Motor Skill Development

Basic Movement Patterns and Performance Cues

Movement patterns is the term given to ten basic types of movement the body engages in when participating in physical activity, whether it be walking, climbing trees, skateboarding or pole vaulting. These movement patterns apply to all levels of motor skill ability regardless of whether the participant is a beginner, intermediate or advanced, recreational or competitive, female or male, younger or older.

Sending	Throwing Striking (with hands, with extention or hand or head) Kicking
Receiving	Catching Collecting
Accompanying	Dribbling (with feet, hands, stick handling) Carrying
Evading	Dodging Faking Screening
Locomotions	Repetitive displacements of the body (walk, run, climb, traverse); may involve equipment
Landings	On feet, hands, and while rotating
Statics	Balance (unstable positions) Supports (stable positions) Hangs (shoulder below point of suspension)
Swings	From various body parts From various apparatuses
Rotations	Rotation about one of the primary axes (long, broad, narrow)
Springs	Rapid displacement of the body (from arms or legs)

These movement patterns are broken down into performance cues at the beginner, intermediate and advanced levels. Performance cues are valuable for students and teachers. They provide information about specific things to look for when performing a skill in a certain movement pattern area. Click here for an example. Look under the headings Sending and Beginner. Note that when a beginner is executing a sending pattern -- and this could mean throwing a ball or frisbee, serving a volleyball or hitting a ball with a bat -- this beginner is primarily concerned with making sure that his or her body faces the direction of the target and that the feet are placed in such a way that the body feels balanced or stable.
Click here for more detail.

On the other hand, the intermediate student is comfortable with the four performance cues stated under Beginner and is focusing on five other cues with a priority placed on weight transfer. The advanced sender has the performance cues from Beginner and Intermediate under control and is working on clearing the hips and other more sophisticated performance cues.

Notice something else -- the beginner's performance cues are all related to body and space. This means that the beginner is focusing on two areas:

• how the body looks and very generally what it does when executing a skill (for example, having the body face the direction it wants the object it is sending to go) -- body

• paying attention to the area in which the body will perform (for example, the service area for tennis) -- space

The intermediate's focus is still on space but more on force. When the focus is on force, this means that the focus is on the application of power in order to move the body (starting and stopping) or applying power to a game object (badminton smash versus drop shot); however, it is useless for the intermediate student to engage in skill development at that level until the beginner performance cues have been internalized. When performance cues are internalized, it means the person no longer has to consciously think about and concentrate on them.

The same applies to the advanced student. This student is working at this level because the performance cues for beginner and intermediate are no longer a concern. This student's focus is somewhat on force but more on relationships. Here the focus is on the adjustment made among body, space and force to change or further refine skill performance and strategies (for example, applying appropriate spin on a forehand tennis shot so that it "dies" immediately after bouncing).

This information can be summarized as follows:

Movement patterns and performance cues have major implications for teaching physical education:

• They provide a quick assessment tool for determining the starting point for each student -- excellent use of the adaptive dimension!
• They provide a template for selecting and creating activities geared specifically for classes that typically contain students who are working at various levels.
• They allow students the opportunity to take control of their own learning and progress. Students are able to determine where they are developmentally and why and are able to use this information to help themselves and others improve. This in turn frees the teacher to become more of a facilitator for student learning as opposed to the being the main focus in each class.
• They allow for more objective assessment and evaluation of student progress in the motor skill domain. Physical educators will be more confident marking in this area. This eliminates the fear of what is often perceived as the unfair practice of evaluating "athletic" ability.
• They fit perfectly with the conceptual approach to teaching motor skills. The conceptual approach enables students to take what they know about one activity and transfer this knowledge to another activity. Ultimately, this means that students will be able to enjoy activities that were not specifically taught in class. It also means they will be able to participate successfully in activities that do not even exist at this point in time!

Lessons and units involving motor skill development are planned through the use of movement patterns and performance cues. Planning this way will increase the chances of students becoming physically educated as opposed to becoming physically trained. The Guidelines for Planning section contains a graph which may be photocopied and used to chart the predominant movement patterns for any activity. This will help teachers determine whether all movement patterns are being developed adequately over the course of the year or semester. Samples depicting the movement patterns for tennis and educational gymnastics are provided for illustration.

