biomechanics

Question 1

Recognized as the first true biomechanist
• First to study anatomy in the context of mechanics
• Analyzed muscle forces as acting along lines
connecting origins and insertions and studied joint
function

Answer 1

Leonardo da Vinci

Question 2

• Interested in the strength of bones
• Noted that animals’ with large mass bones increase
in girth
• Theorized adapted to loadbearing
• Suggested that bones are hollow for this affords
maximum strength with minimum weight

Answer 2

Galileo Galilei

Question 3

Studied walking, running, jumping, and even the piston
action of the heart within a mechanical framework
• Determined
• Position of the center of gravity
• Calculate and measured inspired and expired air
volumes
• Showed that inspiration is muscle-driven and expiration
is due to tissue elasticity

Answer 3

Giovanni Alfonso Borelli

Question 4

Biomechanics describe the

Answer 4

relationship

between structure and function

Question 5

Machines function in four ways

Answer 5

Balance multiple forces
2. Enhance force in an attempt to reduce total force
needed to overcome a resistance
3. Enhance range of motion & speed of movement so
that resistance may be moved further or faster than applied force
4. Alter resulting direction of the applied force

Question 6

3 types of “machines” in producing movement

Answer 6

Levers (most common)
• Torque and length
2. Wheel-axles
• Function essentially as a form of a lever
3. Pulleys
• Single pulleys function to change effective
direction of force application

Question 7

which class level is most common in human body?

Answer 7

Third-Class Levers

Question 8

Joint motion is resultant of

Answer 8

• A muscle contraction
  • Drawing a distal segment more proximal
  • The distal segment will rotate about the
  center of the joint

Question 9

relaxation def.

Answer 9

As the matrix of the segment reaches equilibrium,
or a neutral position, the load necessary to
maintain the length of the segment will decrease

Question 10

The relative motions of joints surfaces may include

Answer 10

• Gliding
• Rolling
• Spin
• Compress
• Distract

Question 11

Strength def., what is it dependent on, what does it produce? center of rotation at?

Answer 11

Amount of force needed to contract a muscle
• Dependent on degree of resistance (a.k.a. load)
experienced
• Produces a rotation (torque)
• The center of rotation, fulcrum or axis, is created at the
point of muscle insertion

Question 12

moment def.,

Answer 12

The force being applied plus the moment arm
• Moment arm = the distance from the center of the
joint to where the contracting muscle is attached
• i.e. (force x distance)

Question 13

known as the stiffness of the structure

Answer 13

The amount of force necessary to bend an object

Question 14

rapid stretch vs. slower stretch in terms of resistance

Answer 14

• Rapid stretch will be met with increased resistance
• The faster you squeeze the less water you get out
Biomechanics Principles
• Slower stretch will be met with less resistance
• The slower, longer the squeeze, the more
complete expression of fluid from within the
matrix
slower stretch known as CREEP

Question 15

types of stress

Answer 15

Force can act upon a structure from various orientations
• Tension acts to stretch
• Compression
• Shearing acts parallel to the surface
• Bending acts to fold about an axis
• Torsion twists about an axis

Question 16

mechanical loading can cause

Answer 16

tissue deformation.

load = sum of all stresses

Question 17

external applied forces

Answer 17

Produced from outside the body & originate
from gravity, inertia, or direct contact
• Ground reaction forces (GRF)
• The force exerted by the ground on a
body in contact with the ground

Question 18

Internal applied forces

Answer 18

• Muscular, joint and skeletal actions of the

body during the execution of a given task

Question 19

vertical load (internal applied force) def.

Answer 19

Summative weight transmitted
through the kinetic chain to the
ground

Question 20

• Force that results from the resistance
between surfaces of two objects from
moving upon one another

Answer 20

friction

Question 21

Only muscles can actively generate
internal force, but tension in tendons,
connective tissues, ligaments, and
joints capsules may generate

Answer 21

passive internal forces

Question 22

The magnitude of the force applied on the bone known as

Answer 22

strain

Question 23

The force applied to the insertion or the muscle at the bone results in a

Answer 23

compensatory change in the shape, or deformation, of the bone

Question 24

balance def.

Answer 24

ability to control equilibrium, either static or dynamic

Question 25

equilibrium def., static/ dynamic

Answer 25

State of zero acceleration where there is no change in the speed or direction of the body • Static equilibrium - body is at rest or completely motionless • Dynamic equilibrium - all applied & inertial forces acting on the moving body are in balance, resulting in movement with unchanging speed or direction

Question 26

stability def.

