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Flashcards in Gait Cycle Deck (47)
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1
Q

Is this force advantage/ disadvantage? If the fulcrum is closer to the effort?

A

force disadvantage

2
Q

Is this force advantage/ disadvantage? If the fulcrum is closer to the load?

A

force advantage

3
Q

Which class of lever is force advantage? force disadvantage?

A
force advantage= 2nd class lever 
force disadvantage= 3rd class lever
4
Q

give an example of a 1st class lever.

A

Ex. joint between head and 1st vertebrae

Ex. scissors, pliers, see-saw

5
Q

give an example of a 2nd class lever.

A

Ex. wheelbarrow, stapler, bottle opener, nutcracker

Ex. standing on tiptoes

6
Q

give an example of a 3rd class lever

A

Ex. biceps curl

Ex. fishing rod, tweezers, tongs

7
Q

What is Newton’s 1st law of motion?

A

(law of inertia)
a particle at rest , or moving in a straight line with a constant velocity, will remain in its state provided it is not subjected to an unbalanced force

8
Q

what is Newton’s 2nd law of motion?

A

(law of acceleration)
a particle acted upon by an unbalanced force experiences an acceleration that has the same direction as the force and a magnitude that is directly proportional to the force ; (F=ma)

9
Q

what is Newton’s 3rd law of motion?

A

(law of action-reaction)

the mutual forces of action and reaction between two particles/bodies are equal, opposite, and co-linear.

10
Q

explain this mechanical analysis method: direct dynamics (forward mechanics).

A

mechanical analysis of a system that determines movement from forces
Ex. using force plates to record forces

11
Q

explain this mechanical analysis method: inverse dynamics.

A

mechanical analysis of a system that determines force from movement
Ex. using video-based motion analysis

12
Q

what is the frontal plane movement for ankle, knee, and hip during the gait cycle?

A

ankle- inversion
knee- valgus
hip- abduction

13
Q

what percentage of the gait cycle is spent in stance phase?

A

60%

14
Q

what percentage of the gait cycle is spent in swing phase?

A

40%

15
Q

what percentage of the gait cycle is spent in double support? and when?

A

20% - there are 2 periods: 0-10% and 50-60%

16
Q

what percentage of the gait cycle then is spent in single-support?

A

80%

17
Q

what is normal gait speed?

A

1.4 m/s (3mph)

18
Q

what is normal step rate?

A
  1. 9 steps/s (110 steps/min)
19
Q

what is normal step length?

A

72 cm (28 inches)

20
Q

what is the term for the sequence of events taking place between successive heel contact of the SAME foot?

A

stride (or gait cycle)

21
Q

what is the term for the sequence of events that occurs with successive heel contacts of the OPPOSITE foot?

A

step

22
Q

what is stride length?

A

distance btwn two successive heel contacts of the SAME foot

23
Q

what is step length?

A

the distance btwn two successive heel contacts of DIFFERENT feet
*recall that normal step length is 72 cm (28 in)

24
Q

what is step width?

A

lateral distance btwn the heel centers of 2 consecutive foot contacts
*normal step width is 7-9cm

25
Q

what is foot angle?

A

“the degree of turnout”; the angle between the line of progression of the body and the long axis of the foot
*normal foot angle is about 7 degrees

26
Q

name the temporal descriptors of gait.

A

cadence (or step rate)
stride time
step time

27
Q

what is cadence?

A

of steps per minute

28
Q

what is stride time?

A

the time for a full gait cycle

29
Q

what is step time?

A

the time for completion of a right or left step

30
Q

of all the spatial and temporal measures of gait, what is the best measure of an individual’s walking ability?

A

walking speed

31
Q

all measurements of gait depend on what?

A

walking speed

32
Q

what are 2 strategies to increase walking speed?

A
  1. increasing stride or step length

2. increasing cadence

33
Q

which part of the gait cycle is affected when gait speed increases?

A

double-limb support (time spent in this phase will DECREASE)

34
Q

what happens to % of gait cycle spent in double limb support as gait speed increases?

A

% of gait cycle spent in double-limb support DECREASES

35
Q

what happens to stride length in the elderly?

A

stride length decreases

36
Q

what happens to stride length with increased speed?

A

stride length increases

37
Q

what happens to double support time with increased speed?

A

decreased double support time

38
Q

what happens to double support time in the elderly or in patients with balance disorders?

A

double support time increases

39
Q

what is considered slow speed/cadence?

A

<70 steps/min

40
Q

what is consdiered fast speed/cadence?

A

> 120 steps/min

41
Q

what is typical/comfortable speed?

A

80-110 steps/min

42
Q

what are the 2 reduction of energy mechanisms to reduce vertical excursion by limiting downward displacement of CoM?

A
  1. horizontal plane pelvic motion

2. sagittal plane ankle motion

43
Q

what are the 2 reduction of energy mechanisms to reduce vertical excursion by limiting upward displacement of CoM?

A
  1. stance phase knee flexion

2. frontal plane pelvic rotation

44
Q

what is the mechanism that reduces medial-lateral excursion to save energy?

A

frontal plane hip rotation- reducing step width

45
Q

How do women compare to men in terms of walking speed, step length, and cadence?

A

women exhibit a slower walking speed, shorter step length, and faster cadence than men.

46
Q

When is minimum and maximum kinetic energy reached in the gait cycle?

A

min. KE is reached at mid-stance for both legs (30% and 80% of gait cycle )
max. KE is reached at double-limb support (5% and 55%)

47
Q

when is minimum and maximum potential energy reached in the gait cycle?

A

min. PE is reached at double-limb support (5% and 55%)

max. PE is achieved when CoM reaches its highest points (30 and 80%)