Gait Flashcards
(55 cards)
1
Q
Gait cycle
A
60% stance, 40% swing
- initial and terminal 10% double stance
- middle 40% single limb stance
2
Q
Functional elements of gait cycle
A
- Progression
- Standing stability
- Energy conservation
3
Q
Progression
A
Forces
- Forward fall of the body weight (begins in single limb stance as ankle DF and accelerates with heel rise)
- Generated by the conralateral swinging limb (starts with onset of single limb stance). This is important before body is aligned for an effective forward fall
4
Q
Standing stability
A
- balance challenged by weight displacement (top-heavy) and walking continually alters segment alignment
- two functional units (passenger and locomotor)
- ever-changing alignment of body weight is stabilized by selective muscular control
- timing and intensity of each mm’s activity are dictated by the relationship of body weight to the center of the joint that mm controls
- selective neural control and proprioception as well as adequate mm response
5
Q
Passenger unit
A
Head, arms, and trunk
- there are carried rather than contributing to the act of walking
- arm swing is passive reaction to monetum
6
Q
Locomotor unit
A
Two limbs joined by intervening pelvis
- pelvis is both locomotor and passenger with two highly mobile junction points (L/S and hip joints)
7
Q
Energy conservation
A
- Optimum use of momentum occurs during the person’s natural gait velocity. This pattern requires the lease energy expenditure per meter travelled
- faster or slower pace = increased energy cost - Minimization of body displacement from the line of progression
- accomplished by coordinating pelvic, knee, and ankle motion to keep limb length fairly constant throughout stance
8
Q
Ankle ROM for gait
A
- 20 degrees PF (terminal stance to toe-off)
- 10 degrees DF (mid to terminal stance)
9
Q
Knee ROM for gait
A
- 60 degrees of flexion (swing)
- 0 degrees of ext (heel strike and midstance)
10
Q
Hip ROM for gait
A
- 30 degrees of flex (swing phase)
- 10 degrees of ext (terminal stance)
11
Q
Initial contact
A
Heel strike (double limb support)
- begins when heel contacts ground
- ends at beginning of loading response
- torques: ankle PF, knee ext, and hip flex
12
Q
Initial contact joint motion
A
- hip: 30 degree flex
- knee: 0 degree
- ankle: neutral
- pelvic rotation: forward on step side
13
Q
Initial contact peak torque mm
A
- glute max: eccentric (hip position determines angle between foot and floor)
- quads: eccentric
- Pretibial mm: tib anterior, long extensors of the great and common toes, peroneus tertius
14
Q
Loading response
A
Foot flat (double limb support)
- begins when weight shifted on to the limb and entire foot makes contact w/ ground
- ends within opposite foot leaves the ground
- heel rocker!
- goal is acceptance of body weight to ensure limb stability and still permit progression
15
Q
Heel rocker
A
- strong action by pretibial mm slows the terminal arc of ankle PF, so forefoot contact is gradual
- first 6-8% of gait cycle
- initiates knee flex
16
Q
Loading response joint motion
A
- hip: 30 degrees flex moving into ext
- knee: 15-20 degrees flex
- ankle: 15 degrees PF
- pelvic rotation: forward
17
Q
Loading response peak torque mm
A
- tibialis anterior: eccentric
- quads - biceps femoris - glute max and adductor magnus (restrain hip flex)
18
Q
Midstance
A
Single limb support
- begins when opposite foot leaves the ground
- ends when body is directly over WB limb
- goal is advancement of the body and limb over a stationary foot
- requires total contact of foot (heel, 1st and 5 metatarsal heads)
- ankle rocker!
19
Q
Ankle rocker
A
Allows progression to continue
- occurs due to residual momentum and contralateral swinging limb
20
Q
Midstance joint motion
A
- hip: ext toward neutral
- knee: 0 degrees
- ankle: 10 degrees dorsiflexion
- pelvic rotation: neutral
21
Q
Midstance peak torque mm
A
- quads (early phase)
- glute med: concentric
- gastro/soleus: eccentric
- peroneals / post tibialis stabilize ankle
22
Q
Midstance ankle
A
5 degrees of PF to 5 degrees of DF, with 10 degrees of DF being attained just as the heel rises to initiate terminal stance
- tibia is allowed to advance beyond the neutral position
- soleus responds by restraining tibia’s progression w/ assistance from gastroc
- available range and timely tibial restraint are the critical events for midstance
23
Q
Midstance knee
A
Knee flexion is induced during the loading response and reaches its max of 18 degrees just as single-limb support is initiated
- motion of knee then reverses to progressive ext
- at middle of midstance, body vector moves anterior to joint center, and an extensor moment is begun (quad relaxes)
- need for active mm control is terminated
- quad action is maximal at the onset of midstance and progressively declines as knee extends over the vertical tibia
24
Q
Midstance hip
A
Progressive decline in hip flex and entry into ext allow trunk to remain erect while limb becomes more vertical (passive)
- onset of single stance = quick hip add in the stance limb limited to 4 degrees of hip add and then reversed by active abd
