Gait cycle basics

Question 1

Define Step length

Answer 1

Distance between initial contacts of alternating feet

Question 2

Define stride length

Answer 2

Stride = 2 Steps

A stride is the movement of the body between two successive steps.

Stride Length refers to the distance of consecutive initial contacts of the same foot with the ground

Question 3

Define Cadence

Answer 3

Step frequency per minute

Question 4

4 stance phase, 4 swing phase

Detail the stages of the Gait Cycle in order

Answer 4

Initial Contact

Loading Response

Midstance

Terminal Stance (Heel Off)

Initial Swing (Toe Off)

Pre Swing (Second Period of Double Limb Support)

Mid Swing

Terminal Swing (Tibia Vertical)

Question 5

Explain Initial Contact

Answer 5

Short period beginning when the foot touches the ground and is the first phase of double support:

Full extension of the knee, ankle moves from dorsi flexion (ground clearance) to neutral to plantar flexion

After this, Knee flexion begins

Plantar Flexion controlled by eccentric contraction of ankle dorsiflexors (Tibialis Anterior, EDL, EHL FT)

Knee extension caused by concentric contraction of the Quadriceps
Knee flexion caused by Eccentric contraction of Hamstring

Hip Extensors contract to stabilize the pelvis

Question 6

Explain Loading Response

Answer 6

Start of initial double limb Stance
Body absorbs the impact of the foot by rolling into pronation

Hip moves slowly into extension (Contraction of Adductor Magnus and Gluteus Maximus)

Ankle Dorsiflexors (Tib Ant) contract eccentrically to control plantar flexion moment

Quadriceps contract to counteract the flexion moment about the knee

Question 7

FEOL BACP

Contraction = GM + G ecc for E from F

Explain Midstance

Answer 7

Body is supported by one leg and begins to move from force absorption at impact, to propulsion forward

From elevation of the opposite limb until both ankles are aligned in the Coronal Plane

Gluteus Medius and Gastrocnemius eccentrically contract to transition the knee from flexion to extension.

Question 8

SH LG CCG

PBF
TPSSP

Explain Terminal Stance (Heel Off)

Answer 8

Begins when the supporting Heel leaves the ground and continues until the contralateral foot contacts the ground.

This event serves to propel the body forward

Tibialis Posterior stabilizes the ankle and places the subtalar joint into supination

Question 9

CFC + IFG

CC HF

Explain Pre Swing (Second Period of Double limb support)

Answer 9

Starts when contralateral foot contacts the ground continues until the ipsilateral foot leaves the ground. Provide the final burst of propulsion before the toe leaves the ground

Concentric contraction of the Hip flexors (Iliopsoas) to propel advancing limb

Question 10

Explain Initial Swing (Toe Off)

Answer 10

Start of single limb support for the opposite leg

From elevation of the limb to point of Maximal Knee flexion

Concentric contraction of the (Iliopsoas) causes Hip flexion

Ankle and toe extensors (Tib Ant, EHL) concentrically contract to dorsi flex the ankle for ground clearance

Question 11

Explain Mid Swing

Answer 11

Responsible for foot clearance and forward progression

Following knee flexion the Tibia becomes vertical and perpendicular to the floor toward the end of this phase

Ankle dorsiflexors (Tib Ant, EHL) isometrically contract for ground clearance

Hamstrings eccentrically contract to decelerate the limb

Question 12

Explain Terminal Swing (Tibia Vertical)

Answer 12

From the point where the Tibia is vertical to the point where the limb is preparing to come in contact with the ground once again (Initial contact)

Hamstrings concentrically contract to slow the forward motion of the thigh/hip and prepare for weight acceptance.

Quadriceps stabilize the knee