Week 1 Flashcards
What does a moment of inertia mean?
moment of inertia is the ability to move an object in an angular motion
Explain what happens to control as degrees of freedom increase at a given joint.
The more freedom the more muscles you need to control it.
What combined actions of the foot cause pronation or eversion?
- Dorsi Flexion
- Abduction
Definition of Kinematics
Branch of biomechanics that deals with the description of movement without regard to causes of movement
Instantaneous axis of rotation
The change in the axis positioning in relation to total movement.
What is the equation for the moment of inertia?
Explain what is meant by “gravity eliminated” action in regards to patient care.
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.
Conceptualize movement!
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.
What happens to the angular momentum of a fixed distance system if the mass is increased?
If we increase the mass of an object we increase the total inertia of that system thereby increasing angular momentum.
What is a distraction force?
This is the net force that moves a boney segment away from its adjacent segment.
Definition of Statics
Branch of mechanics that deals with forces in the absence of changes in motion.
What are the internal causes of movement?
- Muscle Contraction
- Elasticity
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?
As we move closer it becomes easier.
What is the center of pressure?
This is the point in a system where force is applied.
What is the equation for angular momentum?
Definition of Kinetics
Branch of biomechanics that deals with the causes of movement
Definition of Dynamics
Branch of mechanics that deals with the effect that forces have on the motion of objects.
How do we determine linear velocity?
As we transition from novice to expert what happens to the relationship between muscle contraction and elasticity in movement?
- Novice
- More reliant on muscle force to generate movement
- Expert
- takes advantage of elasticity to conserve muscle force
What factors influence osterokinematics?
- Joint surface
- Tissue bulk
- Connective Tissue
- Bony limitations
Definition of rostral
meaning; Towards the nose
Conceptually:
Why do old people or those in pain at the hip lean onto the painful/joint side?
By shifting the center of mass over the joint we reduce the total amount of muscle force needed to contract the affected area.
Definition of cephalad
meaning; Towards the head
What are the External causes of movement?
- Gravity “is working against me”
- Buoyancy
- Air resistance
- Friction
- Therapist (another person)
- Theraband
What combined actions of the foot cause supination/inversion?
- Plantar flexion
- adduction
What are the 5 variables that describe the displacement of a segment?
- The type of displacement
- the location in space of the displacement
- the direction of the displacement
- the magnitude of the displacement
- the rate of change in displacement or the rate of change of velocity
