Biomechanics Pt. 1 (8/30a)

Question 1

Biomechanics

Answer 1

Uses principles of engineering to model human movement

“The study of structure and function of biological systems by the means of the methods of mechanics” (Herbert Hatze 1974)

Question 2

Kinematics

Answer 2

refers to the description of motion of a body without reference to the forces that caused the motion of the body

AKA describes motion only

Question 3

Translational/linear motion

Answer 3

all points on rigid body in the same direction and same distance

EX: displacement of the body’s center of mass (approximately just anterior to sacrum in pelvis)

Question 4

Rotational/angular motion

Answer 4

all points on rigid body move in circular path around pivot point

Question 5

Axis of rotation

Answer 5

point that remains stationary or pivot point for angular motion

Question 6

Linear kinematic measures

Answer 6

displacement (meters)

velocity (meters/second)

acceleration (meters/sec2)

Question 7

Rotational kinematic measures

Answer 7

angular displacement (degrees)

velocity (degrees/second)

acceleration (degrees/sec2)

Question 8

Do joints in the human body rotate, translate, or both?

Answer 8

Both

Question 9

Center of mass (COM)

Answer 9

the balance point within a body, the point where gravity is assumed to act (center of gravity)

Question 10

Center of gravity (COG)

Answer 10

point at which the weight of an object is concentrated

Depends on shape and mass distribution; position dependent

Question 11

Active motion

Answer 11

any conscious or subconscious movement you do on your own

EX: lifting your knee, blinking, running, etc

Question 12

Passive motion

Answer 12

movement that an external force physically makes you do

EX: a PT moving your knee into flexion to check ROM

Question 13

Osteokinematics

Answer 13

Describes motion of a bone relative to cardinal plane of motion

angular motion

Question 14

Frontal/coronal plane

Answer 14

PLANE: frontal/coronal
MOVEMENT: abduction/adduction
AXIS: anterior/posterior axis

Question 15

Sagittal plane

Answer 15

PLANE: sagittal
MOVEMENT: flexion/extension
AXIS: medial/lateral axis

Question 16

Horizontal/transverse plane

Answer 16

PLANE: horizontal/transverse
MOVEMENT: external/internal rotation
AXIS: longitudinal/vertical axis

Question 17

Degrees of freedom (DOF)

Answer 17

number of permitted planes of angular motion at a point

Question 18

Number of degrees of freedom

Answer 18

3 DOF = 1 for each angular plane

Question 19

Exceptions to DOF in body

Answer 19

Not all joints allow 3 DOF

Hinge joint - 1 DOF (sagittal)

Pivot joint - 1 DOF (transverse)

Ball & socket joint - 3 DOF (frontal, sagittal, transverse)

Question 20

Arthrokinematics

Answer 20

Describes motion between joint surfaces

translational motion

Question 21

Most joints have at least a slightly curved shape, which creates a ____-____ relationship between surfaces

Answer 21

convex-concave

Question 22

Joint play/Accessory joint motion

Answer 22

Translation motion arises from active muscles and natural laxity/looseness of a joint

Question 23

DOF with joint play

Answer 23

Linear translational motion + angular motion

3 angular DOF + 3 linear DOF = 6 DOF

Question 24

3 motions at joint surfaces

Answer 24

Roll
Slide/Glide
Spin

Question 25

Roll (joint motion)

Answer 25

multiple points along a rotating articular surface contact multiple points on the other articular surface

Question 26

Slide/glide (joint motion)

Answer 26

a single point on one articular surface contacts multiple points on another articular surface

Question 27

Spin (joint motion)

Answer 27

a single point on one articular surface rotates on a single point on another articular surface

Question 28

If you move the CONCAVE surface on the CONVEX surface…

Answer 28

the arthrokinematic motion between the surfaces will occur in the SAME direction as the osteokinematic motion

Question 29

If you move the CONVEX surface on the CONCAVE surface…

Answer 29

the arthrokinematic motion between the surfaces will occur in the OPPOSITE direction as the osteokinematic motion

Question 30

Closed packed joint position

Answer 30

best fit or most congruent position

Closed packed ligaments usually taut, motion between joint surfaces is minimal, more contact area, less space in joint

Question 31

Loose/open packed joint position

Answer 31

resting position

Open packed ligaments are loose, can be a lot of joint play, often mid-range of motion, less contact area, more space in joint

Open packed position can accommodate joint swelling, fluid buildup, injury

Question 32

CASSS Movement Analysis

Answer 32

Control - how smooth?

Amount - how much?

Speed - how long does it take to do?

Symmetry - is it the same as the other side?

Symptom - does it hurt or is it bothersome?

Question 33

Which side of the body do you analyze first?

Answer 33

The unimpaired side to create baseline/understand what normal movement is for patient