Real-World- Kick.txt

To create a larger vertical ground reaction force, you must perform the soccer kick on the hardest surface available.

To create a larger coefficient of friction, the bottom surface of the shoes that you are wearing must have 2 characteristics:

(1) the material of the soles must be soft

(2) the surface of the soles must be rough

In the golf world, the word "spike" is synonymous with the world "cleat."

To create a larger spike force, the spikes attached to the bottom of your shoes must have 3 characteristics:

(1) the must be able to penetrate ground surface

(2) they must be long

(3) the must be wide

To create a larger muscle force, three factors that influence the size of the muscle force must be considered.

(1) Muscle Size

-a muscle with a larger physiological cross

-sectional area will create more muscle force-increase via resistance training

(2) Muscle Length

-muscles stretched to 120% of their natural resting length generate the most muscle force

(3) Speed of the Muscle Contraction

-muscles that are concentrically contracted at slower speeds generate greater force than muscles that are concentrically contracted at faster speeds

HIP INTERNAL ROTATION

• Adductor Brevis/Longus/Magnus
• Gluteus Medius/Minimus
• Gracilis
• Pectineus
• TFL
• Semitendinosus
• Semimembranosus

HIP FLEXION

• Adductor Brevis/Longus/Magnus
• Gluteus Medialis/Minimus
• Gracilis
• Iliacus
• Pectineus
• Psoas Major
• Rectus Femoris
• Sartorius
• TFL

KNEE EXTENSION

• Biceps Femoris
• Gluteus Maximus
• Rectus Femoris
• Vastus Intermedius/Lateralis/Medialis

The distance from the joint's axis of rotation to the line of pull of the muscle force.

To increase the moment arm distance, you would need to move the line of pull of the muscle force further away from the joint's axis of rotation.

One method for moving the line of pull of the muscle force would be to change the locations of the origin and insertion points for the muscle. It would be unethical to perform this type of surgery.

The only way we can change the moment arm distance is by changing the angle of the joint. When the long axes of the two bones connected at a joint are aligned long axis to long axis (straight line), the moment arm distance is the smallest.

SHORT-TERM

(1) wear the lightest clothing possible

(2) wear the lightest shoes possible

LONG-TERM

(1) lose fat mass

The distance from the joint's axis of rotation to the center of mass of the body component.

Individuals with shorter bones will have shorter radii of resistance. There is nothing we can do to decrease bone length.

We can change the radius of resistance by changing the angles of the joints within the body component being rotated. We can decrease the radius of resistance by rotating the body component closer to the joint axis of rotation.

To increase the application time of the concentric left hip internal rotation joint torque:

DURING THE PREP PHASE

the left hip must be externally rotated

DURING THE EXECUTION PHASE

a concentric left hip internal rotation joint torque is applied until the left hip is maximally, internally rotated

To increase the application time of the concentric right hip flexion joint torque:

DURING THE PREP PHASE

the right hip must be extended

DURING THE EXECUTION PHASE

a concentric right hip flexion joint torque is applied until the right hip is maximally flexed

To increase the application time of the concentric right knee extension joint torque:

DURING THE PREP PHASE

the right knee must be flexed

DURING THE EXECUTION PHASE

a concentric right knee extension joint torque is applied until the right knee is maximally extended

The distance from the joint's axis of rotation to the point of interest on the body component.

Individuals with longer bones will have longer radii of resistance. There is nothing we can do to increase bone length.

We can change the radius of rotation by changing the angles of the joints within the body component being rotated. Any change in a joint angle that rotates a portion of the body component farther from the axis of rotation will lengthen the radius of rotation.