as the air going past the ball, therefore speeding up the movement of air, and causing low pressure. This pressure difference then makes the ball move in the direction from high pressure to low pressure.

Of course this does not apply only to top and back spin. If the ball is spinning sideways, then the ball will move in the direction of the spin on the ball. As seen in the video below of free kicks in football.

Changes in technique, such as the curved free kick or the use of top and back spin in tennis and athletes also streamline their body in the water when swimming. Clothing modifications, such as the full length bodysuits in swimming and sprinting which help to reduce drag. Equipment such as parachutes use drag to safely bring the athlete to the ground safely.

Other equipment advances include the addition of dimples on the golf ball, which help reduce turbulence and drag by capturing a thin layer of air around the surface, and using pointed kayaks for racing to cut through the water, helping reduce form (pressure) drag.

Drag Force

Drag force is sometimes referred to as resistance, and is the resistance that acts against a body as it moves through a fluid environment. Friction occurs when one body moves across the surface of another. Friction will always oppose motion. A pressure difference occurs to the opposing sides of the body in the water and these act to propel the body forward. When swimming, a low-pressure area is created in front of the hand, and a corresponding high-pressure area forms behind the hand, as the hand pushes the water back, the drag forces propel the body forward.

Lift Force

Lift force is often referred to as hydrodynamic lift force when created in the water. It is much greater than the lift created in the air, as water is denser. This force occurs perpendicular to the flow of the water over the body when swimming. When performing an eggbeater kick in water, hydrodynamic lift force is created as the legs alternatively circle under the water, creating pressure differences between the top and bottom of the leg and foot. The lift force acts to push the athlete upwards. Swimmers experience a lift force as they stroke the water, as the flow of water over the hands creates a forward lift equal to the force exerted by the swimmer.

Force

Newton’s laws of motion are:

1. Every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force. An object will remain in constant velocity until a force acts upon it to change the velocity.

2. The rate of change of momentum of an object is proportional to the force causing the change and occurs in the direction of the force. That is, when a force acts on an object, the change in the movement will be as large as the force and in the direction of the force.

3. For every action, there is an equal and opposite reaction. This means that when a force is applied to an object, the object applies the same force upon that which is applying the original force, but in the opposite direction.

These three laws all relate to force and the motion of objects. They are highly relevant for sport and the biomechanical principles of human movement.

The body creates force by manipulating the gravitational force on the body and by generating force using its muscles. Muscular contraction provides the force used to create movement around joints. Most of the forces of the body act using a lever system, which converts a smaller input force (from muscles) into a larger output force. 

In order to complete the vertical jump test, the athlete will first load the legs by squatting down, allowing gravity to push the athlete towards the ground. The athlete will then contract the muscles in their legs and butt in order to push down into the ground and also contract their arm muscles to swing their arms vertically into the air.

Gravity and the lower body muscle contractions create a force in the downward direction into the ground. This force is then met by an equal and opposite reaction force that propels the athlete into the air. The greater the downward force the greater the reaction force, and the higher the athlete jumps. Further upward force is generated by the vertical acceleration of the arms to create a thrust in the vertical direction.

If the force applied to the ground is not directly vertical, then the athlete will move in the opposite direction of the force. So if they create a force that is both downwards and backwards, they will jump forward.

For sprinting events, the athlete' needs to get out of the blocks quickly. For this to happen, the athlete needs to apply a force in a downward and rear direction in order to have a reaction force that propels them forward. In order to increase this force, the athlete gets low to the ground and angles their body forward so that they can generate a larger force in the backwards direction and accelerate their body in a forwards direction.

The Body Absorbing Force

Our body absorbs force by transferring the force to our muscles, where contractions in the opposite direction absorb the force. Our bones and body tissue also absorb some force, but within sport most of our force absorption occurs in our muscles. In order to absorb large forces safely, our body seeks to absorb the force by increasing the time of absorption, increasing the movement length used to absorb the force, or increasing the area in which the force is absorbed. The body will also apply a force in the opposite direction, usually using an eccentric contraction.