- hip add mm activity is intense through midstance while extensors are quiet
25
Terminal stance
Heel off (double limb)
- begins as heel of WB limb rises
- ends at initial contact of opposite foot
- goal is to forward fall to generate a propulsive force (ankle and foot are critical sites of action)
26
Terminal stance joint motion
- hip: 10 degrees ext
- knee: 0 degrees
- ankle: 10 degrees DF to 5 degrees PF
- pelvic rot: posterior
27
Terminal stance peak mm
**gastroc/soleus: concentric
28
Terminal stance ankle
At onset, DF drops into 10 degrees DF (max ROM necessary for gait), then reverses to 5 degrees PF by end of single limb support
- need stabilization in a neutral position for forefoot to act as propulsive rocker
- soleus and gastro restrain DF torque and then ceases abruptly as single stance period is terminated
29
Terminal stance foot
Stability at forefoot is gained by inversion, this locks all the midfoot joints (transverse tarsal, intercuneiform, cuneiform-cuboid, and metatarsal bases)
- at the end of terminal stance, MP joint DF approx 20 degrees
- mm active: long and short toe flexors (arch support and passive plantar fascia), all foot and toe mm, tibialis posterior and soleus (to preserve inversion), peroneals (to restrain inversion)
30
Terminal stance knee
Forward alignment of body weight passively extends knee - starts to flex at end of terminal stance
- mm active: NO quad action at this time as knee ext stability is gained from body vector being anterior to knee joint axis
- max ext = 0-5 degrees
31
Terminal stance hip
Passive ext of the hip joint
- anterior joint structures are maximally stretched
- as body weight falls toward other limb, passive hip abd is induced
- max hip ext = 10 degrees
- mm active: iliacus (restrain hip ext) NO hip extensor activity
32
Preswing
Toe off (double limb)
- begins with initial contact of opposite leg and when weight is shifted onto opposite leg
- ends just before the toes of WB limb leave the ground
- goal: preparation of the limb for swing/limb advancement
* *knee response is key
33
Preswing joint motion
- hip: neutral
- knee: 40 degrees flex
- ankle: 20 degrees PF
- pelvic rotation: posterior
34
Preswing torque mm
(Iliacus)
***passive motion
35
Preswing knee
Rapid passive flex to 40 degree flex
| - NO flex mm action
36
Preswing hip
Flex of hip from 10 degrees of ext to neutral
| - iliacus and rectus femoris
37
Preswing ankle/foot
Rapid ankle PF to 20 degrees (passive)
| - flexor hallucinate longus (sustains MP joint compression and restrains DF while floor contact is maintained)
38
Initial swing
Acceleration (single limb support)
- begins when toes leave the ground
- end whenswing foot is opposite the WB foot and the knee is in max flex
- goal: recovery from a trailing posture
* *flex of hip and knee
39
Initial swing joint motion
- hip: 20 degrees flex
- knee: 60 degrees flex
- ankle: 10-0 degrees PF
- pelvic rotation: posterior
40
Initial swing peak torque mm
(Tibialis anterior, long toe extensors, hammies, biceps femoris long head)
41
Initial swing hip
Rapidly flexes from neutral to 20 degrees of hip flex
| - iliacus (main force advancing the thigh), sartorious, gracious, and adductor longus
42
Initial swing knee
Flex increases from 40-60 degrees
| - short head of the biceps femoris, sartorious, gracilis
43
Initial swing ankle
DF is initiated, however, ankle is still in 10 degrees of PF by end of initial swing
- tibialis anterior, long toe extensors, peroneus tertius
44
Mid swing
(Single limb support)
- begins when swing foot is opposite WB foot
- ends when swing leg is in front of body w/ tibia vertical to ground
- goal: limb advancement continues (tibial alignment makes foot control critical for foot clearance)
45
Midswing joint motion
- hip: 30 degrees flex
- knee: 30 degrees flex
- ankle: neutral
- pelvic rotation: neutral
46
Midswing peak torque mm
(Iliacus)
| - tibialis anterior: concentric
47
Midswing hip
Max hip flex reached (iliacus)
48
Midswing knee
Extends passively for acceleration advancement of the leg and foot
- flexor mm RELAXED
49
Midswing ankle
DF to neutral and then maintained
| - tibialis anterior and other pretib mm (active control of foot)
50
Terminal swing
Deceleration (single limb)
- begins when tibia is vertical to ground
- ends just prior to initial contact
- goal: limb advancement ceases and limb is prepared for stance
* **complete knee ext
51
Terminal swing joint motion
- hip: 30 degrees flex
- knee: 0 degrees
- ankle: neutral
- pelvic rotation: forward
52
Terminal swing peak torque mm
*hammies: eccentric
*anterior tibialis: concentric
(Quads)
53
Terminal swing hip
Maintain 30 degrees of flex
| - semimembranosus, semitendinosus, biceps femoris long head (all have peak activity and prevent further motion)
54
Terminal swing knee
Ext to neutral
| - quads (active ext), hamstrings (decelerate hip flexion and prevent hyperext of knee)
55
Terminal swing ankle
Continued neutral DF, but foot may drop into 3-5 degrees of PF by end of phase
- pretib mm (though decreases intensity as phase progresses)
