Exam 1 Flashcards
MASTERY (90 cards)
1
Q
what is biomechanics?
A
study of actions of forces and mechanical aspects of living organisms.
2
Q
sub-branches of biomechanics
A
Kinematics and kinetics
3
Q
what is kinematics?
A
study of the appearance or description of motion.
4
Q
What is kinetics
A
Study of the actions of the forces.
5
Q
Qualitative
A
features or aspects of something
6
Q
Quantitative
A
data of something (numbers)
7
Q
3 anatomical reference axis
A
longitudinal, anteroposterior, mediolateral
8
Q
longitudinal axis
A
directed vertically and around which translations in the transverse plane occur.
9
Q
anteroposterior axis
A
directed along the sagittal plane and around which rotations in the frontal plane occur.
10
Q
mediolateral axis
A
directed along the frontal plane and around which rotations in the sagittal plane occur.
11
Q
3 anatomical reference planes
A
sagittal, frontal/coronal, transverse
12
Q
sagittal plane
A
splits body into left and right partitions
13
Q
frontal or coronal plane
A
splits the body into front and back partitions
14
Q
transverse plane
A
splits the body into top and bottom partitions
15
Q
forms of motion
A
linear/translational, rectilinear, curvilinear, angular/rotational, general
16
Q
linear/translational motion
A
motion along a line (axis)
17
Q
rectilinear motion
A
along a straight line
18
Q
curvilinear motion
A
along a curved line
19
Q
angular/rotational motion
A
motion around an axis & in a plane
20
Q
general motion
A
a combination of translational and angular motion
21
Q
what is mass?
A
quantity of matter composing a body
22
Q
what is inertia?
A
tendency to resist change in state of motion.
23
Q
what is force?
A
a push or pull
24
Q
what is weight
A
attractive force that the earth exerts on a body.
25
what is free body diagram?
a diagram showing a vector representation of all forces acting on a defined system.
26
what is net force?
single resultant force derived from the vector composition of all the acting forces
27
what is a torque (aka moment)
rotary effect of a force, the angular equivalent of force (aka moment of force)
28
what is vector composition?
process of determining a single vector from two or more vectors.
29
what is vector resolution?
operation that replaces a single vector with two perpendicular vectors such that the vector composition of the two perpendicular vectors yields the original vector.
30
structure of bone
dynamic, living tissue
31
2 important mechanical functions of bone
1. rigid framework providing support & protection
2. system of levers to allow motion
32
composition and structure of bone. (major building blocks)
- calcium carbonate
- calcium phosphate
- collagen
- water(25-30% weight of bone)
33
what contributes to the bones stiffness and compressive strength
calcium carbonate
34
what contributes to flexibility and tensile strength of bones.
collagen
35
what is the effect of aging on collagen in bone?
reduced flexibility and strength
36
types of bone
cortical bone, trabecular (cancellous) bone
37
cortical bone
compact mineralized bone with low porosity; found in shafts of long bones
38
trabecular (cancellous) bone
less compact bone with high porosity; found in ends of long bones and the vertebrae
39
types of bones
axial skeleton, appendicular skeleton
40
axial skeleton
skull, vertebrae, sternum, ribs
41
appendicular skeleton
bones composing the body appendages (varying shapes: short, flat, irregular, and long)
42
what are bone cells called
osteocytes
43
how do bones grow in length?
the epiphyses/epiphyseal plates; growth centers where new bone cells are produced until late adolescents or early adulthood. Then they close
44
How do bones grow in circumference?
- the inner layer of the periosteum (double-layered membrane covering bone) builds concentric layers of new bone on top of existing ones.
- specialized cells called osteoblasts build new bone tissue and osteoclasts resorb bone tissue
45
how do bones respond to training?
hypertrophy: just like muscle, bones respond to certain kinds of training
46
Wolff's law
the densities, and to a lesser extent, the sizes and shapes of bones are determined by a magnitude and direction of the acting forces.
47
How is Wolff's law carried out?
osteoblasts and osteoclasts are continually resorbing bone, respectively
(increased or decreased leads to a predominance of osteoblast or osteoclast activity, respecitvely)
48
what kind of activity tends to promote bone density?
weight bearing exercise.