In order to increase the safety of the landing, the athlete can make the eccentric contraction go for longer by allowing a larger bend at the joints. Alternatively, the muscles can create a more forceful contraction to absorb more force over a shorter period, though this is harder to control.

Another example can be seen when catching a ball. The body absorbs the force from the ball through eccentric contractions in the shoulders, trunk and arms. These contractions absorb the force over a longer period of time, making it easier to control and increasing the chances of the athlete holding onto the ball.

How the body absorbs force relates to movement and performance, because the longer the reaction force, or eccentric muscle contraction, the more control the athlete has over the movement. Performances such as catching in the field for cricket or baseball are improved by greater control over the ball's movement and extending the period over which the force is absorbed.

It is similar to gymnastics, where athletes often have to “stick” the landing. Here the better they are equipped to absorb the force over a set period of time, the better their landing will be as it will be controlled. Sports equipment is often used to help absorb forces, such as the gloves of a wicket keeper, or catcher, the mats used in gymnastics, or the sand in long jump. 

All help to absorb the forces in the sport.

Force and Sports

Frequently in sport the body is the vehicle used for applying force to an object. This could be the swing of a racket or bat applying force to a ball, or the movement of a foot to kick a ball, or even the use of an athlete’s body to tackle their opposition. The body does this by generating forces by its muscles, creating movement of the limb or body that makes contact with the external object.

In order to generate the maximal force, the body needs to use its largest muscles. Even when the upper body is used to make contact with an external object, the force is often generated from the lower body. Take shot put as an example: athletes rely on technique by bending their legs to generate power from their lower body. This force is then amplified by their torso as they twist, followed by a final push with their arms. Additionally, they harness centrifugal force created by their spinning motion to maximise their throw. An athlete who throws and bends their legs generates their force from their legs. They then add force from their torso, as they twist their body, before the final push with the arms. They also add centrifugal force generated by the spin.

The body can also help generate force, by using gravity and momentum from movement and transferring the force into the object. This can be seen in a power shot in football, where the athlete will take a run up, to generate momentum. When they then plant their foot next to the ball before kicking it, they will bend the planted leg, drop their centre of gravity and then use the muscles in their torso and legs to generate the force of the kick, which will include a swinging motion at the hips and twisting at the torso. Such technique can be seen as the athlete’s use of the ‘knuckle ball’ shooting technique, to not only apply large forces to the ball, but also to cause the ball to move around unpredictably in the air.

The last example of applying force to an object is the rugby tackle. The athlete seeks to apply a force to their opposing player in order to bring them to the ground. Various tackling techniques can be used. The first technique requires the tackler to step forward toward their opponent and drive with their legs forward and upwards. The aim is to stop the athlete’s momentum, and lift their centre of gravity to make the athlete unstable, before putting them on their back. This tackling technique relies on the tackler being able to produce a very large force on their opponent.

For a smaller tackler this type of tackle is not safe, as the forces from the opposition will cause him to fall off the tackle. Instead, such tacklers seek to apply forces in other directions, such as sideways, or downwards. A smaller force is then required to bring the opponent to the ground because the tackler aims to cause the runner to lose balance, rather than counteract the athlete's momentum. In fact, if done well the momentum of the runner should assist the tackler.

These are just a few examples of athletes using parts of their body in applying force to an object. Angular momentum around joints and how the longer the lever the faster the movement at the end could also be explored, resulting in greater forces being applied to the object (why individuals kick with their feet and not their knees or hit with their hands and not their elbows).

How biomechanical principles can be used to enhance safe movements

Biomechanics is the study of the mechanics of biological systems, including human movement. By applying biomechanical principles, an individual can improve the safety and efficiency of movements.

Biomechanical principles:

Motion: Understanding the principles of motion, such as speed, velocity, acceleration, and momentum, helps us to analyse how our bodies move and interact with the environment. For instance, understanding the concept of momentum can help us to control our movements during activities like running or jumping.

