An apparatus that resists against the leg as you lift your leg towards away from your body from a standing position to a wide-leg position .

Note: The same apparatus can also be changed to work as an adductor machine by manipulating the position of pins to cause resistance in a different direction.

An apparatus that resists against the leg as you contract your leg towards your body from a wide-leg position to the standing with legs together position.

Note: The same apparatus can also be changed to work as an abductor machine by manipulating the position of pins to cause resistance in a different direction.

The study of the structure (or form) of the body - it's parts and how they fit together.

The ‘hidden’ force inside an object which is accelerating constantly due to constant changes in direction - because it is traveling along a curved path, or in a circle. Objects with angular momentum attempt to conserve the relationship between their speed, their weight and the radius of the curve along which they are traveling. This is called the ‘Conservation of Angular Momentum’.

The visible effect of a force which has been transferred from one object to another when they interact. For example, the effect which a golf club has on a golf ball is ‘apparent’.

Balance in golf: The ability of the neuromuscular system to maintain the optimum alignment and center of gravity during biomechanical rotation in a golf swing.

Balance in general: The ability of an object to stay upright or avoid being tipped over. Maintaining balance involves readjusting the body's weight by using the muscles to perform, often tiny, movements (especially in the feet) which take up any changes in the body's centre of gravity. Sometimes these movements involve moving the limbs to act as counter-weights.

Balance is easiest when an object's 'point of balance' is directly below its centre of gravity, however, balance can usually be maintained as long as the 'point of balance' is anywhere within the objects 'base of support' - a triangle shaped area below the centre of gravity.

The area below an object's centre of gravity (COG) which allows it to stand without losing balance - or tipping. The base of support is usually triangular in shape, getting wider the lower it is below the COG. For example, a person standing with both feet wide apart is able to withstand being tipped over better than a person standing with both feet together - or on one foot. Basically, the lower an object's base of support (and the more central it is), the more balanced the object will be - and the less easily it will tip over. The best place for balance is along the mid-line of the 'base of support'.

The closer the COG is to the mid-line of the 'base of support' the more easily a body can be balanced. This is what is sometimes referred to as the 'Centre of Balance'. The further away it is from the mid-line of the 'base of support', the more difficult balance becomes. In some cases, trying to maintain balance when the COG and the mid-line of the base of support are far apart can lead to strain on the biomechanical system. And, if the COG of an object gets too far away from its 'base of support', it will lose its balance and fall over.

The study of the mechanics of a living body, especially of the forces exerted by muscles and gravity on the skeletal structure. The mechanics of a part or function of a living body, such as of locomotion. In this program "biomechanics" is referring to the movement of your muscles and skeletal structure during the rotation of the golf swing and the forces affecting them like centre of balance and gravity.

A biomechanical fault is due to abnormal biomechanics within the body.

The lower half of the body in the transverse plane.

A line, directly below the body's centre of gravity, along which the body can be most easily balanced. It varies in people but, generally, is located in line with the front of the second sacral segment. In this course it refers to the biomechanical mid-line of the body's 'base of support' and the way in which the body maintains the alignment of this line during a golf swing.

Centre of Gravity (or COG) - The point at which the weight of an object is equal in all directions. The 'mid-point' of a body's weight – or the 'average point' of an object's weight distribution.

(Coccyx or Tailbone) made of between 3 and 5 fused small bones.

More often referred to as muscle cells. Specialist cells in the body which have the ability to stretch and shorten in length. By contracting (and shortening) they are able to move bones at the joints. By stretching (getting longer) they release joints and allow them to move.

The imaginary plane which divides the body into two halves - upper and lower (cranial and caudal).

A spine distortion which affects the front to back (anterior to posterior) alignment of the vertebrae. For example, a kyphosis (an over-rounded convex curve of the thoracic spine causing 'rounded shoulders') or a lordosis (an over-rounded concave curve in the lumbar spine causing a 'sway-back').

The angle at which the spine and hips are tilted forward during the set-up and the swing. The coronal tilt should remain almost constant throughout the swing.

The top half of the body in the transverse plane.

When several different forms of stress combine - often resulting in the development of strain which exceeds the body's 'elastic limits' - causing damage to biomechanical system.

The force transferred between two objects when they interact without contacting each other. For example, the effect of gravity on a golf ball traveling through the air.

A change to the normal shape or position of a bone, joint, muscle or body part.

The amount of energy or force which is put into moving an object with a lever.

When the body goes beyond its elastic limit due to a single incident which causes damage to biomechanical system.

Movements of minor and small limbs (fingers, hands and toes etc) which is required for performance of Fine Motor Skills such as writing, cutting or re-balancing (especially in the feet).

