Biomechanics - Gait Analysis 1

Question 1

What is gait?

Answer 1

The name used to describe bipedal locomotion.

Question 2

Bipedal locomotion?

Answer 2

The form of movement used by humans when they walk or run.

Question 3

There are a number of general principles of gait, but…

Answer 3

many subtle individual variations.

Question 4

Walking gait is more or less…

Answer 4

symmetrical.

Question 5

One gait cycle? What is it known as?

Answer 5

Occurrence of an event, such as a heel-strike or toe-off, to the next occurrence of that event for the same event for the same leg.
Known as a stride.

Question 6

A step?

Answer 6

An occurrence of an event to the next occurrence of that. event for the opposing leg.

Question 7

What 2 phases is walking gait divided into?

Answer 7

Stance and swing phases.

Question 8

Stance phase is typically what % of walking stride? What does it vary little with?

Answer 8

60% of walking stride (one gait cycle).

Varies little with speed.

Question 9

What does walking contain a period of?

Answer 9

Double support.

Question 10

4 phases of walking?

Answer 10

1. ) Foot flat.
2. ) Midstance.
3. ) Terminal stance.
4. ) Pre-swing.

Question 11

3 phases of swinging?

Answer 11

1. ) Initial swing.
2. ) Midswing.
3. ) Terminal swing.

Question 12

Foot flat?

Answer 12

When one of your feet is flat on the ground whilst walking.

Question 13

Midstance?

Answer 13

When one of your feet is flat and the opposite leg is about to rise whilst walking.

Question 14

Terminal stance?

Answer 14

When one of your feet is making a toe-off motion and the opposite leg is about to reach the ground whilst walking.

Question 15

Pre-swing?

Answer 15

When neither foot is flat but both are touching the ground whilst walking.

Question 16

What does walking speed derive from? Units?

Answer 16

Stride length (m).
Stride rate (Hz).

Question 17

When do the ground reaction forces = 0 in walking?

Answer 17

During the pre-swing phase.

Question 18

How do the elderly walk unless they have diseases such as osteoporosis with kyphosis?

Answer 18

Upright with no forward lean.

Question 19

Osteoporosis? Kyphosis?

Answer 19

Health condition that weakens bones, making them more fragile.
Rounding of the upper back.

Question 20

Why do elderly people walk with about 5 degrees greater abduction (toe out)?

Answer 20

Possibly due to a loss of hip internal rotation or to increase stability.

Question 21

What is unaffected in the elderly in relation to walking gait?

Answer 21

Ground clearance as the foot swings.

Cadence (rhythm) does not change with age.

Question 22

How does walking gait velocity change in the elderly?

Answer 22

Remains stable until around 70, and then falls about 15% per decade for normal gait.

Question 23

In the elderly, why is velocity lowered?

Answer 23

Shorter stride length.

Question 24

Why do the elderly have a shorter stride length?

Answer 24

Calf muscles are weaker and cannot produce sufficient plantar flexion.
May be reluctant to generate plantar flexion power because of poor balance and poor control of the centre of mass.

Question 25

What does preferred cadence relate to?

Answer 25

Leg-length.

Question 26

What does preferred cadence usually represent?

Answer 26

Energy-efficient rhythm for individual body structure.

Question 27

Do tall or short people take longer steps at a slower cadence?

Answer 27

Tall people.

Question 28

Do tall or short people take shorter steps at a faster cadence?

Answer 28

Short people.

Question 29

Double stance is what % of the gait cycle in young adults? Elderly people?

Answer 29

``` 18% = young adults. 26% = elderly people. ```

Question 30

Double stance?

Answer 30

Centre of mass is between the feet, which is a stable position.

Question 31

How does increased time in double stance in the elderly affect walking gait?

Answer 31

Reduces momentum. | Reduces time for the swing leg to advance, reducing step length.

Question 32

When may an increased double stance be needed?

Answer 32

On uneven ground or when balanced is impaired.

Question 33

What do elderly people with a fear of falling typically do?

Answer 33

Increase their double stance time.

Question 34

What is compromised for stability on uneven ground/when balanced is impaired?

Answer 34

Step length.

Question 35

What specific joint motions change with age in relation to walking gait?

Answer 35

Ankle plantar flexion is reduced during the late stage of stance, just before the back foot lifts off. Maximal ankle dorsiflexion is not reduced.

Question 36

Dorsiflexion?

Answer 36

Toes point towards the knee.

Question 37

Plantar flexion?

Answer 37

Toes point away from the knee.

Question 38

Via what principles is running gait similar to walking gait?

Answer 38

Approximately symmetrical. Stride & step definition. Stance and swing phases are evident. Relatively constant with speed.

Question 39

What is the key difference of running gait compared to walking gait?

Answer 39

Contains no double support and has no period of no support.

Question 40

What % does stance approximately make up of running stride?

Answer 40

30%.