Angular Kinematics

Question 1

Angular Motion

Answer 1

Motion about an axis of rotation

Question 2

Axis of Rotation

Answer 2

Imaginary line perpendicular to the plane of rotation passing through

Question 3

Joint Angle

Answer 3

Angle between anatomical position (0 degrees) and the position of the body segment that has moved

Question 4

Relative Angle

Answer 4

Joint angle between 2 adjacent segments.

Question 5

Absolute Angle

Answer 5

Angle between a body segment and either horizontal or vertical

Question 6

Goniometer

Answer 6

Hand-operated tool used for measuring the angle present at a joint

Question 7

Range of Motion

Answer 7

The angle through which a joint moves from anatomical position to the extreme limit of segment motion in a particular direction (angular displacement)

Question 8

Angular Distance

Answer 8

• Scalar quantity
• Total angular change
• Units: deg, º, rad, rev

Question 9

Angular Displacement

Answer 9

• Vector quantity
• Change in angular position.
• Formula: θ = angle2 - angle1

Question 10

Radian

Answer 10

• Unit of angular measure used in angular-linear kinematic quantity conversions
• 57.3 degree

Question 11

Angular Speed

Answer 11

• σ (sigma)
• Scalar quantity.
• angular distance/change in time.
• σ = φ/t
• φ = angular distance

Question 12

Angular Velocity

Answer 12

• Rate of change in angular position
• Change in angular position/change in time
• ω (omega)
• ω = θ/t
• ω = θ2 - θ1/t2 - t1

Question 13

Angular Acceleration

Answer 13

• Rate of change in angular velocity
• α (alpha)
• Change in angular velocity/change in time
• The angular acceleration may be positive, negative, or zero (deg/s², rad/s²).
• α = (ω2 - ω1) / (t2 - t1)
• α = Δω / Δt

Question 14

Right Hand Rule

Answer 14

• Procedure for identifying the direction of an angular motion vector
• Fingers of the right hand are curled in the direction of an angular motion
• Thumb points in the direction of the resultant vector

Question 15

Angular and Linear Distance Conversion

Answer 15

• l = rφ
• l is linear distance
• r is radius of rotation
• φ (phi) is angular distance

Question 16

Angular and Linear Displacement Conversion

Answer 16

• d = rθ
• d is linear displacement
• r is radius of rotation
• θ is angular displacement

Question 17

Angular and Linear Speed Conversion

Answer 17

• s = rσ
• s is linear speed
• r is radius of rotation
• σ (sigma) is angular speed

Question 18

Angular and Linear Velocity Conversion

Answer 18

• v = rω
• v is linear velocity
• r is radius of rotation
• ω (omega) is angular velocity

Question 19

Angular and Linear Acceleration

Answer 19

Angular acceleration may be resolved into 2 perpendicular linear acceleration components:

• Tangential acceleration
• Radial acceleration

Question 20

Tangential Acceleration

Answer 20

• Component of acceleration of a body in angular motion directed along a tangent to the path of motion
• Represents change in linear speed
• at = rα

Question 21

Radial Acceleration

Answer 21

• Component of acceleration of a body in angular motion directed toward the center of curvature
• Represents change in direction
• ar = v^2/r