Ambulation and Functional Mobility Flashcards
What can be defined as a series of rhythmical , alternating movements of the trunk and limbs which result in the forward progression of the center of gravity?
Normal gait
Gait can also be defined as a series of controlled _____.
falls
What percent of the gait cycle is spent in stance and what percent in swing?
Stance = 60%
Swing = 40%
Describe the 4 phases of stance and during what part of the gait cycle they occur in
1) Loading Response: 0-10%
2) Mid-Stance: 10-30%
3) Terminal Stance: 30-50%
4) Preswing: 50-60%
Describe the 3 phases of swing and during what part of the gait cycle they occur in
1) Initial Swing: 60-73%
2) Med-Swing: 73-87%
3) Terminal Swing: 87-100%
What can be defined as the distance between corresponding successive points of heel contact of the opposite feet?
Step Length
What can be defined as the distance between successive points of heel contact of the same foot?
Stride Length
In normal gait what should stride length equal?
double the step length
What can be defined as the side-to-side distance between the line of the two feet?
Walking Base or Stride Width
What can be defined as the number of steps per unit time?
cadence
What is normal gait cadence?
100 – 115 steps/min
What can be defined as the distance covered by the body in unit time (m/s)?
velocity
How can you calculate average velocity?
= step length x cadence
What can be defined as the least energy consumption per unit distance?
Comfortable Walking Speed (CWS)
What is the average comfortable walking speed?
80 m/min (5 km/h or 3 mph)
With increasing walking speeds:
Stance phase ______
Swing phase ______
Double support ______
decreases
increases
decreases
What can be defined as walking without double support?
running
What happens to the stance/swing ration during running?
It reverses so that swing = 60% and stance = 40%
Where is the center of gravity located?
Midway between the hips and a few cm in front of S2
The least amount of energy is consumed if the center of gravity travels _____.
straight
At what point of the gait cycle is the COG the highest? Lowest?
midstance
double support
What is the average vertical displacement of the COG throughout the gait cycle?
5 cm
At what point of the gait cycle does the pelvis reach its lateral limit?
midstance
What is the average lateral displacement of the COG throughout the gait cycle?
5 cm
What are the 6 determinants of gait that are used to minimize excursion of the COG therefore significantly reducing energy consumption?
1) Pelvic rotation
2) Pelvic tilt
3) Knee flexion in stance phase
4) Ankle mechanism
5) Foot mechanism
6) Lateral displacement of body
Pelvic rotation is the forward rotation of the pelvis in the horizontal plane approximately _ degrees on the swing-phase side
8
Why does the pelvis rotate forward during the swing phase?
It reduces the angle of hip flexion and extension. Which in turn enables a slightly longer step-length w/o further lowering of the COG.
Pelvic tilt is described as the _ degree dip that occurs during the swing phase
5
If the dip occurs during the stance phase it is considered abnormal and called what?
Trendelenberg sign
During the stance phase there is approximately how much knee flexion?
20 degrees
Knee flexion in the middle of stance phase ____ the leg and _____ the height of the apex of the curve of the COG
shortens
reduces
The ankle mechanism that occurs during heel contact ______ the leg.
lengthens
The foot mechanism that occurs at toe-off _____ the leg as the ankle moves from DF into PF
lengthens
Both the ankle and foot mechanisms do 2 things to the COG, what are they?
- It smoothens the curve of the COG
- Reduces the lowering of the COG
What is the benefit of having a narrow walking base?
It minimizes the lateral displacement of the COG which in turn reduces muscular energy consumption
What are the 4 forces that have the most significant influence on gait?
(1) gravity
(2) muscular contraction
(3) inertia
(4) floor reaction
The force that the foot exerts on the floor due to gravity & inertia is opposed by what force?
ground reaction force