Gait

Question 1

How much time is spent in stance vs swing phase.

Answer 1

Stance phase 60%

Swing phase 40%

Question 2

What part of the gait cycle marks the end of stance phase and the beginning of swing phase?

Answer 2

Pre swing/Toe off.

Question 3

Which are the 5 phases of stance phase?

Answer 3

Initial contact
Loading response
Mid stance
Terminal stance
Pre swing

Question 4

Which are the 3 phases of swing phase?

Answer 4

Initial swing
Mid swing
Terminal swing

Question 5

In which 2 phases of stance phase does initial double support occur?

Answer 5

Initial contact

Loading response

Question 6

In which 2 phases of stance phase does single support occur?

Answer 6

Mid stance

Terminal stance

Question 7

In which part of stance phase does terminal double support occur?

Answer 7

Pre swing

Question 8

Describe the primary functional goal of ambulation?

Answer 8

Maintain an upright position while enabling progression from one limb to the next.

Question 9

Forward progression is divided into how many rockers? And which are they?

Answer 9

Four rockers.

Heel rocker
Ankle rocker
Forefoot rocker
Toe rocker

Question 10

Describe the heel rocker…

Answer 10

Heel rocker involves the heel serving as a pivot point for the foot to move from a neutral position at initial contact toward 10 degrees of plantarflexion during loading response. The pivoting action translates momentum generated during weight acceptance to initiate forward progression of the tibia.

Question 11

Describe the ankle rocker…

Answer 11

Ankle rocker occurs at the onset of midstance as the pivot point moves from the heel to the ankle. During midstance, the tibia and more proximal aspect of the limb rotate forward at the ankle along the line of progression. This allows advancement of the stance limb and the body.

Question 12

Describe the forefoot rocker…

Answer 12

Forefoot rocker occurs as the limb moves into terminal stance as the heel comes off the ground and the pivot point shifts to the forefoot and the rounded contour of the metatarsal heads. The action of the forefoot rocker accelerates forward progression as the body weight falls beyond the area of foot support.

Question 13

Describe the toe rocker…

Answer 13

Toe rocker takes place during preswing as the toe serves as the final pivot point for the body’s continued forward movement and transition into swing phase.

Question 14

Name the 6 determinants of gait.

Answer 14

1. Pelvic rotation in the horizontal plane
2. Pelvic tilt in the frontal plane
3. Knee flexion
4. and 5. Foot and ankle motion
5. Lateral displacement of the pelvis

Question 15

Describe pelvic rotation as one of the determinants of gait.

Answer 15

Pelvic rotation involves forward angular rotation of the pelvis in the transverse plane of approximately 5 degrees. This motion effectively increases the length of the lower limbs and reduces downward displacement of the CoG.

Question 16

Describe knee flexion as one of the determinants of gait.

Answer 16

Knee flexion to about 15-20 degrees occurs during loading response. This motion is followed by extension of the limb to about 5 degrees short of full extension in mid-stance. The knee flexion provides shock absorption and limits vertical displacement of the CoG that would otherwise occur with full extension of the lower limb.

Question 17

Describe foot and ankle motion as one of the determinants of gait.

Answer 17

Foot and ankle motion focus on ankle plantarflexion after initial contact and during terminal stance. Plantarflexion early in stance allows the foot to assume a foot-flat position and decreases the rise in CoG. Plantarflexion late in stance allows the heel to rise and prevents rapid tibial progression from provoking a sudden drop in the CoG.

Question 18

Explain stride length.

Answer 18

Occurs between initial contact of a limb and the subsequent initial contact of the same limb.

Question 19

How long is the approximate stride length.

Answer 19

1.4m

Question 20

How long is step length?

Answer 20

Approximately 70cm.

Question 21

Describe a step.

Answer 21

Initial contact of a limb to initial contact of the contralateral limb.

Question 22

What is average step width?

Answer 22

8-10cm.

Question 23

What is cadence?

