7. General Motion

Question 1

What is general motion?

Answer 1

General motion is a combination of linear and angular motion observed in most human movements.

Question 2

How is linear motion different from angular motion?

Answer 2

Linear motion involves movement along a straight or curved path, whereas angular motion involves rotation around an axis

Question 3

What is the radius of rotation?

Answer 3

The linear distance from the axis of rotation to a point of interest on the system

Meausred in Meters.

Question 4

When a system rotates about an axis, what 3 formulas are used to make calculations?

Answer 4

Question 5

What is a radian?

Answer 5

A radian is a ratio of the distance around the the circle to the radius of the circle

Question 6

Why does a batter “choke up” (slide their hands away from the handle) on a bat?

Answer 6

Grabbing near the end of the handle increases the radius of rotation, thus increasing speed

Choking Up shortens the radius of rotation decreases speed giving the batter more control

Choking Down does the opposite to increase speed

Question 7

Describe the relationship between linear and angular variables

Answer 7

The linear change in position (translation) at any point in a rotating object is dependent on the distance from the axis of rotation (radius).

Question 8

What formula relates linear velocity (v) and angular velocity (ω)?

Answer 8

𝑣 = 𝑟 × 𝜔

where 𝑟 is the radius and 𝜔 is the angular velocity.

Question 9

How is the Direction of Translation related to the direction of Rotation?

Answer 9

The direction of linear movemnt is on a tengent to the rotating object

Question 11

What is centripetal acceleration?

Answer 11

The linear acceleration directed toward the axis of rotation, calculated using the formula:

Question 12

What is tangential acceleration?

Answer 12

Tangential acceleration refers to the linear acceleration along the path of a rotating object, calculated using

Question 13

Explain why stretching is important for performance from a biomechanical standpoint.

Answer 13

Stretching increases the range of motion, enhancing both linear and angular displacements, which can lead to improved athletic performance.

Question 14

What would need to be changed to make a faster or sharper turn?

Centripetal a (ar) = v^2 / r

Answer 14

ar increases as radius of rotation decreases, so
more force would be required to make a sharper turn

ar increases as velocity increases, so
more force would be required to make a faster turn

Question 15

When competing in a 400m race is there one lane that offers a biomechanical advantage?

Answer 15

The outer lane needs less force to turn giving it a biomechanical advantage.

However, the best lane is the 4-5th lane due to psycological reasons

Question 16

What is a - total?

Answer 16

Question 17

What does range of motion refer to?

Answer 17

Range-of-motion refers to the angular displacement attained

Stretching increases the range of motion, enhancing both linear and angular displacements, which can lead to improved athletic performance

Question 18

What is the non-linear relationship between muscle movements and joint movements?

Answer 18

Linear changes at the muscle (e.g., shortening or lengthening) and angular changes at the joint (e.g., flexion or extension) do not always increase proportionally.

Question 19

According to formulas of general motion, what is the relationship between linear and angular variables?

Answer 19

According to the formulas of general motion there should be a positive linear relationship b/w linear and angular variables

• If the linear variable increases the angular variable increases
• If the linear variable decreases the angular variable decreases

Question 20

According to formulas of general motion, what is the relationship between linear and angular variables INSIDE THE BODY?

Answer 20

There is a non-linear relationship between linear and angular variables when it comes to movements inside the human body

Question 21

What type of changes occur at the muscle?
What about the Joint?

Answer 21

Linear changes occur at a muscle
Flexion (shortening) vs. extension (lengthening)

Angular changes occur at a joint
Flexion (angle decrease) vs. extension (angle increase)