Biomechanics Principles

Question 1

Mechanics

Answer 1

study of the motion of objects and forces which cause that motion

Question 2

Rigid-Body Mechanics

Answer 2

one of the branches in biomechanics in which the object being analyzed is assumed to be rigid

Question 3

Kinematics

Answer 3

branch of mechanics that describes the motion of a body; assessed by goniometer and accelerator

Question 4

Kinetics

Answer 4

branch of mechanics that describes the effect of forces and torques on the body; measured by transducer

Question 5

Moment Arm

Answer 5

perpendicular distance between an axis of rotation and the line of force

Question 6

Torque/ Moment

Answer 6

a force multiplied by Its moment arm

Question 7

Internal Force

Answer 7

push or pull produced by a structure located within the body; mostly produced by an active msucle

Question 8

Internal/ External torque

Answer 8

product of an internal/ external force and its internal/ external moment arm

Question 9

Joint reaction force

Answer 9

forces that exists at a joint, developed in reaction to net effect of internal and external forces

Question 10

Mechanical advantage

Answer 10

ration of the internal moment arm to the ecternal moment arm or of the poutput force to the input force
MA= a/b = Fb/Fa

Question 11

Movements of human body

Answer 11

moves primarily through rotations of limbs and trunk, based on interaction between internal and external torques

Question 12

Lever Function

Answer 12

1. Create a mechanical advantage (MA)
2. Magnify force (MA>1
3. Increase speed and ROM through which the end lever moves (MA<1)
4. Balance equal forces MA=1

Question 13

What does the function of a lever depend on?

Answer 13

the relative positions and sizes of the force arms

Question 14

Class 1 Lever

Answer 14

Fulcrum in the middle, MA can be greater/less/equal to 1
designed for speed and ROM if F closer to E
designed for strength when F is closer to R

Question 15

Class 2 Lever

Answer 15

resistance in the middle; MA>1
designed for strength

Question 16

Class 3 Lever

Answer 16

effort in the middle; MA>1
designed for speed and ROM

Question 17

What type of lever are most musculoskeletal levers>

Answer 17

3rd class levers

Question 18

What are Biomechanical analyses based on>

Answer 18

Static state, dynamic state, cases

Question 19

Statics

Answer 19

when there is no acceleration, the situation is described as equilibrium

Question 20

Dynamics

Answer 20

when acceleration is occurring, the system is not in equilibrium

Question 21

Torque

Answer 21

turning effect that causes the rotation about a joint