Answer 23

Cadence is the number of steps taken in a given period. Cadence averages 90 to 120 steps per minute in adults walking at a comfortable speed.

Question 24

How fast is normal self selected walking speed?

Answer 24

Normal comfortable self-selected walking velocity averages 1.34 m/s.

Question 25

What is the plantar flexion at loading response and at pre swing?

Answer 25

10 degrees at loading response

20 degrees at pre swing

Question 26

Describe knee range of motion during stance phase?

Answer 26

5 degrees of flexion at initial contact

10-15 degrees at loading response

-5 degrees at full extension

Max 60 degrees at mid swing

Question 27

Describe hip range of motion during gait.

Answer 27

30 flexion at initial contact

Max extension of 10degrees at terminal stance.

30 degrees of flexion during swing just before initial contact

Question 28

Describe the grfv during gait.

Answer 28

Ground reaction force vector during gait. The magnitude and location of the ground reaction force vector in relation to the joints of the lower limb change during the stance phase of gait.

Question 29

Read kinetics at the ankle.

Answer 29

Ankle.
The ground reaction force (GRF) is initially located posterior to the ankle at initial contact, creating a plantarflexion moment. During the loading response, the plantarflexion moment continues at the ankle, and ankle dorsiflexors must resist this torque to prevent foot drop. During midstance, the GRF moves anteriorly, so a strong dorsiflexion moment at the ankle is produced in terminal stance. This dorsiflexion moment is opposed by the ankle plantar flexors to limit forward progression of the tibia. In preswing, a dorsiflexion moment remains at the ankle. Thus ankle plantarflexion motion is created by concentric contraction of the ankle plantar flexors, and this helps to propel the stance limb forward.

Question 30

Read kinetics at the knee.

Answer 30

Knee.
At initial contact, the GRF is normally located anterior to the knee, but the GRF quickly moves posterior to the knee during the loading response. A flexion moment is the result, and knee extensors counter this moment to keep the knee from collapsing. The knee flexion moment remains in place until terminal stance, at which time the GRF moves back anterior to the knee. At the end of preswing, just before the foot leaves the ground, the GRF moves posterior to the knee. This produces a knee flexion moment and helps initiate a period of rapid knee flexion in preparation for the swing phase of gait.

Question 31

Read kinetics at the hip.

Answer 31

Hip.
The GRF is initially anterior to the hip joint center. As such, a flexion moment is present at the hip at initial contact and during the loading response. During midstance, as the tibia rotates forward, the hip moves anterior to the GRF, creating an extension moment. This extension torque across the hip remains in place throughout the remainder of stance phase, and activation of the hip flexors is required to overcome this moment in late stance to initiate hip flexion.

Question 32

During gait what muscle contractions are typically used to generate motion.

Answer 32

Concentric.

Question 33

During gait what muscle contractions are typically used to decelerate motion.

Answer 33

Eccentric.

Question 34

Describe muscle function of Ankle dorsiflexors in early stance phase

Answer 34

Eccentric contraction to control ankle plantarflexion in loading response

Question 35

Describe muscle function of Ankle dorsiflexors in swing phase

Answer 35

Concentric contraction for ankle dorsiflexion and to facilitate foot clearance during swing phase

Question 36

Describe muscle function of Ankle plantar flexors during Midstance phase:

Answer 36

Eccentric contraction to control the ankle dorsiflexion moment and prevent excessive forward tibia rotation

Question 37

Describe muscle function of knee extensors during initial contact and loading response:

Answer 37

Eccentric contraction to control knee flexion and prevent knee buckling

Question 38

Describe muscle function of knee extensors during Late stance and early swing phase:

Answer 38

Eccentric contraction to control collapse of the knee and prevent early heel rise

Question 39

Describe muscle function of Knee flexors
During Early and midswing phase:

Answer 39

Concentric contraction in swing phase to produce knee flexion and facilitate foot clearance in swing phase

Question 40

Describe muscle function of knee flexors during Late swing phase and early stance phase:

Answer 40

Eccentric and isometric contraction to control knee extension and stabilize the limb before weight bearing.