Answer 26

``` The resistance to a • Change in the body's acceleration • Disturbance of the body's equilibrium • To control equilibrium & achieve balance, stability needs to be maximized ```

Question 27

field of biomechanics: Description of motion and includes consideration of time, displacement, velocity, acceleration, and space factors of a system‘s motion

Answer 27

kinematics

Question 28

field of biomechanics: • Study of forces associated with the motion of a body

Answer 28

kinetics [branch of dynamic]

Question 29

field of biomec.: Study of systems in motion with acceleration • A system in acceleration is unbalanced due to unequal forces acting on the body

Answer 29

dynamic [branch of dynamic]

Question 30

field of biomech.: • Study of systems that are in a constant state of motion, whether at rest with no motion or moving at a constant velocity without acceleration • Statics involves all forces acting on the body being in balance resulting in the body being in equilibrium

Answer 30

Static

Question 31

Who defined the concept of “center of gravity”? a) Andrew Taylor Still b) Galileo Galilei c) Giovanni Alfonso Borelli d) John J. Dougherty e) Leonardo da Vinci

Answer 31

Giovanni Alfonso Borelli

Question 32

• Stress through the joint during movement results in a reciprocal reaction by the structures within that joint (Joint reaction force) This reaction is in direct response to which of the following contributing factors: 1. Moments 2. Load 3. Elasticity 4. A & B 5. A, B & C

Answer 32

Moments, load and elasticity!

Question 33

``` Which of the following applies a stress to the joint during movement? a) Anatomical joint lever b) Cumulative load c) Joint reaction force d) Tissue deformation ```

Answer 33

c) Joint reaction force

Question 34

Deformation can result in loss of: a) Range of motion b) Relaxation c) Resiliency d) Viscosity e) All of the above

Answer 34

all of the above

Question 35

A slow stretch resulting in more complete expression | of fluid from within the matrix is know as:

Answer 35

a) Creep b) Force c) Friction d) Strain e) Stress

Question 36

• Three primary joint types

Answer 36

* Fibrous * Cartilaginous * Synovial

Question 37

Consistent repetitive stress can cause an alteration to the structure in the form of:

Answer 37

- Failure • Deformation • Adaptation

Question 38

Pain may present as a result on compensatory mechanism and not original injury e.g. in

Answer 38

Viscerosomatic Dysfunction

Question 39

Study of biological systems, human joints

Answer 39

biotribology

Question 40

2 classifications of biomaterials, examples, types of deformation, how they analyzed

Answer 40

``` Hard • Bone • Undergo mechanical deformation • May be analyzed with the theory of linear elasticity 2. Soft tissues • Usually undergo large deformations • Cartilage • Tendon • Muscle • Skin ```

Question 41

Wolff’s law

Answer 41

``` • Bone is increased where needed and reabsorbed where it is not • Increased density/hypertrophy related to increase stresses • Decreased – condition of disuse, aging ```

Question 42

Cartilage - effect of trauma, abnormal wear? capacity to regenerate? repeated high stresses can lead to??

Answer 42

``` Trauma or abnormal wear leads to structural disruption of matrix • Loses elasticity therefore increases stiffness • Limited capacity to regenerate or repair • With repeated high stresses can lead to development of degenerative joint disease ```

Question 43

ligaments and tendons - effect of increased stress? reduced stres?

Answer 43

``` Become stronger and stiffer with increased stress • Number and quality of collagen cross-links increase • Physical training • Become weaker and less stiff with a reduction of stress • Loss of collagen • Lower deformation to fail • Immobilization • Aging ```

Question 44

SAID principle of skeletal muscle

Answer 44

Specific Adaptation | to Imposed Demands

Question 45

skeletal muscle - hypertrophy? atrophy?

Answer 45

• S.A.I.D. Principle • Remodels according to the stresses placed upon it • Hypertrophy with physical training results from increased cross section of fibers • Atrophy results from disuse or functional alteration of nerve stimulus to the muscle

Question 46

Repeated application of stresses can result in accumulated breakdown of the structure • This is referred to as

Answer 46

fatigue

Question 47

Chronic Somatic Dysfunction Characteristics

Answer 47

Fibrosis 2. Contracture 3. Skin is thin, dry, cool 4. Muscles may feel fibrotic

Question 48

body's Three sub-segmented “Units”

Answer 48

* Core * Shoulder Girdle * Pelvic Girdle

Question 49

``` pelvic tilts in lordotic back flat back swayback balanced ```

Answer 49

lordotic - anterior flat - posterior swayback - forward balanced - neutral

Question 50

6 things in an OSE

Answer 50

``` . Gait and station (posture) 2. Anterior and Posterior Spinal Curve Scoliosis 3. TART Findings Tenderness Asymmetry Restriction of motion Tissue texture changes 4. Inspection 5. Percussion 6. Palpation • Note any misalignment, asymmetry, crepitation, defects, tenderness, masses or effusions ```