Intro to Biomechanics (anatomical planes, axes)

Question 1

how do biomechanics concepts inform PTs in their daily practice? (5)

Answer 1

force application (manual therapy, muscle tests)
lever arms (exercise progression)
muscle mechanics (length-tension, force-velocity)
tissue properties (tendon, bone, cartilage)
muscle force requirements for tasks/exercises

Question 2

how do biomechanics concepts inform PTs as researchers? (5)

Answer 2

comparisons between healthy and disorder/disease of interest
compare effectiveness of interventions
most efficient way to assess, strengthen, progress
mechanisms of injury
assistive devices (robotics)

Question 3

biomechanics helps us to objectively measure… (4)

Answer 3

strength gains
movement pattern improvements
muscle activation patterns
motor control

Question 4

axis and coordinate systems

• purpose
• International Society of Biomechanics (ISB) standard for 3-dimensional analysis

Answer 4

purpose
-must use to indicate directionality
ISB
-‘y’ is positive upward (vertical)
-‘x’ is positive anteriorly (direction of forward progression for gait; anteroposterior)
-‘z’ is positive to the person’s right (mediolateral)

Question 5

for 2-d analysis, use…

Answer 5

xy convention

Question 6

anatomical planes (3)

Answer 6

frontal (coronal)
transverse (horizontal)
sagittal

Question 7

frontal plane

• formed by which axes
• motion occurs in which plane

Answer 7

formed by y (vertical) and z (mediolateral) axes

rotation occurs about the x (anteroposterior) axis

Question 8

transverse plane

• formed by which axes
• motion occurs in which plane

Answer 8

formed by x and z axes

rotation occurs about y axis

Question 9

sagittal plane

• formed by which axes
• motion occurs in which plane

Answer 9

formed by x and y axes

rotation occurs about the z axis

Question 10

kinematics vs kinetics

Answer 10

kinematics
-description of motion
-displacement, velocity, acceleration
kinetics
-description of forces
-forces, moments (torque)

Question 11

linear kinematics

• what type of movement
• what is displacement
• what is velocity
• what is acceleration

Answer 11

movement type
-translation
displacement
-change in distance
velocity
-change in distance/change in time
acceleration
-change in velocity/change in time

Question 12

angular kinematics

• what type of movement
• what is angular displacement
• what is angular velocity
• what is angular acceleration

Answer 12

movement type
-rotation
angular displacement
-change in angle (theta)
-must define CW vs. CCW
angular velocity
-change in angular displacement/change in time
angular acceleration
-change in angular velocity/change in time
-w (omega) = theta/time
-A (alpha) = omega/time

Question 13

human movement is nearly always a combination of…

Answer 13

linear and angular motion

Question 14

kinetics - linear

• force definition
• force =…
• what are external forces
• -examples
• what are internal forces
• -examples

Answer 14

force
-a push or pull of one object on another
F = ma = kg*m/s(squared) = Newton
external forces
-forces acting on the body
-gravity, weight held in the hand, another object
internal forces
-forces acting inside the body
-muscle force, passive constraints (ligaments)

Question 15

kinetics - rotational

• moment (torque) definition
• M =
• Ma (or d) =

Answer 15

moment
-the rotational effect of a force about an axis of rotation
M = F (force) * moment arm
Ma (or d)
-perpendicular distance between line of action of the force and the axis of rotation

Question 16

qualitative vs. quantitative

Answer 16

qualitative
-a description of movement without the use of numbers
quantitative
-a description of movement that uses numbers

Question 17

examples of qualitative measurements that PTs take

Answer 17

strong/weak
smooth/jerky
good/poor control
hyper/hopo-mobile
excessive/restricted
fast/slow

Question 18

examples of quatitative measurements that PTs take

Answer 18

goniometry
manual muscle testing
spasticity scales
dynamometry
electromyography
timing