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Flashcards in Gait Muscles Deck (54)
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1
Q

What are foot forces?

A

Force applied to the ground by the foot

2
Q

What are ground reaction forces (GRF)?

A

Forces applied to the foot by the ground

3
Q

T/F Foot forces and GRF are equal in magnitude in the same direction

A

False equal in magnitude but in opposite directions

4
Q

What is the center of pressure?

A

Point where the GRF acts on the foot

5
Q

EX: is GRF travels posterior to ankle it will create what type of external torque? What internal torque must we counter with?

A
External = plantar flexion
Internal = dorsi
6
Q

How can internal torque be created?

A

o Primarily created by muscle activation (lig, joint capsule, tendons will also assist)
o Passive internal structures

7
Q

When there is concentric muscle activation, what is occurring at joint?
What are 2 goals of concentric muscle activation?

A

internal torque is moving the joint in the direction of the muscle’s action
Goal:
o Stability
o Produce movement of a segment

8
Q

When there is eccentric muscle activation, what is occurring at joint?
What are 2 goals of eccentric muscle activation?

A

internal torque is moving the joint in the direction opposite of the muscle’s action
Goals:
o Shock absorption
o Decelerating a limb segment

9
Q

When a muscle is peaking during gait, what does that mean?

A

exhibit the most electrical activity or greatest contraction

10
Q

When a patient has muscular dysfunction, GRFV will not change, but what will?

A

Patient’s ability to counter it - can lead to altered gait patterns and compensations

11
Q

Goal of muscle activation at IC in sagittal plane?

A

stop leg from buckling and prepare for weight acceptance

12
Q

Describe what is happening at hip/knee/ankle muscle activation in sagittal plane at the IC phase of gait?

A
  1. Hip - ALL Hip extensors contract concentrically to prepare for LR
  2. Knee
    o Eccentric hamstring contraction to counteract extension torque
    o Knee extensors transition from concentric to eccentric contraction in preparation for loading response
  3. Ankle (plantar flexor moment) - Pretibials (tib ant, long toe extensors) contract concentrically
13
Q

What critical events happening during LR phase?

A
  1. Hip stability
  2. controlled knee flexion for shock absorption
  3. ankle plantar flexion
14
Q

Describe what is happening at hip/knee/ankle muscle activation in sagittal plane at the LR phase of gait?

A
  1. Hip - Concentric contraction of hip extensors (Gmax, Adductor Magnus, TFL, GMed peak)
  2. Knee - Eccentric contraction (shock absorption) of knee extensors (Quadriceps activity peaks)
  3. Ankle - Eccentric contraction (slow down) of ankle dorsiflexors (Tibialis anterior peaks)
    o Transition to eccentric contraction of ankle plantarflexors in late LR
15
Q

What critical event is happening during MSt phase?

A

controlled tibial advancement

16
Q

Describe what is happening at hip/knee/ankle muscle activation in sagittal plane at the MSt phase of gait?

A
  1. Hip - No hip muscular activity required in sagittal plane
  2. Knee - Quads eccentric to no activity
  3. Ankle - Eccentric contraction of gastroc/soleus
17
Q

What critical event is happening during TSt phase?

A

controlled ankle dorsiflexion with heal rise

18
Q

Describe what is happening at hip/knee/ankle muscle activation in sagittal plane at the TSt phase of gait?

A
  1. Hip - Minimal activity in sagittal plane
  2. Knee - No quad or HS activity
    (Tibial position maintained by gastroc)
  3. Ankle - Concentric contraction of ankle plantarflexors to prevent tibial collapse with heel rise
    (Gastroc/soleus activity peaks)
19
Q

What critical events occur with PSw phase?

A
  1. passive knee flexion to about 40
  2. ankle plantar flexion
  3. mtp extension of about 60
20
Q

Describe what is happening at hip/knee/ankle muscle activation in sagittal plane at the PSw phase of gait?

A
  1. Hip - Concentric contraction of hip flexors (Adductor longus peaks)
  2. Knee - Knee flexion is mainly passive (Slight concentric contraction of knee flexors and eccentric rectus (help thigh moving forward))
  3. Ankle - Ankle plantarflexor activity ceases in early preswing and passive tension contributes to ankle moving into plantar flexion
    o Ankle dorsiflexor concentric contraction initiated at the end of PSw
21
Q

What critical events occur with ISw phase?

A
  1. hip flexion to about 15

2. full knee flexion to 60 so we can clear foot

22
Q

T/F there is no ground reaction forces to match in ISw phase

A

True, because limb is in air

23
Q

Describe what is happening at hip/knee/ankle muscle activation in sagittal plane at the ISw phase of gait?

A
  1. Hip - Continued concentric contraction of hip flexors
    (Iliacus peaks)
  2. Knee - Concentric contraction of knee flexors
    (Biceps femoris (SH), sartorius, gracilis peak)
    o Flexion continues to be aided by flexion at the hip
  3. Ankle - Concentric contraction of tib anterior (Toe extensor activity peaks)
24
Q

What critical events occur at MSw phase?

A
  1. further hip flexion

2. ankle dorsi to 0 to clear foot

25
Q

Describe what is happening at hip/knee/ankle muscle activation in sagittal plane at the MSw phase of gait?

A
  1. Hip
    o Continued concentric contraction of hip flexors
    o Initiation of eccentric hip extensors (HS) (slow down limb in OKC) to control hip flexion
  2. Knee
    o Knee extension created by momentum
    o Knee flexors contract eccentrically at the end of MSw to control extension
  3. Ankle
    o Continued concentric contraction of dorsiflexors
26
Q

What critical event occurs at TSw?

