10) Muscle Function During Gait

Question 1

Gait

Answer 1

• A manner or style of walking, running or any other form of repetitive bipedal human locomotion

Question 2

Step

Answer 2

• Distance covered from a given point on the foot to the same point on the other foot during one half of a gait cycle

Question 3

Stride

Answer 3

• Distance covered by a given point on the foot during one complete cycle of gait

Question 4

Cadence

Answer 4

• Number of steps per minute

Question 5

Phases of gait

Answer 5

• Stance (60%)

- Swing (40%)

Question 6

Periods of stance phase

Answer 6

• Contact (27%)
• Midstance (40%)
• Propulsion (33%)

Question 7

Double stance phasic gait

Answer 7

• ie. “Walking”

- Both feet on the ground at the same time

Question 8

Double float phasic gait

Answer 8

• ie. “Running”

- Both feet off the ground at the same time

Question 9

Shear vs. compression In lesion formation

Answer 9

• > 10 Newtons (~70 Lbs/inch)
  will cause tissue breakdown
• Shear increases the effect of compression (positive linear relationship)

Question 10

Combined vertical/horizontal forces on lower extremity

Answer 10

• Point of maximum compensation (PMC) at midstance

- Lower at contact, highest at midstance, lower at propulsion

Question 11

Ambulatory muscle sequencing

Answer 11

• Generally tend to fire in groups
• Demonstrate a “silent” period during swing phase
• Extensors are biphasic

Question 12

Tendency of muscles to fire in groups

Answer 12

• “Stairstep mobilization”
• Largest muscles tend toward dominancy
• No intrinsic activity during contact period

Question 13

Muscles demonstrates a “silent” period during swing phase

Answer 13

• Occurs between 80-90% of total gait cycle

- Ends one phase of biphasic extensors

Question 14

Extensors are biphasic

Answer 14

• Silent during swing phase

- Silent again during midstance period of stance phase

Question 15

Superficial posterior group firing

Answer 15

• Soleus before gastrocnemius

- Gastrocnemius longer than soleus

Question 16

Deep posterior muscle group firing

Answer 16

• Tibialis posterior longest firing muscle

- FHL & FDL begin @ ffl

Question 17

Peroneal muscle group firing

Answer 17

• Begin & and at ~ same time

Question 18

Extensor muscle group firing

Answer 18

• Biphasic except for Peroneus tertius
• Peroneus tertius with EDL
• Tibialis anterior comes closest to midstance

Question 19

Dorsal intrinsic muscle group firing

Answer 19

• EDB > EHB

Question 20

Plantar intrinsic muscle group firing

Answer 20

• Largest muscle is shortest firing (FDB)

- Longest firing muscle is FHB

Question 21

Muscle sequencing group names

Answer 21

• Superficial posterior
• Deep posterior
• Peroneal
• Extensor
• Dorsal intrinsic
• Plantar intrinsic

Question 22

Quadriceps muscle group firing

Answer 22

• Begins in last 1/3rd of swing phase
• Fire at heel strike, throughout contact period
• Ends in midstance

Question 23

Hamstrings muscle group firing

Answer 23

• Begins during last ½ of swing phase
• Spans contact period
• Inactive during midstance and propulsion

Question 24

Adductor muscle group firing

Answer 24

• Active during propulsive period

Question 25

Iliopsoas muscle group firing

Answer 25

• Begins during propulsive period

- Ends during swing phase

Question 26

Deep gluteal muscle group firing

Answer 26

• Begins with midstance period

- Ends in swing phase

Question 27

Superficial gluteal muscle group firing

Answer 27

• Begins late swing phase

- Ends at beginning of propulsive period

Question 28

Above the knee muscle sequencing group names

Answer 28

• Quadriceps
• Hamstrings
• Adductors
• Iliopsoas group
• Deep gluteal group
• Superficial gluteal group