Definitions

The use of appropriate terminology is a fundamental aspect of forensic gait analysis. Despite the best efforts of practitioners to ensure that reports are understandable by as wide a readership as possible, the language used can be complex for the lay reader. Below are some definitions, in the context of forensic gait analysis, that may be useful in understanding a forensic gait analysis report.

Forensic gait analysis is the analysis, comparison and evaluation of features of gait to assist the investigation of crime. 

Gait                  the pattern of movement utilized during locomotion

Gait Cycle        one complete series of movements that is repeated to produce

                         locomotion

Locomotion      the ability to move oneself from one place to another

Walking            a method of locomotion that involves placing one foot on the ground

                         after the other, during which there is always at least one foot in contact

                         with the ground

Running            a method of locomotion that involves placing one foot on the ground

                         after the other, during which there is a phase when neither foot is

                         in contact with the ground

Note: the difference between walking and running is not dependent on the speed of movement.

Events of the gait cycle

Heel Strike      the point in time of the first contact of the foot with the ground

Foot Flat         the point in time of the first contact of the front end of the foot with

                       the ground

Heel Rise        the point in time at which the heel first leaves the ground

Toe Off           the point in time at which the foot first leaves the ground

Phases of the gait cycle

Stance            the period of time during which the lower limb in question is in contact

                       with the ground and is therefore providing support for the body

Swing             the period of time during which the lower limb in question is not

                       in contact with the ground

Double           the period of time during walking when both feet are in contact with

support           the ground

Parameters of gait

Step                heel strike of one foot to the next heel strike of the other foot

Stride              heel strike of one foot to the next heel strike of the same foot.

Base of gait    the distance between the rear most point of contact of the left and

                       right heels, measured at right angles to the line of progression

Toe out/in       the angle between the longitudinal axis of the foot and

angle              the line of progression.

Speed            the distance travelled in a known time period

Cadence        the number of steps taken in a known time period