Flat Feet (or 'Fallen Arches') - Caused when one or more of the foot's three arches collapses due to an injury, weakness or muscle imbalance.

When the foot 'flattens' the arch (which is on the inside of each foot) collapses and the foot rolls inwards. This turns the ankle inwards and forces the soles to point outwards. This is called a 'pronation' of the foot.

'Flat feet' can be examined in 3 main ways.

• Method 1 - By having the person stand on a flat hard floor and observing the inside of each foot to see if it has a raised arch. Two fingers should be able to fit in the space created by each arch.
• Method 2 - By having the person stand on a flat hard floor and observing the ankles from behind (as shown in the diagrams below). Normally, the feet should be vertically aligned (at 90 degrees) to the feet, at the ankles. If there is a pronation the ankle will be tilted inwards and the sole will be tilted away outwards. If the sole faces inwards it is called a 'supination'.

• Method 3 - By examining the individual's shoes to see where the greatest ware has occurred. A 'pronation' would mean more ware on the insides of the soles – especially at the heels, where most of the weight is supported. A 'supinated' ankle would mean greater ware on the outside of the shoes.

A pivot or hinge through which an effort can be transferred to a load via a lever.

When the body goes beyond its elastic limit due to the gradual accumulation of stresses until they create strain - causing damage to biomechanical system.

Movements of major limbs (arms, legs, etc) which is required for the performance of Gross Motor Skills - such as kicking, throwing or hitting.

A heavy fixed wheel spinning at high speed which generates a large amount of angular momentum. This angular momentum creates a resistance to any change in the gyroscope's position - because of the Law of 'Conservation of Angular Momentum'.

The two separate bones found on either side of the pelvis. Together with the sacrum, they help form the bowl shaped structure called the pelvis. The sacrum forms the keystone at the top (and back) of the pelvic arch and keeps the two hip-bones separated, aligned and level. If the sacrum was not able to support the hip-bones they would flounder.

The 'hidden' energy held within a stationary object due to its weight (or mass).

Kinetic energy is the energy of motion. An object which has motion - whether it be vertical or horizontal motion - has kinetic energy.

Kinetic energy of an object is the extra energy which it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its current velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. Negative work of the same magnitude would be required to return the body to a state of rest from that velocity.

Reaching the very high ‘end-point’ speeds needed for golf, requires the sequential acceleration (and then deceleration) of a series of adjoining links. As each link slows down it passes it’s momentum onto the next until, the final link in the chain receives the accumulated energy from all those before it. This is the Kinetic Link Principle and, to achieve it, requires the muscles at each stage in the series to ‘fire’ in a very specific sequence.

Kinetic links in golf can are the elbows, the wrists, the knees or the ankles.

Sir Isaac Newton was the first person to bring together many of the ideas about the Physics of moving objects.
He did this by coming up with the three 'Laws of Motion' which are explained over the next few pages. These Laws are;

• Newton's First Law -The Laws of Inertia and Momentum
• Newton's Second Law -The Laws of Acceleration
• Newton's Third Law -The Laws of Interaction

A device (usually a rigid bar) which can be used to transfer a given effort to a desired load with some kind of an advantage - known as a mechanical advantage. Levers may be classified as either Class 1, Class 2 or Class 3.

• Class 1 levers have their fulcrums in the middle - between the effort and the load.
• Class 2 levers have their load in the middle - between the fulcrum and the effort.
• Class 3 levers have their effort in the middle - between the fulcrum and the load.

The amount by which effort (to move a load) is improved when using a lever.

When two adjacent bones are not joined in the correct position at the joint. This makes movement of the joint difficult and also places pressure on the muscles on either side of it. On one side the muscles become over-stretched and on the other they become under-stretched - causing a muscle imbalance.

The 'hidden' energy held within a moving object due to its weight (or mass) and its speed (or velocity).

When two muscles have to work in unison to allow the smooth movement of a joint. While one muscle contracts, to create a desired movement, the other (paired) muscle has to relax in order to allow the desired movement to proceed. If the paired muscle does not relax and extend, the desired movement will be impaired.

The units by which force is measures - named after Sir Issac Newton, the 'father' of modern Physics. 1 Newton is the force required to move a 1 Kg weight, 1 metre in 1 second.

The pelvis is a bowl shaped structure made up of the two hip bones separated by the sacrum. The pelvis has two separate halves which can act independently if not stablised by the sacrum. The sacrum forms the keystone at the top (and back) of the pelvis - keeping both halves separated, aligned and level. The bowl shape of the pelvis helps hold the organs of the abdomen in place.

