Gait - pattern of walking

Hi Friends,
we are going to start a CME lectures on Pathological gates . We will also try to understand the science behind normal GAIT (walking pattern) and abnormal one. Understanding Gait
pattern is very important for healthcare professionals as this may also inter related to spinal problems sometimes.
Students can send their queries in comment box for more details.

Introduction

Human locomotion or gait may be described as a translatory progression of the body as a whole, produced by coordinated rotatory movements of the body segments.

Ralston- noted that human gait involved to take an individual from one point to another & minimal expenditure of energy.

Normal gait is rhythmic & is characterized by alternating propulsive & retropulsive motion of lower extremity.

In normal walking, a gait cycle commences when the heel of the reference extremity contact the supporting surface & ends when the heel of the same extremity contacts the ground again.

Gait cycle

Stance phase- it consists 60% of gait cycle

• Initial contact
• Loading response
• Mid-stance
• Terminal stance
• Pre-swing

IC- beginning of 1st phase when heel contacts the contact surface

LR- position of the Ist double support period of the stance phase from IC, until the c/l extremity leaves the ground.

MSt- portion of the single limb support stance phase begins when c\l extremity leaves the ground, ends when the body is directly over the supporting limb.

TSt- last portion of the single limb support stance begins with heel rise, continues till c\l extremity contacts the ground.

PSn- portion of stance phase begins with 2nd double support period from IC of c\l extrenity to toe-off of the reference extremity.

Swing Phase-40% of the gait cycle

Initial swing Mid swing Terminal swing

Portion of swing from the point portion of the swing phase from portion of the

When the reference extremity max. Knee flexion of ref. extremity swing phase from

Leaves the ground to maximum to a tibial vertical position

Knee flexion of the same.

Tibial vertical to

Just prior to initial

contact

Pathological gait may be viewed as an attempt to preserve as low a level of energy consumption as possible - by exaggerations of the motions at unaffected levels.

M.Saunders et al

* In abnormal gaits, the heel may not be the first part to contact the ground.: the gait cycle may be considered to begin when some portion of the reference extremity contacts the ground & ends when that same portion contacts the ground again.

Analysis

* The rapid speed at which the motion takes place makes a spontaneous visual analysis of pathological gait difficult.

* { in one second, a highly complex, multi-joint, bipedal, neuro-musculo-skeletal locomotor system (proceeding at the rate of about 3 m/ hour) transverses a distance of about 5 feet.}

Types of analysis- ( 2 broad categories)

1. Kinetic analysis:

Is used to determine the forces involved in gait i.e. GRF, C.O.P., C.O.M, mechanical energy, moments of force, power, work , joint reaction forces, { GRF- the net vertical & shear/ horizontal forces acting below foot & supporting surface. (3-D)

C.O.P - point of application of the GRF vector that is located below the feet in bilateral stance.

C.O.M- weight of the body is said to be concentrated COM; at the level of S2

rest in next session..........