Gait Terminology

Base Of Support
The distane meaured between the left and right foot during progression of gait. The distance decreases as cadence increases. The average BOS for an adult is 2 -4 inches.
The number of steps an individual will walk over a period of time. The average value for an adult is 110-120 steps per minute.
Degree of toe-out
The angle formed by each foot's line of progression and a line intersecting the center of the heel to the second toe. The average degree of toe-out for an adult is 7 degrees.
Double Support Phase
Refers to the two times during a gait sycle where both feet are on the ground. The time of double support increases as the speed of gait decreases. This phase does not exist with running.
Gait Cycle
Refers to the sequence of motions that occur from one initial contact of the heel to the next consecutive initial contact of the same heel.
Pelvic Rotation
Rotation of the pelvis opposite the thorax in order to maintain balance and regulate speed. The pelvic rotation during gait for an adult is a total of 8 degrees, 4 degrees forward with the swing leg and 4 degrees backward with the stance leg.
Single Support Phase
Occurs when only one foot is on the ground and occurs twice during a single gait cycle.
Step Length
The distance measured between right heel strike and left heel strike. The average step length for and adult is 13 - 16 inches.
Stride Length
The distance measured between right heel strike and the following right heel strike. The average length for an adult is 26 - 32 inches.