Performance Cues That Appear Most Frequently

Explanation of Performance Cues

Sending

Sending: Beginner

Body alignment

• For the best results, the body faces in the direction of the target.
• The base of support must be wide enough to provide stability. Base of support means the body parts in contact with the floor; in most cases, the feet.
• Things to know about stability and mobility:
  • Mobility is the ability to initiate movement quickly.
  • Stability means the body is firmly fixed, not easily moved.
  • When a person is standing, the upper body is heavier than the lower body. This decreases stability because the body is top heavy. In order to increase stability, the weight would have to be more evenly distributed over the body. This is done by moving the centre of gravity closer to the base of support, usually the feet.
  • Centre of gravity is an imaginary point at which the body weight is equally distributed or balanced. Generally speaking, with males this point is found around the navel. With females, it is about 5 cm lower.
  • Narrow base of support - less stability, more mobility.
  • Wider base of support - more stability, less mobility.

Limbs (working) in opposition

• This means that a right-handed person will have the left foot forward when throwing or striking an object; a left-handed person will have the right foot forward.
• This allows for more stability during the contact. (Students often say they "feel more comfortable" or that this "feels better" than same arm/same foot. Try hitting a tennis ball or a badminton shuttle with a same side contact or standing with your feet beside each other and you'll see what they mean!

Visual contact

• "Ya cain't hit what ya ain't lookin' at!" In other words, beginner students must actually see the object as it is being struck or thrown.
• Beginners tend to peek. They look to see where the object has gone before they have contacted it.
• Students who have progressed to the intermediate or advanced stages will sometimes get sloppy with this performance cue. This requires a return to the basics to find out what has broken down. It may very well be right here.

Point of release or contact

• Beginners need to spend time discovering where the best place is to contact or release the object.
• The direction an object takes is a line tangent to that in which the hand, bat, racquet is moving at impact.
• This direction is controlled to a large degree by the wrist ... another reason correct grip is so very, very important.

Sending: Intermediate

Note that these performance cues are based on a progression from beginner cues. It is pointless for a student to move from beginner to intermediate activities when the latter depends so closely on the former! Students need to be provided with activities that allow them to perform at levels appropriate to their abilities. Remember, the class is planned around the students and not the other way around.

Weight transfer

• The base of support is enlarged by moving the feet into a forward/backward or staggered position. An enlarged base of support allows for the transfer of weight in the direction of the intended target.
• When contact is made with the object, the large muscle groups of the body must be moving in the direction of the target. In order to accomplish this, the weight must move from back to front. This applies to both the body and, for example, the racquet or bat. Effectiveness is lost when the player wants the object to go to point A but, on contact, the shoulders are pointing at B, the racquet or bat face at C.

Wind-up (pre-stretch)

• If any "oomph" is to be put into the contact, the muscles must be relaxed until contact is made. It is the contracting or tightening of the muscles that gives the release or contact its force. In the advanced stages of motor skill development, the pre-stretch or wind-up is critical in that it allows the student a choice of what kind of skill to use (for example, hard smash/soft drop shot in badminton, spike/tip in volleyball).
• Balance must be maintained. If balance is lost, then the attempt at increasing range of motion and speed becomes counterproductive.
• The length of the follow through often contributes to greater accuracy due to longer time being spent in contact with the object.

