Normal Gait Flashcards
gait cycle
time taken or sequence of motions occurring between two consecutive heel
strikes
● Time from one heel strike to the next ipsilateral heel strike
● Synonymous with stride length
COG
approximately 2 in (5 cm) anterior to the second sacral bone (S2)
● Propulsion pushes the COG anterior to the base of support (BOS)
● Slightly higher in males
stride length
1 gait cycle corresponds to 1 stride length
● Two step lengths added together make one stride length
● Approximately 56 in (142 cm)
step length
distance between the point of the heel strike of one foot and the point of the
heel strike of the opposite foot
● Approximately 28 in (71 cm)
step width
distance between the feet
● Normal step width: between 2 and 4 in (between 5 and 10 cm)
● Forms the BOS
● A larger BOS indicates a pathology involving balance (cerebellar problem, inner ear
problem, diabetes mellitus [DM], neuropathy)
lateral pelvic shift
side-to-side movement of pelvis during walking
● Necessary to center the weight of the body over the stance leg for balance
➤ Causes a relative adduction of the weight-bearing (WB) limb, facilitating adductors
➤ If the abductor is weak, Trendelenburg gait is seen
● Normal lateral pelvic shift: 1–2 in (2.5–5 cm)
➤ Increases if there is wider BOS
vertical pelvic shift
keeps COG from moving up and down by >2 in (5 cm)
● High point occurs during midstance (MSt)
● Low point during initial contact (IC)
➤ The heights of these points can increase during the swing phase if the knee is
fused or does not bend
● During the swing phase, the hip is lower on the swing side
➤ Pelvis rotates clockwise; thorax rotates counterclockwise
pelvic rotation
necessary to lessen the angle of the femur with the floor (lengthens the
femur)
● Rotation decreases the COG dip by decreasing the amplitude of displacement of the COG
● 4° on each side (forward on the swing leg; backward on the stance leg)
➤ To maintain balance, the thorax rotates in the opposite direction
cadence
number of steps per minute
● Increased cadence at the same speed → shorter step length
● For a typical gait cycle, cadence = 90–120 steps per minute
● Typical gait speed: 1.4 m/s (3 mph)
➤ Running cadence: 180 steps per minute
➤ Cadence is usually higher in females
double support
both limbs are in the stance phase at the same time
zero support/double float
both legs in the air (jogging, running)
● Period of time when both feet are not in contact with the ground
● Running requires a greater range of motion (ROM) than walking
➤ Example: hip flexion ROM
Walking: 40° to 45°
Running: 60° to 75°
● For running, the hip extensor strength is the most important factor
● Stride length is also important
metabolic cost of walking
5.5 kcal/min on a level walking surface
● Increases with age, abnormal gait, or use of an assistive device
mature walking
walking velocity and step length increase, cadence decreases
● Begins at about 6 to 7 years of age
temporal variables
Stride and step duration
● Cadence
spatial variables
● Degree of foot angle
● Width of BOS
● Step length
● Stride length
spatiotemporal variable
walking speed
initial contact (heel strike)
moment when the foot makes contact with the ground
loading response (foot flat)
weight is rapidly transferred onto the outstretched limb
➤ Midstance: body progresses over a single stable limb
midstance
body progress over a single stable limb
terminal stance (heel off)
progression over stance limb continues; body moves
ahead of the limb, and weight is transferred onto the forefoot
preswing (toe off)
rapid unloading of the limb occurs as weight is transferred
to the contralateral limb
initial swing
thigh begins to advance as the foot comes off the floor
mid swing
thigh continues to advance as the knee begins to extend and the foot
clears the ground
terminal swing (deceleration)
knee extends, and the limb prepares to make con-
tact with the ground for IC
