Chapter 12

Question 1

What are the requirements for mobility?

Answer 1

progression
postural control
adaptability

Question 2

Progression:

Answer 2

the ability to generate a rhythmic stepping pattern to move the body forward
initiate and terminate movement

Question 3

Postural Control:

Answer 3

the ability to ensure both orientation and stability

Question 4

Adaptability:

Answer 4

the ability to adapt gait to changing tasks and environmental requirements

Question 5

Progression for stance:

Answer 5

stabilizing limb for weight bearing and generating forces to move the body for continued motion

Question 6

Progression for swing phase:

Answer 6

advancement of the swing leg to reposition the limb (in preparation for weight acceptance), and make sure toes clear the ground

Question 7

Postural Control stance phase:

Answer 7

vertical forces support the body mass against gravity

Question 8

Postural Control swing phase:

Answer 8

repositioning of the limb in preparation for weight acceptance

Question 9

Adaptability stance phase:

Answer 9

changes in speed and direction or alterations (e.g., uneven terrain) in the support surface

Question 10

Adaptability swing phase:

Answer 10

avoidance of obstacles by swing foot

Question 11

Temporal parameters

Answer 11

Stance/swing time
Single-limb support time
Double-limb support time
Stride time
Step time
Cadence
Speed/Velocity

Question 12

Spatial parameters

Answer 12

Stride length
Step length
Step width
Toe-out angle

Question 13

Stance/swing time

Answer 13

time in stance/swing on a given limb

Question 14

Single-support time

Answer 14

time elapsed in which the body is supported by a single limb

Question 15

Double-support time

Answer 15

time elapsed in which both feet are in contact with the ground

Question 16

Stride duration

Answer 16

time required to complete one stride

Question 17

Step duration

Answer 17

time required to complete one step

Question 18

Velocity

Answer 18

rate of linear movement (meter/second in research vs. 40 feet or for 6 minutes in clinic)

Question 19

Cadence

Answer 19

(a frequency unit): the number of steps within a unit time, often denoted as steps/minute (e.g., 80 steps/min)

Question 20

Step length

Answer 20

distance between the contralateral foot strikes

Question 21

Stride length

Answer 21

distance from one foot strike to the next for the same (or ipsilateral) foot (~ twice the step length in normal gait).

Question 22

Step Width

Answer 22

linear distance between midpoint of the heel of ipsilateral and contralateral feet

Question 23

Degree of Toe-Out (DTO)

Answer 23

Angle of foot formed by each foot’s line of progression

Question 24

Components of stance:

Answer 24

initial contact
loading response
mid stance
terminal stance
preswing

Question 25

Components of swing:

Answer 25

initial swing mid swing terminal swing

Question 26

Functional tasks of gait:

Answer 26

weight acceptance single limb support swing limb advance

Question 27

Initial contact

Answer 27

0-2% | moment when leading limb touches floor

Question 28

Objectives of initial contact

Answer 28

Start stance with heel rocker | Impact deceleration

Question 29

Loading response

Answer 29

2-12% first period of double stance body weight to leading leg trailing leg in preswing

Question 30

Objectives of loading response:

Answer 30

shock attenuation, weight-bearing, forward progression

Question 31

Mid Stance

Answer 31

12-31% | first half of single limb stance

Question 32

When does mid stance begin?

Answer 32

toe off of trailing limb

Question 33

When does mid stance end?

Answer 33

Weight aligned over the leading/supporting limb

Question 34

Objectives of mid stance?

Answer 34

1) forward progression over the stationary foot; | 2) weight bearing (limb and trunk Stability)

Question 35

Terminal stance?

Answer 35

31-50%

Question 36

When does terminal stance begin?

Answer 36

Heel rise initiates second half of single-limb support

Question 37

When does terminal stance end?

Answer 37

Non-support limb (blue) strikes the ground

Question 38

Objectives of terminal stance?

Answer 38

(1) Progression of body beyond support limb (red); | 2) weight bearing (limb and trunk Stability

Question 39

Pre-swing:

Answer 39

50-62% A rapid unloading of the limb occurs as weight is transferred to the contralateral (lead) limb. Unweighting allows limb to prepare for swing

Question 40

When does pre-swing being?

Answer 40

Initial contact of contralateral (swing) limb

Question 41

When does pre-swing end?

Answer 41

Ipsilateral limb (support) toe off

Question 42

Objectives for pre-swing?

Answer 42

(1) Position the limb for swing phase, | (2) accelerate progression (propulsion)

Question 43

Initial swing:

Answer 43

62-75% Contralateral limb is in mid-stance Foot lifts from ground during first third of swing Advances to opposite stance foot.

Question 44

When does initial swing begin?

Answer 44

ipsilateral limb (red) leaves floor

Question 45

When does initial swing end?

Answer 45

ipsilateral is opposite stance foot

Question 46

Objectives of initial swing?

Answer 46

(1) Foot clearance of the floor, (2) advancement of the limb from its trailing position

Question 47

When is foot drop most evident?

Answer 47

initial swing

Question 48

Mid swing

Answer 48

75-87% Contralateral limb is in late mid-stance Limb advances during the middle third of the swing until tibia achieves vertical (i.e., hip and knee flexion postures are equal).

Question 49

When does mid swing begin?

Answer 49

end of initial swing

Question 50

When does mid swing end?

Answer 50

ipsilateral limb advances anterior of the body

Question 51

What are the objectives of mid swing?

Answer 51

(1) limb advancement, | (2) Foot clearance of the floor,

Question 52

Terminal swing

Answer 52

87-100% Tibia advances during final third of swing, and limb advancement is completed as the leg (shank) moves ahead of the thigh

Question 53

When does terminal swing begin?

Answer 53

end of mid-swing

Question 54

When does terminal swing end?

Answer 54

ipsilateral limb initial contact

Question 55

What are the goals of terminal swing?

Answer 55

(1) Complete limb advancement; | (2) Prepare for stance phase

Question 56

Ground force reaction:

Answer 56

Force applied back on the individual (Newton’s 3rd law)

Question 57

Goals of stance limb:

Answer 57

to support the body (postural control) and propel the body forward;

Question 58

Goals of swing limb:

Answer 58

foot clearance and limb advancement

Question 59

Muscle activation for loading response

Answer 59

hip: extensors knee: GFR posterior to knee; knee extensors contract ankle: GFR anterior to joint

Question 60

Muscle activation for mid stance

Answer 60

hip: plane abductors knee: GFR anterior to knee; mostly hamstrings ankle: PF eccentric

Question 61

Muscle activation for terminal stance:

Answer 61

hip: GFR posterior to joint; extension moment knee: initial flexor activity ankle: PF, gastroc, soleus, FDL, FHL

Question 62

Muscle activation preswing

Answer 62

hip: flexor activity knee: rectus femoris ankle: PF strong initially

Question 63

Muscle activation mid swing:

Answer 63

hip: flexors first, them extensors knee: flexor activity ankle: DF (toe clearance)

Question 64

Muscle activation for terminal swing:

Answer 64

hip: increasing extensor activity knee: flexors, then extensors to stabilize ankle: increasing DF at end of phase

Question 65

Highest point of vertical displacement of COM?

Answer 65

midstance

Question 66

Lowest point of vertical displacement of COM?

Answer 66

double support

Question 67

What is the average vertical displacement?

Answer 67

5 cm

Question 68

Lateral limit of COM?

Answer 68

mid stance