49
what tends to diminish bone density?
lack of weight bearing exercise, time in the water, bed rest, traveling in space (outside of gravitational field)
50
what is osteoporosis?
a disorder involving decreased bone mass and strength with pain and one or more fractures resulting from daily activity.
51
who is affected by osteoporosis? Type 1
postmenopausal - affects about 40% of women after age 50
52
who is affected by osteoporosis? Type 2
age-associated - osteoporosis affects most women and men after age 70
53
female athlete triad
osteoporosis, disordered eating, and amenorrhea
54
3 basic types of joints
immovable, slightly moveable, freely moveable
55
immovable other name
synarthroses(sutures)
56
slightly moveable other name
amphiarthroses(symphyses)
57
freely moveable joints (diarthroses or synovial) classification
- articular cartilage: a protective layer of dense white connective tissue covering the articulating bone surfaces
- articular capsule: a double-layered membrane that surrounds the joint
- synovial fluid: a clear, slightly yellow liquid that provides lubrication inside the articular capsule
- associated bursae: small capsules filled with synovial fluids that cushion the structures they separate
57
freely moveable other name
diarthroses or synovial
58
classification of diarthroses or synovial joints:
- gliding
- hinge
- pivot
- condyloid
- saddle
- ball and socket
(understand the translations and rotations of these)
59
what are the functions of articular cartilage?
- spreads over a wide area, reducing contact stress
- provides protective lubrication that minimizes friction and mechanical wear
60
what is articular fiborcartilage?
soft tissue discs or menisci that intervene between articulating bones
61
what are the possible functions for articular fibrocartilage?
- disrupting loads
- improving the fit of articulations
- limiting slip
- protection
- lubrication
- absorbing shock
62
what are articular connective tissues?
tendons(muscle to bone) and ligaments(bone to bone)
63
what is joint stability?
ability of a joint to resist abnormal displacement of articulating bones
64
what factors increase joint stability?
- a closely reciprocating match of the articulating bone surfaces
- a strong array of ligaments and muscle tendons crossing the joint
- absence of muscle fatigue
65
what is joint flexibility?
description of the relative ranges of motion allowed at a joint in different directions
66
what is range of motion (ROM)?
The angle through which a joint moves from anatomical reference position to the extreme limit of segment motion in a particular direction
67
how is ROM measured
from an anatomical position (zero)
68
what is linear displacement?
- change in location(directed distance from initial to final location)
- units: cm, m, km
68
what factors influence joint flexibility?
- intervening bony or muscle tissue or fat at the end of the ROM
- tightness/laxity in the muscle and collagenous tissue crossing a joint
- muscle fatigue
68
how do we define kinematics?
the pattern or sequencing of movement with respect to time
69
speed =
distance/time
70
what is linear speed?
distance covered over time taken
70
scalars vs. vectors
scalars have magnitude, vectors have magnitude and direction
71
what is linear velocity?
rate of change in location?
72
velocity =
displacement/time
73
what is acceleration?
rate of change in linear velocity
- can be 0, -, +
73
acceleration =
change in velocity/time
73
what is a projectile?
- an object projected into the air
- no additional force generation
- analyzed based on two components (horizontal and vertical)
73
factors influencing projectile trajectory
projection angle, projection speed, relative height of projection
74
projection angle
the direction of projection with respect to the horizontal
75
projection speed
magnitude
76
relative height of projection
initial height relative to landing
77
what is relative angle?
angle at a joint formed between the longitudinal axes of adjacent body segments (AKA joint angle. the straight, fully extended position at a joint is regarded as zero)
78
what is an absolute angle?
angular orientation of a body segment with respect to a fixed line of reference.(reference lines are usually vertical or horizontal)
79
what is angular displacement?
- change in angular position around an axis
- the directed angular distance from initial to final angular position
- the vector equivalent of angular distance (measured in degrees)
80
what is angular velocity?
- rate of change in angular position
81
angular velocity =
change in ang. displacement/ time
- measured in degrees / s
82
what is angular acceleration?
- the rate of change in angular velocity
83
angular acceleration =
change in ang. velocity / time
- measured in deg/s^2
