Gait Theory & Spatial Temporal Parameters

Question 1

Six Determinants of Gait

Answer 1

• States that energy costs during gait (vertical & horizontal displacements) is minimized by six actions of the pelvis, hip, knee, & ankle.
• Sagittal plane: hip and knee flexion, knee and ankle flexion
• Transverse Plane: Pelvic rotation
• Frontal Plane: lateral pelvic tilt
• Premise 1: gait is the translation of the COM through space along a pathway requiring the least expenditure of energy
• Premise 2: Minimizing the amount that the body’s COG is displaced from the line of progression is the major mechanism for reducing the muscular effort of walking, & consequently, saving energy.
• Based upon Gait Kinematics: study of motion of mechanical points of joints during upright mobility Involves:
  1. extent of joint movement (ROM)
  2. Speed (velocity of body & limbs
  3. Direction (joint motion: flex, ext)
• classifies two major phases: stance, swing
• Phases indicates specific phases in cycle
• each joint shows “normative data” for an adult

Question 2

Inverted Pendulum Theory

Answer 2

• States that the stance leg is kept relatively straight during single support, functioning like an inverted pendulum
• COM, located near the hip, travels in a series of arcs prescribed by each single support phase. The limb travels like a pendulum, thus does not require much energy.

Question 3

Gait is measured by

Answer 3

• m/s
• age
• sex
• level of community access

to determine health status

Question 4

Functional ambulatory terms in rehab (with or w/o assisted device)

Answer 4

• safely crosses the street (1.3 m/s)
• community ambulation (going to the store, has to adapt)
• limited community ambulator (maybe due to pain, 1 or 2 blocks)
• household ambulator
• dependent ambulator (requires assitance of a person)

Question 5

Preferred Gait Speed and Slow and Fast Speeds

Answer 5

• a person’s normal comfortable speed of gait may be referred to as preferred, natural, self-selected, or free. When assessing gait note that the gait is self selected or preferred gait speed.
• slow and fast speeds of gait refer to speeds slower or faster than a person’s normal comfortable walking speed, designated in a variety of ways

Question 6

Gait velocity indicates…

Answer 6

• function, falls, and requirement for specialized skill care
• Gait speeds:
• > 1.0 m/s: predictive of completing yard work, climb flights of stairs
• < 1.0 m/s: benefit from fall prevention, >0.67 to complete self care, >0.89 for household activities
• < 0.60 m/s: predicts future risk of falls and hospitilization, tends to require assitance with ADL and IADLs, >0.49 to cross street
• < 0.40 m/s: lomger length of stay in acture care, likely d/c to skilled nursing, inpatient rehab, or nursing home setting or home health services
• Use 10 m walk test to measure gait velocity

Question 7

Gait cycle (2 phases)

Answer 7

• Stance phase: during a walking cycle, a given foot is in contact with ground, heel strike to toe off, 60%
• Swing phase: during the walking cycle, a given foot is not in contact with ground, 40%
• 20% is double support, 80% single support

Question 8

Double & Single Support

Answer 8

• There are two periods of double support occuring between the time one limb makes intial contact and the other one leaves the floor at toe off
• At normal walking speed, each period of double support occupies about 11% of gait cycle, which makes approx, 22% for a full cycle.
• The body is thus supported by only one limb for nearly 80% of cycle. The approx. value of 10% for each double support phase is usually assigned to each of the double support periods.

Question 9

Gait Spatial & temporal parameters

Answer 9

Foundational: step & stride length (spatial), step& stride length are equal bilaterally
Stride length: is the typical measure used in gait analysis
Gait cycle:right initial contact to right initial contact

Question 10

Spatial parameters

Answer 10

• Step length:calcaneus to contralateral foot calcaneus
• Stride length: calcaneus to calcaneus of ipsilateral calcaneus, 0.67 m women, 0.76 m men
• Step width: mid point of calcaneus to mid point of calcaneus
• Foot angle: toes pointed out
• measured in m
• Step and stride length is a critical measure in PT. The longer your step or stride length the more ground you’ll cover!
• Determinants of stride length: age, height, males>, injury/illness

Question 11

Gait Temporal Parameters

Answer 11

• Number of steps per min (cadence): normal 80-90 steps per min in adults
• Swing time or stance time (secs)
• Gait velocity essential for PT (age, six determinants), 1.2-1.4 m/s for adults

Question 12

Clinical application

Answer 12

• PTs use several important measures
• Gait velocity: in all settings determines discharge preferences, intervention outcomes
• stride length: injuries (orthopedic), neurological clients
• level of community ambulation

Question 13

Calculation of Gait Measures

Answer 13

• Calculation of Gait velocity (gait velocity=cadence x stride length)
• Example: cadence of 80 steps per min x 0.9 m (stride length) =0.72 m/s (move decimal point to left two times to account for seconds)
• Cadence= # of steps taken by person per unit of time. Cadence is measured per min
• A shorter step length will result in an increased cadence at any given velocity
• A longer step length will result in a decreased cadence at any given velocity