Mobility_PL

Question 1

List categories of mobility (4)

Answer 1

1. Walking/Gait
2. Transfers
3. Bed Mobility
4. Stair Walking

Question 2

List the 3 Essential Requirements for Successful Locomotion

Answer 2

1. Progression
2. Postural Control
3. Adaptation

Question 3

Term: the need to initiate and terminate locomotion and move the body in the desired direction

Answer 3

Progression

Question 4

Term: maintain the body upright and stable in a dynamic environment

Answer 4

Postural Control

Question 5

Term: alter gait in response to a dynamic environment and changing goals

Answer 5

Adaptation

Question 6

Describe the forces that need to be generated during stance (2)

Answer 6

1. horizontal forces to keep the body moving forward
2. vertical forces to support the body against gravity

Question 7

Describe what needs to be accomplished during swing (3)

Answer 7

• advance the swing limb
• position the swing limb so it’s ready to accept weight
• avoid contact with the ground/obstacles

Question 8

Describe the gait cycle

Answer 8

Symmetrical alternating gait pattern that provides the greatest dynamic stability with minimal control demands

There is a phase lag between limbs of a half cycle

Question 9

List the % time spent in stance vs. swing and single vs. double stance

Answer 9

60% stance; 40% swing

40% single stance; 20% double stance

Question 10

List the subphases of stance and swing

Answer 10

Stance: initial contact, loading, midstance, terminal stance, preswing

Swing: initial, mid, terminal

Question 11

List the temporal and distance factors affecting gait (4)

Answer 11

• velocity
• step length (can ID asymmetry)
• step frequency or cadence (steps/min)
• stride length (heelstrike to heelstrike on same foot)

Question 12

List the normal young adult speeds

1. Gait
2. Cadence
3. Step Length

Answer 12

1. 1.46 m/s
2. 1.9 steps/sec
3. 76.3 cm or 30.05 in

Question 13

Describe how gait velocity is selected

Answer 13

Step rate and gait velocity is related to trying to minimize energy output/energy expenditure

** Swing phase doesn’t require much EE in normal gait

Question 14

List 2 factors essential for normal gait

Answer 14

1. Sensory information from periphery
2. Descending control

Question 15

Describe reactive equilibrium control

Answer 15

This type of control is used in response to perturbation and involves the somatosensory, visual, and vestibular systems

vision: control of velocity; vertical alignment
vestibular: control of gaze, head stabilization
somatosensory: distal to proximal sequence w/slips

Question 16

Describe how the body responses to a slip in early vs. late swing

Answer 16

early: elevating strategy of swing limb by increased flexion of swing limb and early heel rise of stance limb
late: lowering strategy with PF of swing foot to reach the ground

Question 17

Describe proactive equilibirium control

Answer 17

This is the use of vision to identify and avoid or accommodate for obstacles. Predictions are made based on our past experiences.

simple terrain = visual sample 10% of the time

uneven terrain = visual sample 30% of the time

Question 18

Describe how gait is initiated (3)

Answer 18

• begins with relaxation of mm (gastroc/soleus) from quiet stance
• has appearance of falling forward
• shifts COP from toward swing limb and then to stance limb

Question 19

Describe the 2 turning strategies

Answer 19

1. spin-turn (turn to R, R foot forward, body spins around R foot)
2. step-trun (turn to L, R foot forward, weight shifted to R foot, L hip ER, weight transfers to L foot)

Question 20

Describe the differences between stair ascent and descent

Answer 20

Ascent: requires forces 2x of that needed in level walking, knee extensors generate the most energy to move forward, greatest instability with contralateral toe-off when the ipsilateral leg takes all BW and limb is flexed

Descent: eccentric contraction is key

Question 21

List 2 key components of adapting stair walking patterns

Answer 21

1. foot clearance
2. foot placement

**depend largely on visual input

Question 22

List the essential characteristics of moving from sitting to standing (3)

Answer 22

• Generating sufficient joint torque to rise
• Ensuring stability by moving COM from 1 BOS to BOS defined by feet
• Ability to modify movement strategy depending on environment

Question 23

Describe the 4 phases of the momentum transfers strategy to move from sit to stand

Answer 23

1. Weight Shift/Flexion Momentum: flex trunk, body stable, COM is moving within BOS of the chair seat
2. Beginning to lift: butt leaves seat, horiztonal and verticla motion must coordinated (unstable phase)
3. Lift/Extension: extension of hips/knees, most movement is vertical
4. Stabilization: body stability is achieved

Question 24

Describe the zero momentum strategy for moving from sit to stand (3)

Answer 24

• Flex trunk, put COM over feet
• Increased foce of LE to lift
• More stable throughout

Question 25

Describe the arm rest strategy for moving from sit to stand (3)

Answer 25

- Increased stability - Assists increased force generation requirements of zero-momentum strategy - No always feasible for pt.

Question 26

List the primary contributor to stable walking and major factor affecting loss of independing mobility in older adults

Answer 26

Primary contributor to stable walking = balance control Major factor affecting loss of independent mobility = decreased balance control

Question 27

Describe how proactive adpatation is altered in elderly individuals

Answer 27

Increased visual sampling, more variable step length, slower velocity, decreased stability

Question 28

List factors critical for recovery from a trip (2)

Answer 28

Quick reactions of: - hip flexors of swing leg - PF of stance leg

Question 29

Describe the gait changes in balance impaired older adults (2)

Answer 29

- decreased stride length and walking speed - increased stride time, step width, and variability

Question 30

List the pathologies that contribute to age related gait changes (5)

Answer 30

- standing balance - cognition - increased fear of falling - sensory impairments - mm weakness

Question 31

Describe age related changes to the following 1. gait initiation 2. stair walking 3. sit to stand

Answer 31

1. keep COP and COG more closely aligned to minimize unsteadiness 2. larger foot clearance with descent 3. increased trunk flexion, higher movement velocity, lower forces, increased time to rise