Module 1

Question 1

kinematics

Answer 1

describes motion (translation and rotation) of body without regard of forces or torque

Question 2

translation movement

Answer 2

linear motion which all parts of rigid body move parallel and same direction of every other part of body
- can be straight line or curved

Question 3

rotational motion

Answer 3

rigid body moves in circular path around some pivot point

Question 4

what is the axis of rotatio

Answer 4

motion of rotating body is zero

Question 5

what are the variables related to kinematics

Answer 5

position, velocity, and acceleration

Question 6

define a joint

Answer 6

two or more bony or limb segments

Question 7

what type of bone rotation is common in the upper extremity

Answer 7

distal-on-proximal segment kinematics

Question 8

the lower extremity performs what type of segment kinematics

Answer 8

proximal-on-distal AND distal-on-proximal

Question 9

define arthrokinematics

Answer 9

motion between articular surfaces of joints

Question 10

what are the fundamental movements between curved joint surfaces

Answer 10

roll, slide, spin

Question 11

spinning of one articular surface against another is the primary motion for what axis

Answer 11

longitudinal (transverse plane of motion)

Question 12

during convex-onconcave movement the convex surface rolls and slide in what direction

Answer 12

opposite directions

Question 13

during concave-on-convex movement the concave portion rolls and slides in what direction

Answer 13

similar directions

Question 14

define closed-packed position

Answer 14

most ligaments and capsular parts are taut and has maximal congruency

Question 15

joints are usually most congruent at what point of ROM

Answer 15

near end range of motion

Question 16

joints are generally least congruent at what point of motion

Answer 16

midrange

Question 17

define kinetics

Answer 17

effect of forces on the body

Question 18

what is a force

Answer 18

push or pull that can produce, arrest, or modify movement

Question 19

define strain

Answer 19

percent increase in a tissue’s stretched length relative to its original preexperimental length

Question 19

define creep

Answer 19

progressive strain when exposed to a constant load over time

Question 20

what are passive forces

Answer 20

caused by tension in stretched CT, ligaments, and joint capsules

Question 21

what are active forces

Answer 21

generated by stimulated muscle (doesn’t have to be under volitional control)

Question 22

define moment arm

Answer 22

perpendicular distance from axis of rotation of joint to the force

Question 23

even when muscle force lacks a moment arm (so no torque is generated) why is it still important

Answer 23

source of stability and sensory information to the joint

Question 24

define isometric muscle force

Answer 24

internal torque = external torque so muscle stays the same length

Question 25

define concentric activation

Answer 25

internal torque exceeds opposing external torque creating a rotation of the joint in direction of the pull of activated muscle

Question 26

define muscle action

Answer 26

potential for a muscle to cause a torque in a particular rotation direction and plane

Question 27

define muscular force-couple

Answer 27

two or more muscles produce force in different linear directions but cause torques in the same rotary direction

Question 28

define a lever

Answer 28

rigid rod suspended across a pivot point

Question 29

example of first class levers in the body

Answer 29

head and neck extensor muscles - axis of rotation positioned between opposing forces

Question 30

in first class levers are internal and external forces in the same or different linear direction? what about torques

Answer 30

same linear direction BUT different rotary directions for torque

Question 31

what are second class levers? example in body

Answer 31

axis of rotation is located at one end of the bone - internal forces produce greater leverage than external force - very rare in body but calf muscles use this to stand on tippy toes

Question 32

define third class levers, examples?

Answer 32

axis at the other end of bone compared to 2nd class. external force has greater leverage than muscle force. Most common lever in musculoskeletal system

Question 33

define mechanical advantage

Answer 33

ratio of internal moment arm to external moment arm

Question 34

in first class levers what can the MA equal

Answer 34

less than, equal to, or greater than 1

Question 35

in 2nd class levers what does the MA equal

Answer 35

ALWAYS greater than 1. To balance torques the internal force must be less than the external force

Question 36

in 3rd class levers what is MA equal to

Answer 36

ALWAYS less than 1. thus to balance torque equilibrium internal forces have to be GREATER than external forces

Question 37

define joint

Answer 37

junction or pivot between two or more bones