Gait Flashcards
What occurs during the stance phase?
heel contact to toe off, foot is on ground supporting body weight (60% of gait cycle)
In the gait cycle, what percentage is stance and swing phase?
60% stance and 40% swing
What occurs during the swing phase?
toe off to heel contact, foot in the air being advanced forward
Would increasing double limb support time increase or decrease speed of gait?
decrease
When does mid stance occur during gait (stance phase)?
30%
Mid swing in the right leg corresponds with what phase in the opposite leg?
mid stance
When does heel off occur as opposed to toe off in the stance phase of gait?
heel off - 40%; toe off - 60%
What is push off?
40-60% of stance phase
What are the four periods of stance?
loading response, mid stance, terminal stance, pre swing
What are the three periods of swing phase?
initial swing, mid swing, terminal swing
Vertical Displacement in Gait
5 cm, min. height at midpoint of periods of double limb support, max. height at midpoint of periods of single limb support
Lateral Displacement of Gait
4 cm, max. occurs at midpoint of stance phase of the ipsilateral lower extremity
When is the center of mass at its lowest and most central position (least displacement) during gait?
in the middle of double limb support (5% and 55% of gate cycle)
What are the two ways we describe gait?
spatial and temporal
Stride Length
distance between heel contacts on SAME foot (144 cm, 4.5 ft)
Step Length
distance between heel contacts of opposite feet (72 cm, 28 in.)
Step Width
lateral distance between heel centers of 2 consecutive foot contacts (7-9 cm)
Foot Angle
degree of toe out, angle between line of progression of the body and long axis of the foot (7 degrees)
What is normal walking speed?
1.37 m/sec; best and most functional measure of individual’s walking ability
When does the hip posterior tilt?
0-10%, second half of stance, terminal swing
When does the hip anterior tilt?
during single limb support, initial and mid swing
What hip ROM in sagittal plane is needed for gait?
30 degrees of flexion and 10 degrees extension
Sagittal Plane Kinematics of the Hip during Gait
heel contact - flexed 30 degrees; extends during stance to 10 degrees before toe off, flexion initiated pre swing, toe off at 0 degrees, in the swing phase hip flexion to advance leg
What ROM in the sagittal plane is needed in the knee during gait?
extension to 60 degrees of flexion
What is the knee flexed to at toe off?
35 degrees
When does max flexion of the knee occur during gait?
mid swing (concentric hamstring)
At heel contact, is the knee fully extended?
no, it is flexed 5 degrees, full extension just prior to heel contact
What ROM is needed at the ankle during gait?
10 degrees dorsiflexion and 20 degrees plantarflexion
Just after toe off, how far is the ankle plantarflexed?
15-20 degrees
During the swing phase, describe how the ankle moves.
ankle dorsiflexed then to neutral
How much extension is needed in the MTP from heel off to before toe off?
45-55 degrees
Summary of Sagittal Plane Heel Contact
joints aligned to reach forward, elongate LE to put foot flat on ground
Summary of Sagittal Plane After Heel Contact
knee flexion and ankle PF cushion loading for smooth weight acceptance
Summary of Sagittal Plane Mid-Stance
joints extend to support body weight and increase heigh to allow contralateral LE swing
Summary of Sagittal Plane Swing
leg shortens for clearance, reaches forward for heel contact
What ROM is needed in the hip in the frontal plane?
10-15 degrees
What occurs in the hip as weight is accepted on the right leg and slight drop occurs in left leg?
pelvic-on-femoral adduction in the right leg
When does the hip abduct?
between mid and terminal stance
What are three possible causes of deviations in the frontal plane kinematics of the hip?
weakness of hip abductors, decreased shortening of swing leg, leg length discrepancy
Frontal Plane Kinematics of the Knee
small amounts of angular movement, more apparent in individuals with abnormal alignment due to compartmental arthritis
Frontal Plane Kinematics at the Ankle
very small and irrelevant
Frontal Plane Kinematics at the Subtalar Joint
inverted 2-3 degrees at contact, everts to mid stance (max 2 degrees eversion reached), back toward inversion (neutral at heel off), inverted 6 degrees between heel and toe off, returns to slight inversion during swing prepare of heel contact
Frontal Plane Kinematics Summary of Hip
minimizes vertical displacement of center of mass
Frontal Plane Kinematics Summary of Pronation/Eversion
motion after heel contact acts in weight acceptance/flexible structure for ground contact
Frontal Plane Kinematics Summary of Inversion
between heel off and toe off for rigid foot structure for propulsion (causes supination of foot)
Horizontal Plane Kinematics ROM in Hip
3-4 degrees each way
What is the motion in the horizontal plane that occurs at the hip in order to advance the LE?
internal rotation
How much ER occurs at the knee at heel contact?