Range of motion

• The length of the back swing increases and the whole arc or line that the arm or lever follows enlarges. This allows for more choices when deciding on a skill.
• Maximum range of motion allows for more time between the start of the swing and the contact/release; thus, the force at contact/release is increased. A player must learn to use range of motion effectively depending on the desired outcome.
• Use of wrist snap also determines force and direction of flight. For example, racquet sports differ in the amount of wrist snap used. More wrist snap will be used during a badminton game than during a tennis game. If wrist snap is to be used effectively, the correct grip must be used at all times!
• Range of motion increases when the wrist is cocked on the back swing.
• Follow through allows for smooth flow of the skill and allows for appropriate force to be applied to the object. For example, a complete follow through is used on a tennis serve when the desired outcome is an unreturnable serve. Less follow through is used when executing a drop shot in badminton.
• The longer the lever (racquet, arm, leg) at the time of contact or release, the faster the action. This is why students are taught to reach high when spiking a volleyball.
• If a racquet is used as an extension of the arm, the player may hit an object faster and farther than when the arm is bent. This means that the distance the racquet head is from the body has an impact on the shot.
• A squash racquet allows for more leverage because of its length; however, for the inexperienced player, it can become unwieldy. Sometimes the advantage of leverage must be forfeited in favour of more control.

Length of wind-up and follow through

• An increase in the range of motion causes an increase in velocity; for example, the farther back the student takes the badminton racquet, the faster the shuttle tends to fly.

Sending: Advanced

Again, these performance cues depend on the proper execution of the ones in Beginner and Intermediate.

Clearing hips

• Moving the hips so that the navel faces the direction the object is to go. When the student kicks a soccer ball, on the back swing, the hip opens away from the ball. As the leg moves forward, the hip comes through in the direction of the target.

Motion/movement adjustment because of velocity

• As muscles are used faster, more force is generated.
• The student comes to realize that large muscle groups (such as shoulders, buttocks) play a major role in applying force. Just because the arm or leg is doing much of the movement does not mean that those muscles are the only or even the primary ones being used. This is a common misconception.
• How large muscle groups are being used is also a logical place to look when determining the cause(s) of mechanical break downs by more experienced players. At times, these students find themselves losing their "punch". They have come to rely on weaker muscles to do a big job. This is usually rectified by a return to the basic performance cues and a review of why each one is important.

Action of Non-throwing/Striking Arm

• This arm acts by pulling or exerting force in a direction opposite to the throwing/striking arm. This helps with shoulder rotation and adds more force on release/contact. An example would be the volleyball spike. As the hitting arm comes around, the non-hitting arm pulls down, increasing the amount of shoulder rotation.

Receiving

Receiving: Beginner

Visual tracking

• The eyes must be kept on the approaching object. No peeking. As the eyes watch the object, the body will make adjustments (such as moving laterally, forward and back). This usually means moving the feet to get into position.

Presentation of target

• The body faces the direction from which the object is coming.

Absorption

• The body moves into position before the object arrives, in preparation for contact.
• Moving the feet to the approaching object instead of simply reaching for it allows for better contact and a faster recovery. Moving the feet keeps the centre of gravity inside the base of support, thereby maintaining stability. More advanced players may develop a lunge technique which, unlike a reach, still allows the centre of gravity to stay inside the base of support.

Control

• The face of the bat, racquet or stick must not deviate from facing the direction the object is to go once received.
• Proper grip is critical.

Receiving: Intermediate

Amount of absorption

• Refers to the amount of give by the receiving surface; for example, when playing at the net in tennis, if the student holds the racquet firmly, the ball will go much further after leaving the racquet than if the shot is cushioned a bit. When receiving a ground ball at shortstop in baseball, the ball is cushioned in the glove.

Hand-eye coordination

• The student has a better idea of where the object is in relation to the body and racquet, stick or foot. The racquet/stick/foot (instead of the body) ends up being positioned in the space where contact with the object is to occur. Notice how beginners often overrun the object, swing with the racquet/stick/foot too close to the body or end up having to really reach to make contact with the object.

Interception point

• Intermediate students are able to judge at what point during the flight of the object contact should be made. A high clear in badminton is contacted while the shuttle is towards the top of its arc; a forehand in tennis is contacted after the ball has bounced and close to the top of its flight path.
• For maximum force, the object must be contacted at the point of highest/farthest reach.
• The player must consider the hand, bat, etc. to be extensions of the arm and make adjustments accordingly. If maximum force is achieved with full extension of the arm, what would the player do to decrease the amount of force? Is there more than one thing a player could do?

