Biomechanics Pt. 1 (8/30a) Flashcards Preview

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Flashcards in Biomechanics Pt. 1 (8/30a) Deck (33)
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1
Q

Biomechanics

A

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)

2
Q

Kinematics

A

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

3
Q

Translational/linear motion

A

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)

4
Q

Rotational/angular motion

A

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

5
Q

Axis of rotation

A

point that remains stationary or pivot point for angular motion

6
Q

Linear kinematic measures

A

displacement (meters)

velocity (meters/second)

acceleration (meters/sec2)

7
Q

Rotational kinematic measures

A

angular displacement (degrees)

velocity (degrees/second)

acceleration (degrees/sec2)

8
Q

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

A

Both

9
Q

Center of mass (COM)

A

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

10
Q

Center of gravity (COG)

A

point at which the weight of an object is concentrated

Depends on shape and mass distribution; position dependent

11
Q

Active motion

A

any conscious or subconscious movement you do on your own

EX: lifting your knee, blinking, running, etc

12
Q

Passive motion

A

movement that an external force physically makes you do

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

13
Q

Osteokinematics

A

Describes motion of a bone relative to cardinal plane of motion

angular motion

14
Q

Frontal/coronal plane

A

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

15
Q

Sagittal plane

A

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

16
Q

Horizontal/transverse plane

A

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

17
Q

Degrees of freedom (DOF)

A

number of permitted planes of angular motion at a point

18
Q

Number of degrees of freedom

A

3 DOF = 1 for each angular plane

19
Q

Exceptions to DOF in body

A

Not all joints allow 3 DOF

Hinge joint - 1 DOF (sagittal)

Pivot joint - 1 DOF (transverse)

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

20
Q

Arthrokinematics

A

Describes motion between joint surfaces

translational motion

21
Q

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

A

convex-concave

22
Q

Joint play/Accessory joint motion

A

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

23
Q

DOF with joint play

A

Linear translational motion + angular motion

3 angular DOF + 3 linear DOF = 6 DOF

24
Q

3 motions at joint surfaces

A

Roll
Slide/Glide
Spin

25
Q

Roll (joint motion)

A

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

26
Q

Slide/glide (joint motion)

A

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

27
Q

Spin (joint motion)

A

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

28
Q

If you move the CONCAVE surface on the CONVEX surface…

A

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

29
Q

If you move the CONVEX surface on the CONCAVE surface…

A

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

30
Q

Closed packed joint position

A

best fit or most congruent position

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

31
Q

Loose/open packed joint position

A

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

32
Q

CASSS Movement Analysis

A

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?

33
Q

Which side of the body do you analyze first?

A

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