Pelvic arch - the opening at the back of the pelvis, between the two hips. This gap is filled by the sacrum which acts as a keystone for the pelvis - keeping the whole bone rigid and stable.

The study of the forces and interactions which occur between objects - either through direct contact or over a distance. Originally referred to as the Laws of Statics and Dynamics they are now dealt with by Newton's Three Laws of Motion - often known as the Laws of Physics.

Laws of Physics - The 3 basic Laws set down by Newton. The 1st Law has to do with the way force causes movement. The 2nd Law has to do with force causing objects to accelerate and the 3rd Law has to do with how objects interact with each other.

The study of the way the parts of the body function (or work) - both individually - and in combination with each other.

The final section of the spine between the lumbar spine and pelvis. It comprises 5 fused vertebrae named S1 to S5, from top to bottom.

Large triangular area of spine at base of spinal column, above the coccyx and in line with the hips. The sacrum acts as the body's centre of balance.

Two large flat bones of the shoulder on either side of the upper back connected to your arms and to which the humerus is articulated...the scapula.

Definition 1: Natural antero/ posterior curves of spine ie. kyphosis, lordosis... a spinal distortion

Definition 2: The correct angles of curvature for the three largest sections of the spine are; Thoracic Spinal Curve (35 degrees), Lumbar Spinal Curve (40 degrees) and Sacral Spinal Curve (45 degrees). These curve angles refer to the coronal (front to back) plane of the body. Therefore, distortions in either of these spinal curves can be referred to as 'Coronal Spine Distortions'.

In the sagittal plane (from right to left) the spine should be perfectly vertical. Any variation from this can be called a 'Sagittal Spine Distortion' (e.g. a scoliosis).

Either Coronal or a Sagittal Spine Distortions can cause changes in the body's centre of gravity and can lead to 'posture distortions'. Spine distortions may be due to faults in the spine itself, or to misalignments in any of the structures which support the spine - the feet, the pelvis or the sacrum. They may also be caused by imbalances in any of the muscles which support these structures.

A series of between 31 and 34 (varies with method of counting) bones (called vertebrae) - separated by inter-vertebral discs - which provide the central supporting structure for the body. It forms the spinal canal which carries the spinal cord, the major connection in the body's neurological system. The spine is divided into 3 sections: cervical, thoracic, and lumbar (lower back).

The tendency for an object to keep traveling in the same direction - or along the same line.

Strain (mechanics): the deformation of materials caused by stress induced by applied forces.

Strain (injury):, an injury to a muscle in which the muscle fibers tear as a result of over stretching

Physical stress: A force that produces strain on a physical body.

Stress in Physics: Stress is a measure of the average amount of force exerted per unit area. It is a measure of the intensity of the total internal forces acting within a body across imaginary internal surfaces, as a reaction to external applied forces and body forces.

The action of hitting the golf ball with the golf club which includes the takeaway, backswing, downswing, and follow through.

The perfect swing will have a swing arc that travels along the ideal swing plane that does not deviate from that swing plane and with a swing path travelling straight at the target.

The swing arc is the arc the club head travels along during a golf swing. A swing path is dictated by the arc the clubhead follows during a golf swing!  The arc starts in the takeaway and works around the body until the clubhead reaches the top of the swing. As the club head works back down to the ball toward the target the club 'should' follow the same arc down. When the bottom of the arc reaches the impact zone the arc dictates what path the club will follow. 

This diagram illustrate both the incorrect and incorrect swing arc. The incorrect swing arc is indicated by the blue line with arrows (that deviates in and/or out of the swing plane), and the faded golfer (dressed in blue) with the purple line with arrows shows the correct swing arc travelling along the correct swing plane.

 The direction the clubhead is moving towards the target in the impact zone during a golf swing. When the bottom of the swing arc of the downswing reaches the impact zone the arc dictates what path the club will follow. The swing path at impact can be either travelling right, left or straight at the target.

Swing paths that move too far left 'or' right of the target line are considered to be caused by faults in posture, set-up or the swing motion.

See the diagram below in "swing plane."

 A swing plane is the angle that the shaft of the club travels around the body during a golf swing.

Take-away	Down-swing	Follow-through

The above 3D illustrations show the swing plane in blue shading and blue line and the swing arc in red.
The yellow arrow indicates the swing path pointing towards the target.

When the shape of an object is exactly the same on both sides of its mid-line.

The angle at which a projectile has been launched. Usually the most effective trajectory for a projectile, to gain the greatest distance, is 45 degrees.

The speed of an object - usually measured in metres per second for scientific studies.