2-3 degrees
How much IR occurs at the knee at toe off?
5 degrees
Horizontal Plane Kinematics at the Foot/Ankle
irrelevant
What motion accompanies IR of the pelvis, femur, and tibia after heel contact to foot flat?
subtalar eversion (pronation)
During stance (15-20% beyond), the external rotation at the pelvis, femur, and tibia until toe off occurs with what motion at the subtalar and what does this allow?
supination/inversion; allows PF to work without collapsing under body weight
Decreased trunk motion could affect energy expenditure during gait how.
increase (10%)
Does decreasing speed of gait increase or decrease energy expenditure?
increase (increasing and decreasing speed both increase energy)
Hip Extensor During Gate
gluteus maximus eccentric during terminal swing, strong contraction during heel contact to prevent forward flexion of trunk, support body weight and extend hip during heel contact to mid stance (hamstrings only active in first 10%)
When are the hip flexors active during swing?
the first 50% of swing
Which muscles are most active with single leg support to control frontal plane deviation of the hip?
gluteus medius and minimus
When are the hip adductors active during gait?
heel contact (adductor magnus assists with extension), after toe off to assist with hip flexion
Which rotators are active during the stance phase?
IR - stance phase to rotate contralateral pelvis forward; ER - early stance to control alignment in horizontal plane and eccentric control of IR
When are the knee extensor most active during gait?
after heel contact to control knee flexion in first 10%
When are the knee flexors most active during gait?
hamstrings most active just before or just after heel contact
A weakness in this muscle could result in “foot slap.”
tibialis anterior
When are the gastrocnemius and soleus most active during gait?
after heel off, active through stance phase
If the posterior tibialis was weak, what could result?
shin splints, decreased MLA, rapid pronation
When are the peroneals active during gait?
20-30% foot flat to mid stance to just after heel off, act with PF, act as pronator/evertor
Foot Intrinsics during Gait
stabilize MLA
When are the erector spinae active during gait?
slightly before heel contact to foot flat (20%, similar to glut. max. to prevent forward flexion of trunk); from 45-70% after heel off to after toe off
Ground Reaction Forces of 3 Axes
vertical - 120% BW; anterior-posterior - 20% BW; medial-lateral - 5% BW
When narrowing step width to walk on ice, which forces are we attempting to minimize?
medial-lateral ground reaction forces
Impairment: ankle plantar flexion contracture
compensations - knee hyperextension (mid stance), forward trunk lean (terminal stance)
Impairment: foot drop
compensation - excessive knee and hip flexion
Impairment: reduced knee flexion
compensation - vaulting
Impairment: weak quadriceps
compensation - forward trunk lean
Impairment: knee flexion contracture
compensation - exaggerated knee and hip flexion
Impairment: reduced knee flexion and/or lack of ankle dorsiflexion
compensation - hip circumduction
Walking is of least muscular effort. (T/F)
True
What is used to analyze gait in biomechanics labs?
synchronized cameras, force plates for ground reaction forces, EMG measures
What is defined as the stride?
period of foot contact to same foot contacting again
What is defined as a step?
events between heel contact of opposite foot
Stride is synonymous with gait cycle. (T/F)
True
When does the push off occur during the gait cycle?
40-60%
What is early swing?
toe off to mid swing, 60-75%
When does mid swing occur?
75-85%
When does late swing occur?
85-100%
How is the center of mass (CoM) related to speed?
slows down when support limb is in front of CoM, speeds up when support limb is behind CoM (falling away from support leg)
In the kinematics of gait, in what plane is most of the angular rotation occuring?
primarily in sagittal plane, motion also occurs in frontal and horizontal planes
When does the hip rotate counterclockwise during gait?
from heel contact to foot flat in the stance leg, rotation is slight
When does the hip rotate clockwise in gait?
from foot flat through rest of stance in stance leg
When do the pelvis, femur, and tibia start to externally rotate during gait?
15-20%
What motions reduce vertical displacement of CoM?
horizontal plane pelvic rotation, sagittal plane ankle rotation, stance phase knee flexion, frontal plane pelvic rotation
To minimize medial-lateral displacement of CoM, minimize step width. What is the primary motion contributing to this?
frontal plane hip motion
Which muscles function with the tibialis anterior to DF concentrically for foot clearance?
extensor digitorum and extensor hallucis longus
Describe the path of the center of pressure (CoP) during gait.
at heel contact it is just lateral to midpoint of the heel, moves to lateral midfoot at midstance and medial forefoot during heel to toe off
What torque is applied at the knee at the instant of weight application?
varus