Direction of body alignment (base of support)

• With experience and increasing confidence, students are able to gather information from an opponent's body language as well as assessing which shots are the opponent's favourites. This allows them to use centre of gravity principles more effectively. Advanced students begin to anticipate shots and angles and cheat, that is, lean to certain sides of their bodies in order to move quickly in certain directions. They have made a decision to give up some stability in order to become more mobile.

Receiving: Advanced

Setting up for next move

• Is the player setting up for rapid execution of his or her next shot? This decision is made based on body language telegraphed from the opposing player plus knowledge of the opposition's strengths and weaknesses. At this level, the player must be able to "read the situation".

Velocity of motion

• With increased velocity, the reception must be more exact; for example, to receive and return a spike in volleyball, all performance cues previously discussed will come into play, plus accurate anticipation and reaction on the part of the receiver.

Centre of gravity

• At this level, the player may have to begin absorption of the shot in an off-balance manner.

Accompanying

Accompanying: Beginner

Control

• The student is able to keep the object under control as she or he moves.
• The student understands, for instance, how hard to contact the soccer ball with the side of the foot without letting it get away. She or he understands that, when dribbling a basketball and moving quickly down the floor, the player must push the ball a bit ahead each time to prevent bumping into or over running the ball.

Visual contact

• "Ya cain't control what ya ain't lookin' at!" In other words, beginning students must actually see the hand contact the ball and/or the foot contact the soccer ball.
• Beginners tend to peek. This means they tend to direct their attention towards other stimuli (the player trying to take the ball away, the goal posts at the end of the field) instead of watching, at least peripherally, the object being manipulated. Use of peripheral vision is probably an indicator that the student has moved to the upper beginner level for this pattern and possibly even to the intermediate level.
• You may find, too, that students who have progressed to the intermediate or advanced stages will sometimes get sloppy with this performance cue. This requires a return to the basics to find out what has broken down. It may very well be right here.

Balance

• The student retains a balanced stance so that it is possible to stop quickly, and start or change direction while maintaining control of the game object. She or he should be able to stick handle to the left or right and maintain control of the object.

Absorption

• Beginning students will need time to experiment and practise with equipment to see how much absorption is required to get certain results. For example, beginning basketball players tend to slap at the ball instead of allowing the ball to move smoothly upwards from the floor into the softer, slightly cupped hand. Football players need practise to discover that when carrying a football down the field, they must relax when being tackled -- absorbing the force of the hit -- just like the hand absorbed the basketball.

Accompanying: Intermediate

Visual field

• At the intermediate stage, a student should be able to track the object using peripheral vision while maintaining a broad field of vision (that is, panoramic view of the playing field). It is not necessary for an intermediate student to have eye contact with the object at all times in order to control or manipulate it properly.

Protection of game object

• The game object should be kept close to the body whether it is being carried, kicked or dribbled. The farther the game object is allowed to get away from the body, the greater the chance of the student losing control or possession.
• The student also practises keeping his or her body in between the game object and the closest opposing player. An example would be during a soccer game where the student controls the ball with the foot farthest from the nearest opposing player.

Coordination of body and game object

• The body and the game object must work together as a unit. They must move along the playing surface at a rate that keeps the skill under control. For example, the student who is dribbling the ball down the court must keep it not only out in front but dribble it at a rate so she or he does not overrun the ball or get too far behind it.
• The student must now be able to change speeds as well as direction while maintaining control of the game object.

Accompanying: Advanced

Adjustment to external variables

• An advanced student will be able to use cues provided from other players or the specific situation itself to make judgments and then take action. That is, he or she will be able to plan the next move on a proactive rather than reactive basis. For example, an advanced soccer student will dribble the ball past an opponent on the opponent's weaker side.

Pattern variation

• The player adjusts the accompanying pattern according to various factors and game situations. These factors might include game conditions (for example, late in the period in ice hockey when there is a greater snow build up on the ice) or teammate or opponent actions.
• The soccer player can vary the distance of the kick as he or she dribbles it down the field. The basketball player may switch from one side of an opponent to the other with a spin dribble and another time use a behind the back dribble.

