Gait Flashcards
external appliance worn to restrict or assist motion or to transfer load from one area to another
orthosis
plural = orthoses
a replacement of all or part of the leg or arm
prosthesis
plural = prostheses
traditional gait phases in order:
Rancho terminology in order:
heel strike, foot flat, midstance, heel off, toe off, acceleration, mid swing, deceleration
initial contact, loading response, midstance, terminal stance, pre swing, initial swing, midswing, terminal swing
stance phase = ___%
swing phase = ____ %
60%
40%
phases of gait cycle Rancho terminology
initial contact 0%
loading response 0-10%
midstance 10-30%
terminal stance 30-50%
pre swing 50-60%
____________________________________________
initial swing 60-73%
midswing 73-87%
terminal swing 87-100%
which phases of gait in the stance phase are in single support? double support?
single: mid stance & terminal stance (40%)
double: initial contact, loading response, pre swing (20%)
rate of linear forward motion of the body
measured in?
velocity
(m/sec)
number of steps taken per unit of time
measured in?
cadence
(steps/min)
heel strike to ipsilateral heel strike
stride length
heel strike to contralateral heel strike
step length
width of base of support
step width
what is considered the 6th vital sign?
walking speed
what gait speed is considered a community ambulator?
0.8 m/sec or greater
1 stride = _____ = ______
1 gait cycle = 2 steps
produces external torque/moment:
– examples:
external forces
– ground reaction force, gravity/air resistance/friction
Internal forces usually respond to what type of external factor?
Internal forces usually respond to external torque created by the ground reaction force (GRF).
forces applied to the body by the ground, opposing forces applied to the ground during a step
GRF in gait
GRF components:
vertical
A-P
Med-Lat
what direction(s) are the GRF coming from in:
– heel strike
– foot flat
– toe off
– vertical, A-P
– vertical
– vertical, A-P
when does the foot exhibit M-L GRF?
very small amount of time in loading response
vertical GRF:
– 2 peaks = ___% of body weight
–> F1 =
–> F3 =
– 1 valley = ____% of body weight
–> F2 =
– 110%
–> at weight acceptance, due to the action of body momentum
–> at terminal stance, caused by the push of ankle PFs against the floor in combination with the downward acceleration of COG
– 80%
–> at midstance, created by the rise of COG
how do joint angles and GRFs interact?
moment aka torque
potential for a force, acting a distance from the axis of rotation, to produce rotation of a segment
– units?
moment = torque
– Nm or kgm
what is the equation for torque?
torque = force x moment arm
** moment arm = perpendicular distance between axis of rotation and line of action of the force
what is the right hand rule?
the torque is in the direction along the axis of the spin angular velocity which would be produced by it
– when turning right hand counterclockwise: thumb will point outwards
– when turning right hand clockwise: thumb will point inwards
In the stance phase of gait, weight acceptance, and single-limb support are two essential functional tasks. What primary outcome do these tasks contribute to?
forward progression
In the swing phase of gait, swing limb advancement is one functional task. What is it needed for?
Foot clearance
What two phase make up the first rocker?
a) Loading response and terminal stance
b) Initial contact & pre swing
c) Mid-stance & initial contact
d) Initial contact & loading reponse
d) Initial contact & loading reponse
In Weight Acceptance, which three main objectives are achieved during the loading response?
a) Shock absorption and impact deceleration
b) Weight-bearing stability, maintain COG and preservation of progression
c) Shock absorption, weight bearing stability and preservation of progression
d) Impact deceleration and increase speed and maintain progression
c) Shock absorption, weight-bearing stability, and preservation of progression
task 1: weight acceptance (WA):
loading response objectives (3)
shock absorption
weight bearing stability
preservation of progression
what is initial contact?
what percentage of the gait cycle?
the moment when the foot strikes the ground
0%
During Initial Contact, what position is the ankle held in?
neutral: held by pre-tibial muscles
What is the typical position of the knee during Initial Contact?
a) Full extension (5 degrees of flexion)
b) Slight flexion (15 degrees)
c) Fully flexed (90 degrees)
d) Slight hyperextension
a) Full extension (5 degrees of flexion)
What role does the hip play during Initial Contact?
a) Allows for maximum extension
b) Provides a position for optimal forward progression and stability
c) Prevents knee flexion
d) Initiates swing phase
b) Provides a position for optimal forward progression and stability
What is the typical position of the hip during Initial Contact?
peak flexion 20 degrees
What is the critical event in initial contact?
heel contact
what muscle activity is needed for each external moment in initial contact?
