Gait Cycle

What is stride length?

heel strike to ipsilateral heel strike

What is step length?

heel strike to contralateral heel strike

What is step width?

mid-heel to mid-heel

What is foot angle?

line of progression and mid-heel through 2nd toe

What are the temporal descriptors of gait?

cadence, stride time, step time

What is cadence?

the number of steps per unit of time (steps/minute)

What are the spatial descriptors of gait?

stride length, step length, step width, foot angle

What percent of the gait cycle do we spend in stance phase?

60% of the gait cycle

What percent of the gait cycle do we spend in swing phase?

40% of the gait cycle

What percent of the gait cycle do we spend in double limb support?

20% of the gait cycle

What are the stance phase phases?

initial contact, loading response, mid stance, terminal stance, pre-swing

What are the swing phase phases?

initial swing, mid swing, terminal swing

Which phases have the task of the weight acceptance?

initial contact and loading response

Which phases have the task of single limb support?

mid-stance and terminal stance

Which phases have the task of swing limb advancement?

pre-swing, initial swing, mid swing, terminal swing

What phases is the 1st rocker or heel rocker associated with?

initial contact to loading response

When does the 1st rocker or heel rocker occur?

when heel first makes contact with ground and begins to "roll" forward

helps control forward momentum as ankle slowly moves from DF to PF

What phase is associated with the 2nd rocker or ankle rocker?

midstance

When is the ankle rocker active?

ankle rocker takes over once the foot is flat on the ground

key for stability

What does the ankle rocker allow for?

the tibia to move forward over the foot, helping to advance the body's center of gravity

What phase is associated with the 3rd rocker or forefoot rocker?

terminal stance

When does the forefoot rocker begin?

as the heel lifts off the ground, transitioning the body's weight to the ball of foot and toes

What does the forefoot rocker allow the body to do?

allows the body to push off, creating the propulsion needed to initiate the next step, provides necessary force to propel body forward

What percent of the gait cycle is initial contact?

2% (0-2)

What is associated with initial contact during weight acceptance?

beginning of double limb support

What percent of the gait cycle is loading response?

8% (2-10)

What is associated with loading response during weight acceptance?

period of double limb support

first rocker (heel rocker)

When does loading response begin?

after initial contact

When does loading response end?

when contralateral limb is lifted for swing

General info about 1st rocker or heel rocker:

fulcrum is rounded calcaneus

occurs during initial contact and loading response

What muscles are working during 1st rocker or heel rocker?

pre-tibial muscles control ankle PF and the pull tibia forward

pre-tibial muscles draw tibia forward - cause flexion moment at knee

quadriceps muscles control knee flex

What happens by the end of the heel rocker or 1st rocker?

foot is on the ground, tibia vertical and knee 20 degrees flexed

What percent of the gait cycle is midstance?

20% (10-30)

When does midstance begin?

when the contralateral foot leaves the ground

When does midstance end?

when BW travels forward until aligned over the forefoot

General info about the 2nd rocker or ankle rocker:

occurs during midstance

momentum causes tibia to move forward (passive ankle DF)

advancement of tibia over the stationary foot at midstance

What muscles are working during 2nd rocker or ankle rocker?

soleus and gastroc eccentrically control ankle DF - provide stable base for knee "extension"

What percent of the gait cycle is terminal stance?

20% (30-50)

When does terminal stance begin?

with BW over forefoot (heel rise of the stance limb) (COM anterior to foot)

When does terminal stance end?

when contralateral foot hits ground

What is associated with 3rd rocker (forefoot rocker) during single limb support?

metatarsal heads serve as axis of rotation for body weight advancement

center of pressure reaches met heads

end range ankle DF reaches (tibia moving forward) facilitates center of pressure to move distally on foot and generate heel off

body progresses beyond the area of foot support

What percent of stance phase is preswing?

10%

What is the second period of double limb support?

pre-swing

When does preswing begin?

when contralateral foot hits the ground

When does preswing end?

with ipsilateral toe off

What does pre-swing prepare for?

toe clearance during swing phase

What percent of the gait cycle is initial swing?

15% (60-75)

How much of swing phase is initial swing?

1/3

When does initial swing begin?

when foot leaves the ground

When does initial swing end?

when swing foot is opposite contralateral or stance foot

What percent of the gait cycle is midswing?

10% (75-85)

When does mid-swing begin?

when swing foot opposite to contralateral (stance) foot

When does mid-swing end?

when the tibia is vertical

What happens during midswing?

knee extending with ankle DF to clear toes

What percent of the gait cycle is terminal swing?

15% (85-100)

When does terminal swing begin?

when the tibia is vertical

When does terminal swing end?

when foot strikes floor

What happens during terminal swing?

limb prepares for heel contact

during gait what phase is the high point of vertical translation?

midstance

during gait what phase is the low point of vertical translation?

initial contact

What is potential energy?

the energy of an object or a system due to the position of the body or the arrangement of the particles of the system

What is kinetic energy?

the energy which an object possesses due to its motion

What sagittal ROM is required for normal gait?

- pelvis 2-4 degrees ant/post tilt

- hip 10 degrees ext - 30 degrees flexion

- knee 0 degrees to 60 degrees flexion

- ankle 10 degrees DF to 20 degrees PF

- 1st MTP 0-55 degrees extension

when is the hip maximally flexed during gait?

loading response and late swing

When is the hip maximally extended during gait?

end of terminal stance

When is the knee slightly flexed during gait?

initial contact

When is the knee maximally extended during gait?

terminal stance and terminal swing

When is the knee maximally flexed during gait?

mid swing

When is the ankle slightly plantar flexed during gait?

initial contact

When is the ankle maximally dorsiflexed during gait?

terminal stance

When is the ankle maximally plantar flexed during gait?

initial swing

What motions are occurring during loading response?

knee = flexing

ankle = plantar flexed then dorsiflexing

What motions are occurring during midstance?

hip = extending

knee = flexing then extending

ankle = dorsiflexing

What motions are occurring during terminal stance?

hip = extending

knee = extending then flexing

ankle = dorsiflexing

What motions are occurring during preswing?

hip = flexing

knee = flexing

ankle = plantarflexing

What motions are occurring during initial swing?

hip = flexing

knee = flexing

ankle = dorsiflexing

What motions are occurring during mid swing?

hip = flexing

knee = extending

ankle = dorsiflexing to neutral

What motions are occurring during terminal swing?

hip = flexed ....... slightly extending

knee = extending then slightly flexing

ankle = dorsiflexed - near neutral

When is the hip max adducted?

during midstance

When is the hip max abducted?

during initial swing

Pronate to get foot on ground as a ________________

mobile adapter

Supinate after foot is on the ground to create a ____________________

rigid lever

When is potential energy the highest?

midstance and midswing

When is kinetic energy highest?

at initial contact