Force: Forces act on our bodies to produce movement. By analysing the direction and magnitude of forces, potential hazards can be identified and improvements in technique can be made. For example, understanding the concept of ground reaction force can help us to reduce the risk of injuries during landing from jumps.

Fluid Mechanics: When an individual moves through fluids (like air or water), fluid mechanics principles apply. Understanding these principles can help us to improve our performance in sports like swimming or cycling. For example, understanding the concept of drag and buoyancy can help swimmers improve their stroke technique, reducing the risk of injuries like shoulder impingement or swimmer's shoulder.

Stability and Balance: Maintaining stability and balance is essential for safe movement. By understanding the principles of centre of gravity, base of support, and equilibrium, individual’s can improve our balance and coordination. For example, understanding the concept of centre of gravity can help us to maintain balance while standing on one leg.

Common injuries that can result from poor technique include:

Strains: Overstretching or tearing of muscles or tendons.

Sprains: Injuries to ligaments, which connect bones together.

Overuse injuries: Conditions that occur when a joint or muscle is subjected to excessive stress.

By applying biomechanical principles, an individual can rectify these issues and improve our movement safety. For example, by using proper technique during weightlifting, athletes can reduce the stress on their joints and muscles and reduce the risk of strains and sprains. Similarly, by improving balance and coordination, an individual can reduce the risk of falls and other injuries.

Understanding and applying biomechanical principles is essential for safe and efficient movement. By analysing the forces acting on our bodies, athletes can identify potential hazards and improve their technique, reducing the risk of injuries and enhancing overall performance.

Specific examples

Understanding biomechanical principles can significantly enhance the safety and efficiency of everyday movements like walking, squatting, and lifting. By analysing the forces acting on the body during these activities, an individual can identify potential hazards and improve their technique to reduce the risk of injuries.

How biomechanical principles can be used to increase movement efficiency

By understanding and applying biomechanical principles, an individual can improve the efficiency and safety of their movements.

1. Movements to Reduce Injury

Proper Form: Using correct technique can help to reduce the risk of injuries. For example, maintaining a neutral spine when lifting heavy objects can help prevent back pain.

Warm-up and Cool-down: Adequate warm-up and cool-down sessions can help to prepare the body for physical activity and prevent injuries.

Progressive Overload: Gradually increasing the intensity, duration, or frequency of exercise can help to prevent overuse injuries.

Rest and Recovery: Allowing sufficient time for rest and recovery between workouts is essential for preventing fatigue and injuries.

2. People with Specific Need:

People with a Disability: Biomechanical principles can be adapted to help individuals with disabilities improve their movement efficiency. For example, assistive devices like can be designed to optimise movement and reduce the risk of injuries.

 - Person who uses a wheelchair: Biomechanical principles can be used to design wheelchairs that optimise propulsion efficiency and reduce the risk of injuries. For example, analysing the forces exerted by the arms during propulsion can help to design more ergonomic handles.

 - Person who has experienced limb loss: Prosthetics can be designed using biomechanical principles to mimic the function of the missing limb, improving movement efficiency and reducing the risk of complications.

Age: As people age, their physical abilities may decline. Biomechanical principles can be used to develop exercise programs that are safe and effective for older adults, focusing on balance, strength, and flexibility. For example, tai chi and yoga incorporate biomechanical principles to improve balance and reduce the risk of falls.

Specific Conditions: For individuals with specific conditions like arthritis or osteoporosis, biomechanical principles can be used to develop exercise programs that are safe and effective.

 - Arthritis: Biomechanical principles can be used to design assistive devices and exercise programs that reduce joint stress and improve mobility for individuals with arthritis.

 - Parkinson's Disease: Exercise programs based on biomechanical principles can help individuals with Parkinson's disease improve their balance, coordination, and mobility.

 - Cerebral Palsy: Physical therapy using biomechanical principles can help individuals with cerebral palsy to improve their movement patterns and reduce the risk of secondary complications.

By applying biomechanical principles, individuals can improve their movement efficiency, reduce the risk of injuries, and enhance their overall quality of life.

Biomechanical Principles Applied - Walking

Refer to the table below.