Question 41

Describe muscle function of Hip extensors during Late swing:

Answer 41

Concentric contraction to rotate the thigh posteriorly and to stabilize the limb in preparation for weight bearing in stance phase

Question 42

Describe muscle function of hip extensors during Early stance:

Answer 42

Concentric or isometric contraction to control hip and knee flexion and stabilize the limb

Question 43

Describe muscle function of hip flexors during Late stance phase:

Answer 43

Eccentric contraction to slow and control posterior rotation (extension) of the thigh

Question 44

Describe muscle function of hip flexors during Swing phase

Answer 44

Concentric contraction to initiate hip flexion and accelerate the swing limb forward

Question 45

Which motor neuron involvement usually presents with typically associated with impaired motor control, elevated muscle tone, and hyperreflexia?

Answer 45

Upper motor neuron.

Question 46

Which motor neuron involvement is commonly associated with decreased muscle tone and decreased reflexes.

Answer 46

Lower motor neuron.

Question 47

How can hypertonicity prove useful?

Answer 47

Hypertonicity can mask the extent of true muscle weakness such that the person with profound weakness, but elevated muscle tone, may still be able to stand and ambulate because of the elevated tone.

Question 48

What are the three basic levels of primitive control?

Answer 48

Locomotor synergies, postural reflexes, and stretch reflexes.

Question 49

Which process can become active when selective control of muscles is impaired by an upper motor neuron process?

Answer 49

Primitive control mechanisms.

Question 50

In primitive control, Locomotor synergies provide which two patterns of muscle action?

Answer 50

An extensor pattern simultaneously activates the hip and knee extensors and the ankle plantar flexors.

The flexion pattern activates the ankle dorsiflexors in concert with the hip and knee flexor muscles.

Question 51

In postural reflexes, how does a straight knee increase tone? And what a bout flexed knee?

Answer 51

Straight:
In all of the extensor muscles, including the ankle plantar flexors.

Flexed:
Conversely, limb flexion relaxes the extensors and augments the flexors.

Question 52

On postural reflexes, hows does being upright affect tone?

Answer 52

Being upright increases extensor tone compared with lying supine.

Question 53

In primitive control, during stretch reflexes, what is usually produced by a quick stretch?

Answer 53

Clonus.

Question 54

Define a steppage or high steppage gait

Answer 54

Drop foot with excessive knee and hip flexion in swing phase to compensate for poor toe clearance. Foot slap and limited knee flexion at loading response.

Question 55

Describe the gait observation of a person with plantarflexion weakness and unrestricted ankle dorsiflexion ROM:

Answer 55

Increased knee flexion in midstance to late stance phases. During the preswing phase, heel rise is either delayed or absent, and there is limited push-off with the affected limb. The secondary effect is persistent or excessive knee flexion. Consequently, contralateral swing phase and step length are shortened.

Question 56

Which part of the gait cycle does plantar flexion weakness affect?

Answer 56

Stance phase. Ankle plantar flexors muscles are inactive in swing phase.

Eccentric loading at midstance to control tibial progression and eccentric loading for forward propulsion.

Question 57

What can knee weakness lead to.

Answer 57

Knee weakness can lead to excessive flexion or hyperextension and be a result of upper and lower neuron conditions.

Question 58

Regarding knee weakness, in the case of an upper motor neuron involvement, what type of tone pattern is usually associated?

Answer 58

Extensor tone pattern. Excessive plantar flexion and knee extension.

Question 59

Give an example of how instability of the knee can be created by ankle weakness or ankle ROM limitations.

Answer 59

Ankle plantarflexion contracture that results in a GRF being maintained anterior to the knee and creating a subsequent prolonged extension moment at the knee during the early stance phase of gait.