– hip ____ moment
– knee _____ moment
– ___ moment
– [flexion] hamstrings and gluteals for hip stability
– [extension] quadriceps for knee stability
– [PF] pre-tibials to counterbalance PF moment
what is loading response?
what percent of the gait cycle?
shock is absorbed while forward momentum is preserved. Foot flat position is achieved
0-10%
loading response positions:
– ankle
– knee
– hip
– 5 deg of PF; subtalar eversion
– 20 deg of flexion for shock absorption
– flexion 20 deg.
at what point is the 1st rocker?
during loading response at the heel
what are the critical events during loading response? (3)
- pre-tibial muscles eccentrically control PF (5 deg)
- quads active to control knee flexion moment
- hip extensors active for stability
what muscle activity is needed for each external moment in loading response?
– hip _____ moment
– knee ______ moment
– ____ moment
– [flexion] hamstrings and gluteals for hip stability
– [flexion] quadriceps to counterbalance flexion moment
– [PF] pre-tibials to counterbalance PF moment. Calf for stance stability
task 2: single limb support:
midstance objectives (2)
- progression over stationary foot
- limb and trunk stability
task 2: single limb support:
terminal stance objectives (2)
- progression of body beyond the supporting foot
- limb and trunk stability
what is midstance?
percentage of gait cycle?
body progresses over foot in controlled manner. contralateral limb provides momentum
10-30%
midstance positions:
– ankle
– knee
– hip
– DF controlled eccentrically
– extension
– neutral
at what point is the 2nd rocker?
during LR/midstance at the ankle
what is the critical event during midstance?
dorsiflexion controlled eccentrically by gastroc and soleus
what muscle activity is needed for each external moment in midstance?
– hip ____ moment
– knee ______ moment
– ___ moment
– [extension] no muscle activity
– [extension] quadriceps for stance stability
– [DF] calf (eccentrically controls) for stance stability and to counterbalance DF moment
terminal stance positions:
– ankle
– knee
– hip
– noted by heel rise (normal DF ROM 20 deg), decline in gastroc/soleus mm activity
– full extension to maximum step length
– 20 deg of apparent hyperextension for maximum step length (peak hip ext)
what is the critical event in terminal stance?
trailing limb (posterior positioning)
at what point is the 3rd rocker?
terminal stance at forefoot (heel off)
what muscle activity is needed for each external moment in terminal stance?
– hip _____ moment
– knee _______ moment
– ___ moment
– [extension] no muscle activity
– [extension] no muscle activity
– [DF] Large! calf to counterbalance DF moment
task 3: swing limb advancement:
pre-swing objectives (2)
– position of limb for swing
– accelerate progression
task 3: swing limb advancement:
initial swing objectives (2)
– foot clearance
– advancement of the limb from the trailing limb position
task 3: swing limb advancement:
mid swing objectives (2)
– limb advancement
– foot clearance
task 3: swing limb advancement:
terminal swing objectives (2)
– complete limb advancement
– prepare limb for stance
what is preswing?
what percentage of the gait cycle?
forefoot remains on the ground. knee rapidly flexes while weight is shifted to other limb
50-60%
preswing positions:
– ankle
– knee
– hip
– 2nd arc of PF (15 deg); no gastroc/soleus mm activity (no push off); 60deg great toe extension
– passive knee flexion (40 deg); prepares limb for toe clearance
– 10 deg apparent hyperextension
what is the critical event of pre swing?
passive knee flexion (40 deg)
what muscle activity is needed for each external moment in pre swing?
– hip _____ moment
– knee _______ moment
– ___ moment
– [extension] hip flexors to counterbalance extension moment and initiate swing
– [flexion] no muscle activity
– [DF] Calf to counterbalance DF moment (early); pre tibials for foot clearance (late)
Initial swing positions:
– ankle:
– knee
– hip
– nearly neutral
– peak flexion for toe clearance (60 deg); peak mm activity of biceps femoris short head, sartorius, gracilis
– 15 deg flexion; peak mm activity of gracilis and sartorius
what are the two critical events for initial swing?
– peak flexion (60 deg) for toe clearance
– 15 deg. hip flexion
what percentage of the gait cycle is initial swing?
60-73%
what is midswing?
what percentage of the gait cycle?
tibia is perpendicular to the ground
73-87% of gait cycle
midswing positions:
– ankle
– knee
– hip
– neutral to slight DF
– passive ext. cause by the momentum of hip flexion (flexion to extension)
– peak flexion 25 deg
what is the critical event in midswing?
neutral to slight DF
what is terminal swing?
what percentage of the gait cycle?
leg reaches out to achieve step length. preparation for initial contact
87-100%
terminal swing positions:
– ankle
– knee
– hip
– neutral to prepare for heel strike
– extension to neutral (5 deg flex); ext. controlled eccentrically by the hamstrings; quads turn on in late terminal swing to prepare for WBing
– subtle retraction to 20 deg of flexion
what is the critical event during terminal swing?
knee extension to neutral (5 deg flex)
