Week 1

Question 1

What does a moment of inertia mean?

Answer 1

moment of inertia is the ability to move an object in an angular motion

Question 2

Explain what happens to control as degrees of freedom increase at a given joint.

Answer 2

The more freedom the more muscles you need to control it.

Question 3

What combined actions of the foot cause pronation or eversion?

Answer 3

• Dorsi Flexion
• Abduction

Question 4

Definition of Kinematics

Answer 4

Branch of biomechanics that deals with the description of movement without regard to causes of movement

Question 5

Instantaneous axis of rotation

Answer 5

The change in the axis positioning in relation to total movement.

Question 6

What is the equation for the moment of inertia?

Answer 6

Question 7

Explain what is meant by “gravity eliminated” action in regards to patient care.

Answer 7

This is a positioning of a patient in which the need for a joint to appose gravity is not present.

The action typically causes the action to go through the transverse plane.

Question 8

Conceptualize movement!

Answer 8

Movement is a perpetual state of momentum transfer.

Transfer from legs to hips to shoulder to arms to hand to wrist to the action of throwing a ball.

Question 9

What happens to the angular momentum of a fixed distance system if the mass is increased?

Answer 9

If we increase the mass of an object we increase the total inertia of that system thereby increasing angular momentum.

Question 10

What is a distraction force?

Answer 10

This is the net force that moves a boney segment away from its adjacent segment.

Question 11

Definition of Statics

Answer 11

Branch of mechanics that deals with forces in the absence of changes in motion.

Question 12

What are the internal causes of movement?

Answer 12

• Muscle Contraction
• Elasticity

Question 13

As the mass of an object moves closer to the axis of rotation does the effort required to move it become easier or more difficult?

Answer 13

As we move closer it becomes easier.

Question 14

What is the center of pressure?

Answer 14

This is the point in a system where force is applied.

Question 15

What is the equation for angular momentum?

Answer 15

Question 16

Definition of Kinetics

Answer 16

Branch of biomechanics that deals with the causes of movement

Question 17

Definition of Dynamics

Answer 17

Branch of mechanics that deals with the effect that forces have on the motion of objects.

Question 18

How do we determine linear velocity?

Answer 18

Question 19

As we transition from novice to expert what happens to the relationship between muscle contraction and elasticity in movement?

Answer 19

• Novice
  
  • More reliant on muscle force to generate movement
• Expert
  
  • takes advantage of elasticity to conserve muscle force

Question 20

What factors influence osterokinematics?

Answer 20

• Joint surface
• Tissue bulk
• Connective Tissue
• Bony limitations

Question 21

Definition of rostral

Answer 21

meaning; Towards the nose

Question 22

Conceptually:

Why do old people or those in pain at the hip lean onto the painful/joint side?

Answer 22

By shifting the center of mass over the joint we reduce the total amount of muscle force needed to contract the affected area.

Question 23

Definition of cephalad

Answer 23

meaning; Towards the head

Question 24

What are the External causes of movement?

Answer 24

• Gravity “is working against me”
• Buoyancy
• Air resistance
• Friction
• Therapist (another person)
• Theraband

Question 25

What combined actions of the foot cause supination/inversion?

Answer 25

* Plantar flexion * adduction

Question 26

What are the 5 variables that describe the displacement of a segment?

Answer 26

1. The **type** of displacement 2. the **location** in space of the displacement 3. the **direction** of the displacement 4. the **magnitude** of the displacement 5. the **rate** of change in displacement or the rate of change of velocity