Faking (misdirection)

• The advanced player is able to assess external cues and use his or her centre of gravity, visual tracking and velocity to fake movement in one direction and go in another. An example would be an advanced basketball student faking a dribble to the left around an opponent and then suddenly going to the right.

Evading

Evading: Beginner

Balance maintained by upper body

• The participant will use arm extension and trunk angle to assist in controlling the body during an evasive movement.

Visual contact

• Beginners often keep their eyes focused on the direction they intend to go. As their skills develop, they learn to focus on the person they are attempting to evade and use peripheral vision when planning the evasive tactic.

Coordination

• Upper body tilt will balance out (compensate) for lower body direction and relative position of the body's centre of gravity.
• Upper limbs will often be operating in opposition to lower limbs. If the left leg is forward, the right arm will often be forward. The upper body generally reacts to the lower body.

Distribution of body weight

• Beginners tend to telegraph an evasive manoeuvre by moving the centre of gravity to the side they intend to go. They soon learn to keep their weight evenly distributed over their feet until the evasive move begins. This equal weight distribution also allows for more effective faking to one side before moving to the other.

Evading: Intermediate

Change of direction (initiated by foot plant)

• A square corner is sharper and faster than a round one. A change in direction is initiated by a definite foot plant that creates a pivot point around which the body can move. The foot plant is executed by the foot on the non-evading side. Beginners tend to run large arcs around an opponent. They begin their move too soon and take too long to perform it. Intermediate students wait longer to initiate a move, then make it more quickly and sharply.

Push off

• The foot plant assists the body in initiating momentum and direction by allowing a solid point from which to push. The push off helps the student maintain speed while changing direction.

Anticipation

• Intermediate students are performing at a level where they can begin to read the situation, picking up cues. These cues allow them to make informed decisions about what type of evasive manoeuvre to use and when. They are also better able to adjust the speed or force of the evasive manoeuvre.

Evading: Advanced

Faking (misdirections)

• Advanced students are able to assess external cues such as the opposition's body language and then use the centre of gravity, visual tracking and velocity to fake movement in one direction, then go in another.

Reaction time

• The advanced student is able to react instantaneously to external cues by processing a lot of information at one time. This information may come in the form of body language from the opposition and past experiences in similar situations. The student uses this information to make appropriate decisions. This is commonly called "playing smart".
• Quick reactions allow advanced students to maintain overall execution speed. For example, a student who is dribbling a basketball down the court can quickly evade an opponent while maintaining speed.

Peripheral vision

• The advanced student can use peripheral vision to assess game situations and make decisions. Use of peripheral vision enables the student to appear to give total visual attention to one thing when planning to do something else. For example, the offensive ringette player may focus on an imaginary or real receiver to the left thus giving the defensive player the cue that the ring or the player is preparing to move that way. Anticipating this, the defensive player adjusts his or her position accordingly. This frees up the right side of the ice which, in reality, is the direction the offensive player intended to go in the first place.

Body awareness (Kinesthetic awareness)

• The advanced student has the ability to feel where his or her body parts are in relation to the rest without actually looking at them. As the student's skills develop, this awareness extends to include a feel for the object (stick, ball, puck) in relation to the body as well as an awareness of other players and their relation to his or her personal space.

Locomotions

Locomotions: Beginner

Foot strike patterns

• moving forward: heel/ball
• moving backward: ball
• moving sideways: ball/heel/ball

Limbs in opposition

• the dominant foot is the power foot (push off).

Direction of body alignment

• The number of cross over steps used.

Centre of gravity

• The centre of gravity is kept over the base of support.

Locomotions: Intermediate

Propulsion

• Foot strike occurs in the direction of intended movement and occurs with force and strong intention.

Change of direction

• Plant the foot that is away from the intended direction of movement. This is often called "planting the outside foot".
• Pivoting.

Methods of locomotion

• Get all the limbs moving in the direction the body needs to go.

Generating velocity

• Begin the movement with short, quick steps.

Locomotions: Advanced

All body parts

• Must act as a unit (gracefully).

Controlling velocity

• Stopping quickly.

Combination of movement

• Changing direction quickly.

