Gait Analysis

Question 1

Heel Strike

Initial Contact

Answer 1

HS: the point when the heel of the reference or support limb contacts the ground at the beginning of stance

IC: the instant the foot of the lead extremity strikes the ground

Muscle Activation

• quads are active at HS through early stance to control knee flexion for shock absorption
• anke DF: decelerate the foot, slowing the PF from HS to foot flat

Question 2

Foot Flat

Loading Response

Answer 2

FF: point when the sole of the foot of reference limb makes contact with the ground: occurs immed. after HS

LR: first period of double limb support immediately after initial contact until contralateral leg leaves ground

Muscle Activity:

• **gastroc-soleus **are active from foot flat through midstance to eccentrically control forward tibial advancement

Question 3

Midstance

Midstance

Answer 3

MS: The point at which full body weight is taken by the reference limb

MS/RLA: the contralateral limb leave the ground, body weight is taken and advanced over and ahead of the support limb; period of single limb support

Muscle Activation:

• hip, knee, ankle extensors are active throughout stance to oppose antigravity forces and stabilize
• hip extensors control forward motion of the trunk
• hip ABD stabilize the pelvis during unilat stance

Question 4

Heel-off

Terminal Stance

Answer 4

HO: occurs after midstance as the heel of the reference limb leaves the ground

TS: last period of single limb support that begins with heel rise and continues until the contralateral leg contacts the ground

Muscle Activation:

• PEAK ACTIVITY of PF occurs just after heel off to push off and generates forward propulsion of body

Question 5

Toe Off

Preswing

Answer 5

TO: last portion of stance following heel off when only the toe of the reference limb is in contact with the ground

PS: the second period of double limb support from initial contact of contralateral limb to lift off of reference limb

Muscle Activation

• hip and knee extensors (hams and quads) may contribute to forward propulsion with brief burst of activity

Question 6

Acceleration

Initial Swing

Answer 6

A: the first portion of the swing phase fom toe-off of the reference limb until midswing

IS: the first portion of the swing phase from toe off of reference limb until maximum knee flexion of same extremity

Muscle activation:

• forward motion early in swing is achieved by brief activation of quads
• by midswing, the quad is silent and pendular motion is in effect
• hip flexors (iliopsoas) aid in forward limb propulsion

Question 7

Midswing

Midswing (RLA)

Answer 7

MS: the midportion of swing when the reference extremity moves directly below the body

MS/RLA: the portion of swing from max knee flexion to vertical tibial position

Muscle Activation

• foot clearance is achieved by contraction of the hip, knee flexors, and ankle DF

Question 8

Deceleration

Terminal Swing

Answer 8

D: end portion of swing phase when reference extremity is slowing down in preparation for HS

TS: from vertical tibial position of reference limb until just prior to initial contact

Muscle Activation:

• hamstrings during late swing to decelerate limb
• quads and ankle DF become active in late swing to prepare for heel strike