A

Knee ext to neutral

27
Q

Describe what is happening at hip/knee/ankle muscle activation in sagittal plane at the TSw phase of gait?

A
  1. Hip
    o Concentric contraction of hip extensors
  2. Knee
    o Concentric contraction of knee extensors to insure full extension
    o (Peak hamstring eccentric contraction to decelerate thigh)
  3. Ankle
    o Continued concentric contraction of dorsiflexors
28
Q

At what phase does GMed peak?

A

Concentric contraction of hip extensors during LR

29
Q

At what phase do quads peak?

A

Eccentric contraction (shock absorption) of knee extensors during LR

30
Q

At what phase do Tib anterior peak?

A

Eccentric contraction (slow down) ankle dorsiflexion during LR

31
Q

At what phase do the gastroc/solesu peak?

A

Concentric contraction of ankle plantarflexors to prevent tibial collapse with heel rise during TSt

32
Q

At what phase does the adductor longus peak?

A

Concentric contraction of hip flexors during PSw

33
Q

At what phase does the iliacus peak?

A

Continued concentric contraction of hip flexors during ISw

34
Q

At what phase do the toe extensors peak?

A

Concentric contraction of tib anterior during ISw

35
Q

At what phase do the hamstrings peak?

A

eccentric contraction to decelerate thigh during TSw

36
Q

T/F Knee has no movement in frontal plane

A

True

37
Q

Muscle activation in frontal plane during LR for hip/ankle?

A
  1. Hip
     Hip abductors contracting eccentrically
     GMed & Adductor Magnus peak (stays active throughout entire stance face = eccentric to concentric)
  2. Ankle
     Inverters contracting eccentrically
38
Q

Muscle activation in frontal plane during MSt for hip/ankle?

A
  1. Hip
     Hip abductors contracting eccentrically then concentrically
  2. Ankle
     Inverters contracting eccentrically
39
Q

Muscle activation in frontal plane during TSt and PSw for hip/ankle?

A
  1. Hip
     Hip abductors contracting concentrically (level pelvis, turn back on to get ready for weight acceptance)
  2. Ankle
     Inverters contracting concentrically
40
Q

Muscle activation in frontal plane during ISw, MSw, and TSw for hip/ankle?

A
  1. Hip - Hip adductor contract concentrically (help advance leg)
  2. Ankle - Evertors contracting concentrically
41
Q

What are the key roles of the ankle dorsiflexors during gate?

A

Eccentric activation to control plantar flexion of the ankle at IC until foot flat

42
Q

What are the key roles of the ankle plantar flexors during gate?

A
  1. Eccentric contraction moving into MSt to control tibial advancement
  2. Concentric contraction at TSt assists with forward propulsion
43
Q

What are the key roles of the ankle invertors (tib posterior) during gate?

A
  1. Eccentrically contracts to control pronation until MSt

2. Concentrically contracts to supinate the foot for push-off in TSt/PSw

44
Q

What are the key roles of the ankle evertors during gate?

A

Also active as co-contraction to counter strong inversion effect occurring during LR/MSt

45
Q

What are the key roles of the knee extensors during gate?

A
  1. Eccentrically control knee flexion in LR (shock absorbers)
  2. Concentrically to extend the knee and support body in MSt
46
Q

What are the key roles of the knee flexors during gate?

A
  1. Decelerate knee extension in preparation for placement of the foot on the ground (eccentrically)
47
Q

What are the key roles of hip extensors during gait?

A
  1. Activated in TSw prior to IC to initiate hip extension and prepare LE for weight acceptance at the beginning of stance
48
Q

What are the key roles of hip flexors during gait?

A
  1. Advance lower extremity forward during ISw

2. Concentrically lift lower extremity to allow for toe clearance during swing

49
Q

What are the key roles of hip abductors during gait?

A
  1. Control the slight lowering of the contralateral pelvis on the side of the swing limb then provide pelvic stability in stance
50
Q

What are the key roles of hip adductors during gait?

A
  1. Assist with initiation of hip flexion after toe off
51
Q
Trendelenburg Gait:
Phase?
Plane?
Observation?
Causes?
Result?
A
  • Phase: LR-PSw
  • Plane: Frontal
  • Observation: Excessive downward drop of the contralateral pelvis during stance
  • Causes: GMed weakness (mild)
  • Result: functionally longer swing limb, decreased efficiency, possible decreased stance time
52
Q
Compensated Trendelenburg:
Phase?
Plane?
Observation?
Causes?
Result?
A
  • Phase: LR-PSw
  • Plane: Frontal
  • Observation: trunk lean toward over the stance limb, level pelvis
  • Causes: GMed weakness (moderate - severe)
  • Result: compensates by not allowing the contralateral pelvis to drop during stance by reducing demand on GMed
53
Q
Foot Slap:
Phase?
Plane?
Observation?
Causes?
Result?
A
  • Phase: IC-LR
  • Plane: Sagittal
  • Observation: PF torque goes unchecked by anterior tib
  • Causes: Tib Ant weakness (peroneal n. palsy, or peripheral neuropathy)
  • Result: Rapid PF after heel contact, can be audible. Usually can clear foot during swing
54
Q
Knee Extension Thrust:
Phase?
Plane?
Observation?
Causes?
Result?
A
  • Phase: IC
  • Plane: Sagittal
  • Observation: Knee snapping back into extension early in stance phase
  • Causes: Quad spasticity from UMN lesion
  • Result: Rapid and often excessive knee extension during LR, can occur w/cause knee hyperextension over time