Landings

Landings: Beginner

Base of support

• The wider the base of support, the more stability. Beginners often perform landings with both feet or hands contacting the supporting surface (ground, floor, beam) at the same time. The feet are usually spaced about shoulder width apart.

Centre of gravity

• Upon contact with the supporting surface, the student bends at the waist (drops his or her centre of gravity). Remember, the closer the centre of gravity is to the base of support (the closer the mid-section is to the feet or hands) the greater the stability.
• At the beginner level the centre of gravity is usually over the base of support. If for some reason this is not the case, the arms or upper body tilt often compensate to maintain balance.

Landings: Intermediate

Absorption of body force/force vectors

• Typically, the greater the force vector to be absorbed, the greater the range of motion to absorb that force. For example, a person will often lower the centre of gravity more by bending at the knees and hips when landing from a height of two metres than when landing from a 1/3 metre height.

Body alignment (base of support)

• The student is able to perform successfully with a narrower base of support. This is most often achieved by extending the base of support in the direction of the horizontal force vector (a one-foot stop {landing} or changing direction with a foot plant when evading).

Pre-stretch (preparation for spring)

• After the landing has occurred, there is a relaxing of large and small muscle groups. This relaxation phase is necessary as the student often is immediately preparing for another move such as a spring. In order for the student to generate any kind of "oomph", the muscles must be relaxed so that they can then contract and generate force.

Landings: Advanced

Change of direction

• The advanced student will often land so that he or she is ready to change direction. This change of direction frequently involves vertical and horizontal force vectors (approach to volleyball spike, second basemen's pivot on a double play throw to first base).

Influence of limbs

• At the advanced level, the student learns to use his or her limbs for stability on the landing. For example, holding the arms out in front of the body while absorbing the force of the landing increases the likelihood that the individual will maintain balance. This is often demonstrated in vaulting activities, ski jumping, long and triple jumping.

Coordination

• This refers to coordinating the various body parts so that the body stays under control without a significant loss in speed or force. This is especially important when preparing to change the direction of a force vector (from horizontal to vertical or vertical to horizontal).

Statics

Statics: Beginner

Centre of gravity in relation to base of support

• Beginners need to focus on keeping the centre of gravity well inside the base of support for maximum stability.
• The larger the base of support, the easier it is to maintain balance.
• An example would be a headstand where a triangle formed by the head and hands forms the base of support and the hips are kept in an area above that triangle.

Coordination

• The trunk and all limbs must be coordinated and work in opposition in order to maintain a static or dynamic balance.

Spatial awareness

• The beginner finds it necessary to focus on where his or her trunk and limbs are in relation to a confined space. The beginner finds it easier to perform statics that keep all parts of the body close to each other.

Directional forces (force vectors)

• At the beginner level the force vectors are usually unidirectional (if they are horizontal they all go in the same horizontal direction).

Statics: Intermediate

Kinesthetic awareness (especially in inversion)

• The intermediate student focuses on what the trunk and limbs are doing in relation to each other and space in general.
• Kinesthetic awareness is particularly important when performing in the inverted or upside down position. It is not uncommon for students to experience a sense of confusion when working in the inverted position due to new visual and sensory cues.
• The limbs are often operating in opposition to each other (left foot and right arm forward).

Mental preparation

• Statics at the intermediate level require students to have a well defined picture in their minds of the activity to be performed. Visualization helps the students make a mental commitment to the skill and increases the chances of success.

Concentration

• Because the intermediate student is working with an increasing number of variables, it is critical that she or he focus totally on what is to be performed. Outside distractions are generally counter-productive.

Statics: Advanced

Altering base of support

• An advanced student is able to maintain his or her centre of gravity over a smaller base of support and still maintain balance. An example would be a one-handed handstand. The base of support (the size of the supporting hand) is very small.
• Hanging rearways (buttocks facing up) on the rings with the body parallel to the floor puts the centre of gravity below the base of support (the hands clasping the rings). Regardless, the premise remains the same: the centre of gravity must remain over the base of support to maintain balance.

