Gait Phases Flashcards
What is human walking?
A series of controlled falls; forward progression of the body w/one foot always on the ground.
What is a Gait Cycle?
The time from Initial Contact (IC) on the same foot, including both stance and swing phase.
Normal Adult: ~1sec (0% - 100% GC)
What are the functional tasks of Gait Cycle?
- Weight Acceptance
- Single Limb Support
- Swing Limb Advancement
Weight Acceptance is:
The smooth transfer of body weight to lead or “reaching’ limb.
Requires: shock absorption, stability & forward progression.
Occurs in IC, LR
Advancing body weight over single limb requires:
Stabilty & Forward progression
Single Limb Support (MSt, TSt)
Swing Limb Advancement consists of:
PSw, ISw, MSw, TSw
Preparing and advancing limb through swing for foot clearance & limb advancement.
What is mEFAP?
modified Emory Functional Ambulation Profile
Outcome measure to assess gait.
List Temporal Spatial Norms:
- Walking Speed
- Cadence
- Temporal Data: Stance, swing & stride time
- Spatial Data: Step & stride length, step width
Step & Stride Length = Sagittal Plane; Step Width = Coronal Plane
What is Walking Speed (Velocity)?
Walking Speed = Distance/Time
also: WS = stride length x 1/2 cadence
The distance traversed during a specified time period (m/sec or m/min).
Men: 1.37 m/sec; Women: 1.30 m/sec
from textbook
What is normal walking speed?
1.5m/s (3mph)
from notes
Cadence is:
The # of steps taken during a specified time period (steps/min).
C = Steps/Time
Men: 108 steps/min; Women: 118 steps/min
110-120 range; women walk faster due to shorter steps.
Stride Length is:
Spatial Data
The linear distance between two (2) sucessive events (IC in normal gait) on the same limb.
Right heel contact to right heel contact; Walking Speed/0.5cadence
Men: 1.51m; Women: 1.32m; 1.56.5cm (lectures)
What are the two main subphases of Gait?
Stance & Swing
Define Stance:
Temporal Data
The time when the foot is in contact with the support surface during one gait cycle.
Right foot IC —> right foot Toe Off
62% GC
Stance consists of:
DLS —> SLS (right) —> DLS
IC, LR, MSt, TSt, PSw
DLS = Double Limb Stance; SLS = Single Limb Support
Swing consists of:
Single Limb Support (Left)
ISw, MdSw, TSw
What is the duration of Stance?
0.62 sec (62% GC)
Occurs from 0% to 62% GC
Define SLS:
Single Limb Support
The time when only one foot is in contact with the support surface during one GC.
right foot SLS is initiated by left toe-off and ends at left foot IC
Stance
What is the duration of SLS?
0.38 sec (38% GC)
Occurs from 12% - 50% GC
Stance
Define DLS:
Double Limb Support
The time when both feet are in contact with the support surface during one GC. Weight transfer is occuring between both limbs.
Remember: Initial DLS (LR) & Terminal DLS (Pre-swing)
0.24sec (24% GC)
Stance
Define Loading Response (LR):
AKA: Initial Double Limb Stance
The time when right foot is in IC, and ends at left foot toe off.
Controlled weight transfer to the stance limb; shock absorption.
2% - 12% GC
Stance
Define Pre-Swing:
AKA: Terminal Double Limb Stance
The time when the support limb is being unloaded.
ie, left foot IC to right foot Toe-off
50% - 62% GC
Define Swing:
Single Limb Support
The time when the foot is airborne during one GC.
ie, right foot toe-off to right foot IC
Initicial Contact is:
the instant when the foot contact the support surface (flat foot)
IC: Flat Foot (R); Toe Off (L)
Heel contact to advance CoM forward (heel rocker).
What are the objectives of IC & LR?
IC + LR = Weight Acceptance
- Shock Absorption - lowest CoM position 5%
- Stability
- Forward Progression - to vertical tibia (12% GC)
IC + LR = 0% - 12% GC
Stance
12% - 31% GC:
Single Limb Support
Mid Stance (MSt)
Objectives: stability + fwd progression
1st half of SLS; ankle rocker.
Flat foot (R); Toe Off (L) to Heel Off (L)
Highest CoM position is during:
CoM = Center of Mass
Mid Stance - 30%
Center of Mass is at ** S2** vertebra.
Stance
31% - 50% GC:
Single Limb Support
Terminal Stance
Heel rise (R) initiates 2nd half of SLS; Heel Off (L) + IC (L)
Objectives: stability + fwd progression (forefoot rocker)
Stance
50% - 62% GC:
Double Limb Stance
Swing Limb Advancement
Pre-Swing
Body wgt transferred from trailing to ‘reaching’ limb;
IC (L) w/Flat Foot (L) + Toe-Off (R)
Objectives: Position for swing + accelerate progression
Stance: Pre-Swing
What enables limb to prepare for swing?
Unweighting, which is tranferring wgt from trailing to reaching/leading limb.
Results in toe only contact (toe rocker)
Swing Phase
62% - 75% GC
First 1/3
Swing Limb Advancement
Initial Swing
Foot lifts from ground during 1st one-third of swing & advances to opposite stance foot.
Flat foot (L) w/Toe-Off (R) = Parallel Thighs
Objectives: Foot clearance + limb advancement
What joint motion achieves foot clearance during ISw?
Knee flexion
When are the thighs parallel?
Femurs are both vertical!
Initial Swing
62% - 75% GC
Swing
75% - 87% GC
Middle 1/3
Mid Swing
Parallel thighs w/vertical tibia (R) due to limb advancement;
Objectives: Foot clearance + limb advancement
What joint motion in Mid Swing allows toe clearance?
Ankle dorsiflexion
Swing
87% - 100% GC
Final 1/3
Terminal Swing
Tibia advances + limb prepares for IC (heel first)
Vertical Tibia (R) prepares for IC (R)
Objectives: Complete limb advancement + prepare for stance
How does the knee prepare for heel contact during TSw?
Knee extends
