Lecture 2 Biomechanical Terminology Gait Flashcards
What is biomechanics
The study of the structure and function of biological systems by means of methods of mechanics
Kinematics
The study of motion (without regard to the forces that cause it)
Kinetics
The study of forces
Quantitative analysis
Numerical evaluation of motion based on measurement
Qualitative analysis
Non-numerical evaluation of motion based on observation
Statics
Evaluation of objects in a state of equilibrium
- objects are at rest or moving at a constant velocity
Dynamics
Evaluation of objects that are not in a state of equilibrium
- objects are accelerating (speeding up or slowing down)
Scalers
Can be described fully by their magnitude
- distance
- speed
- mass
- volume
- energy
Vectors
To fully describe a vector, its magnitude and direction is required
- displacement
- velocity
- acceleration
- force
What can be linear motion
Straight or curved motion such as that all parts of an object move the same distance in an equal amount of time
Also known as translation or translational motion
Angular motion
Motion about an axis of rotation such as regions of a segment rotating about that axis do not move through the same distance in an equal amount of time
What is gait
A particular pattern of footfalls that are used in locomotion (walk and run)
Gait cycle events
Stance phase 60% of stride
Swing phase 40% of stride
Single support 80% of stride
Double support 20% of stride
What is a step
The process of moving one limb forward
What is a stride
The process of making one step with each foot
Stride time
The time it takes to complete one stride
Stride length
Distance between heel strikes of the same foot
1 stride = …
2 steps assuming symmetry
Stride velocity = …
Stride length (m) / stride time (s)
Stride velocity is a vector and does not include turns (will always be equal to or less than walking speed)
Walking speed = …
Distance (m) / time (s)
Walking speed is a scalar and includes turns (greater than stride velocity)
Stride cadence = …
1 / stride time (s)
What is the difference between a walk and a run?
Walk
- Alternating pattern of one foot - two feet
(Always at least one foot in contact)
Run
- Alternating pattern of one foot - no feet
(An airborne phase between contacts)