Visual imagery

• A mental picture of the performance is created by the student. She or he visualizes the proper execution of the activity, often reviewing it a number of times.
• This prepares the muscles to perform an activity which the mind has already rehearsed.

Isometric contraction

• Statics are both motionless and sustained. The student learns to use strong, tight muscles to hold the trunk and limbs in an immobile position.

Swings

Swings: Beginner

Directional forces (force vectors)

• Fixed centre refers to the point(s) where the body is in contact with the bar.
• The student is aware of the centrifugal force that pulls his or her body away from the fixed centre of the swing and is able to manage that force.

Centre of gravity

• The centre of gravity is kept as far from the base as possible to maximize the effect of gravitational pull.
• At the height of a 360^o swing the centre of gravity is kept at the maximum height of the bar.

Body control

• The beginner is able to control force vectors by changing the centre of gravity during the swing.

Spatial awareness

• The beginner is able to discern where the swing will take him or her. Is the space large enough for the swing? Will the swing be suitable for the desired effect?

Swings: Intermediate

Pathways

• In order to maintain a pathway, velocity must be maintained.

Generating velocity

• Swing velocity increases as the centre of gravity moves closer to the fixed centre of the swing.
• Swing velocity can be generated by pivoting the body at major joints (hips and knees).

Swings: Advanced

Controlling velocity

• The advanced student is able to increase or decrease velocity by extending or shortening the body (piking or bending at the knees and hips).

Adjusting/controlling directional forces (force vectors)

• Changing grip at the same time the swing velocity dissipates allows for a change/reversal in swing direction.

Rotations

Rotations: Beginner

Centre of gravity

• The centre of gravity must rotate around the axis of rotation.

Limbs in motion

• Keeping limbs close to the body helps to stabilize the rotation.

Maintaining equilibrium

• All body parts must remain in rotational line in order to maintain the dynamic balance or equilibrium of the rotation.

Rotations: Intermediate

Directional forces (force vectors)

• The closer the centre of gravity is to the rotational axis the greater will be the rotational velocity.

Approach velocity

• The effect of approach velocity can be increased by tightening the rotation (making the body smaller). This effect can be lessened by lengthening the rotation (straightening the body).

Rotations: Advanced

Summation of forces

• Centrifugal force increases as rotational velocity increases. As these two forces increase, control of the body during rotation is more demanding.

Various axes

• In order to rotate successfully around two axes simultaneously (for example, a twisting flip) pathways and velocity are critical considerations.

Springs

Springs: Beginner

Body alignment

• The body should be in a ready position facing the intended direction of the spring.

Centre of gravity

• The body's centre of gravity should be positioned over the base of support.

Pre-stretch

• The student will bend at the knees and hips so that the quadriceps are stretched. Heels may be raised off the contact surface.

Release

• The legs are forcefully straightened to propel the body upward.

Springs: Intermediate

Coordinated limb movement to generate force

• The legs extending and the arms moving through a full range of motion (from back to front) will assist the student with generation of force. The pre-stretch is simultaneously, forcefully released in these body parts. The arms drive upward as the legs are straightened.

Range of motion

• The arms are used to assist the body into and through the spring. The greater the range of motion of the arms and the more acute the angles at the hips and knees, the greater will be the range of motion.

Generating velocity

• The centre of gravity is dropped prior to the spring.
• The greater the range of motion the greater is the velocity/height or distance of the spring potential.

Controlling directional forces (force vectors)

• The angle of release or projection will assist in determining the direction of the spring.

Springs: Advanced

Efficiently changing from one force vector to another

• A participant often absorbs some of the horizontal force vector by going into a partial crouch (pre-stretching) before springing for height (vertical force vector). Examples would be spiking in volleyball, approach and take off in high jump.

Controlling velocity

• Velocity can be controlled by the extent of pre-stretch, arm action and explosiveness of release.

Optimal angles

• The optimal angle of release when springing for distance (45^o) is different from when springing for height (90^o).

Influence of body parts to change momentum within a force vector

• The motion of limbs can assist in extending the force vector (for example, follow through when performing a sending skill or the "running in the air" action during the long jump).