Principles 1- WK1 ( Ch 1+4)

Question 1

What is the difference between kinesiology and biomechanics ?

Answer 1

Kinesiology: kinesis ( to move), logy (study of), therefore kinesiology is the study of movement

Biomechanics: discipline that uses principles of physics to quantitatively study how forces interact within a living body.

Question 2

What is the difference between kinematics and kinetics ?

Answer 2

• Both are branches of biomechanics

Kinematics: describes the motion of a body without regard to forces or torques produced in motion, includes arthrokinematics and osteokinematics

Kinetics: the study of mechanics that describes the effect of forces on the body, includes physics principles

Question 3

Is naming the plane of motion considered part of kinetics or kinematics ?

Answer 3

Kinematics because planes of motion categorize movements without consideration of physics principles

Question 4

List 6 rotary motions and 6 translatory motions the body performs on the daily basis. What are the main differences in how these motions are performed by the body ?

Answer 4

… TBD

Question 5

How does translation differ from rotation ?

Answer 5

Translation: linear motion; all part of rigid body move parallel and in the same direction as every part of the body; rectilinear or curvilinear; m or ft

Rotation: rigid body moves in a circular path around a pivot point

Question 6

What is an axis of rotation and what is an evolute axis of rotation ?

Answer 6

-pivot point for angular motion of the body or its parts, during rotation where movement=0

• evolute AoR: a changing AoR as is typically seen in human joints

Question 7

How does active movement differ from passive movement ?

Answer 7

active movement is typically voluntary and performed by muscles; whereas passive movement is caused by an external force such as therapist moving a patients hand for them

Question 8

In which cardinal plane do the following motions occur ? lumbar flexion, shoulder abduction, hip internal rotation, knee flexion, cervical rotation, finger abduction.

Answer 8

Lumbar flexion: sagittal
shoulder abduction: coronal/frontal
hip IR: horizontal
cervical rotation: horizontal
knee flexion: sagittal
finger abduction: frontal/coronal

Question 9

In which cardinal plane does the axis of rotation lie for the following motions: shoulder ER, elbow flexion, hip abduction, ankle dorsiflexion, cervical rotation, MCP flexion

Answer 9

shoulder ER: vertical
elbow flexion: frontal
hip abduction: sagittal
ankle dorsiflexion: frontal
cervical rotation: vertical
MCP flexion: frontal

Question 10

Define degrees of freedom ?

Answer 10

The number of independent directions of movements allowed at a joint.

Question 11

How many degrees of freedom do the following joints have: Hip, Knee, Great Toe

Answer 11

Hip: multiaxial
Knee: uniaxial
Great Toe: biaxial

Question 12

Give and example of a joint that is: uniaxial, biaxial, triaxial

Answer 12

uni-: knee joint
bi-: MCP joints
tri-: shoulder

Question 13

What is the difference between osteokinematic and arthrokinematic movement ?

Answer 13

osteo-: motion of bones relative to 3 cardinal planes
arhtro-: motion occurring between articular surfaces of joints

Question 14

What is meant by “end feel” ?

Answer 14

joint’s resistance to further motion

Question 15

What is the difference between open and closed chain kinematic movements ?

Answer 15

open chain kinematics: usually distal on proximal movement; distal segment is free to move

close chain kinematics: usually proximal on distal movement; distal segment fixed

Question 16

Which movements fall under the category of arthrokinematics ?

Answer 16

Roll, Slide, Spin

Question 17

Explain the convex-concave rule.

Answer 17

• convex joint rolls one way and slides the opposite way

-if a concave joint moves across a convex surface then rolls one way and slides the same way

Question 18

Compare a close packed position to an open packed position.

Answer 18

CPP: “max congruency”; joint surfaces have most surface area of contact; ligaments and capsules taut; stable; near end range

OPP: incongruency; lax ligaments and capsules; increased accessory motions; LE LPP= flexed

Question 19

Define Force:

Answer 19

can be called a load

a push or pull that can produce, arrest, or modify movements

Question 20

Walk through the sequence of the stress strain curve defining the following points: stress, strain, toe point, elastic region, yield point, plastic region, ultimate failure point.

Answer 20

Stress: Y-Axis; Internal resistance to deformation of tissue
Strain: X-Axis; % increase in length of tissue
“Toe” Region: initial crimped tissue; before made taut
Elastic Region: increase of strain but tissue can regain shape if force is removed
Yield Point: when tissue is elongated beyond physiological range; no more resistance from tissue; strain continues
Plastic Region: strain continues; microscopic tissue failure; permanent deformation
Ultimate Failure Point: tissue tears; can no longer hold tissue

Question 21

What are viscoelasticity and creep ?

Answer 21

viscoelasticity: tissues with physical properties associated with stress strain curve that change as function of time

creep: progressive strain of a material when exposed to a load over time

Question 22

Discuss the difference between elastic and plastic deformation of the hamstrings in terms of increasing flexibility without causing tissue injury.

Answer 22

….

Question 23

What is the advantage of having 3rd class levers in the body ?

Answer 23

you can move a small load over a large distance