Lower Limb Nerve Injuries and Gait

Question 1

If gravity causes flexion at a particular joint, then the extensor muscles that cross that joint function in an

Answer 1

Isometric fashion to prevent gravitational movement

Question 2

When analyzing muscle action in the lower limb, it is essential to be cognizant of whether the limb is

Answer 2

Weight bearing or not

Question 3

When weight bearing, the distal end of the limb is

Answer 3

Fixed

Question 4

When not weight bearing, the distal end of the limb is

Answer 4

Moveable

Question 5

During quiet standing, without sway, at the HIP, gravity tends to cause

Answer 5

Extension

Question 6

Gravity tends to cause extension at the hip during quiet standing. This is resisted by the

Answer 6

Illiofemoral ligament and ischiofemoral ligament

Question 7

During quiet standing, at the KNEE, gravity tends to cause

Answer 7

Extension

Question 8

The extension of the knee caused by gravity during quiet standing is resisted by the

Answer 8

Posterior joint capsule of the knee

Question 9

During quiet standing, at the ANKLE, gravity tends to cause

Answer 9

Dorsiflexion

Question 10

The dorsiflexion of the ankle caused by gravity during quiet standing is resisted by

Answer 10

Plantar flexors

Question 11

In an average adult male in anatomical position, the center of gravity is located immediately anterior to

Answer 11

S2

Question 12

Vector connecting the center of gravity to the center of the earth

-i.e. perpendicular to the ground

Answer 12

Line of gravity

Question 13

In order for an object to maintain stability, the line of gravity must pass within the

Answer 13

Supporting base

Question 14

Stability is increased by widening the

Answer 14

Supporting base

Question 15

In order to maintain stability, in a jointed structure, the line of gravity must pass through the

Answer 15

Axis of rotation of each joint

Question 16

At the hip, posterior displacement of the center of gravity increases

Answer 16

Extension torque

Question 17

This extension torque is resisted by

Answer 17

Hip flexors

Question 18

At the hip, anterior displacement of the center of gravity decreases

Answer 18

Extension torque

Question 19

Further anterior displacement of the center of gravity converts gravity to

Answer 19

Flexion torque

Question 20

Flexion torque at the hip is resisted by

Answer 20

Hip extensors (i.e. hamstrings)

Question 21

At the knee, posterior displacement of the center of gravity decreases

Answer 21

Extension torque

Question 22

Further posterior displacement of the center of gravity converts gravity at the knee to

Answer 22

Flexion torque at the knee

-resisted by knee extensors

Question 23

At the knee, anterior displacement of the center of gravity increases

Answer 23

Extension torque

-resisted by hamstrings

Question 24

At the ankle, what is the effect of posterior displacement of the center of gravity?

Answer 24

Dorsiflexion torque is decreased

Question 25

At the ankle, what is the effect of anterior displacement of the center of gravity?

Answer 25

Increased dorsiflexion torque

Question 26

What are the 5 stages of the gait cycle?

Answer 26

1. ) Heel strike 2. ) Foot flat 3. ) Midstance 4. ) Heel off 5. ) Toe off

Question 27

What are the effects of anterior sway at the 1. ) Hip 2. ) Knee 3. ) Ankle

Answer 27

1. ) Flexion 2. ) Extension 3. ) Dorsiflexion

Question 28

What are the effects of posterior sway at the 1. ) Hip 2. ) Knee 3. ) Ankle

Answer 28

1. ) Extension 2. ) Flexion 3. ) Platarflexion

Question 29

At heel strike, what is the tendency at the 1. ) Hip 2. ) Knee 3. ) Ankle

Answer 29

1. ) Flexion 2. ) Flexion 3. ) Plantarflexion

Question 30

At heel strike, the following are controlled by? 1. ) Flexion at hip 2. ) Flexion at knee 3. ) Plantarflexion at ankle

Answer 30

1. ) Gluteus maximus and hamstrings 2. ) Quadriceps femoris 3. ) Dorsiflexors

Question 31

At midstance, what is the tendency at the 1. ) Hip 2. ) Knee 3. ) Ankle

Answer 31

1. ) Adduction 2. ) Flexion 3. ) Dorsiflexion

Question 32

At midstance, the following are controlled by? 1. ) adduction at hip 2. ) Flexion at knee 3. ) Dorsiflexion at ankle

Answer 32

1. ) Gluteus medius and minimus 2. ) Quadriceps femoris 3. ) Gastrocnemius and soleus

Question 33

At heel off and toe off, there is a tendency for the hip to be

Answer 33

Extended

Question 34

The extension of the hip at heel off and toe off is resisted by the

Answer 34

Hip flexors

Question 35

The propulsive force during gait is provided by the

Answer 35

Plantarflexors

Question 36

This plantarflexion pushes the ground

Answer 36

Downward and backward

Question 37

The efficiency of gait is improved by positioning the limb so that at heel off and toe off, more of the vector pushes

Answer 37

The ground bckwards, and less pushing downwards

Question 38

The gluteus maximus is innervated by the

Answer 38

Inferior gluteal nerve (L5, S1, and S2)

Question 39

What happens if the gluteus maximus is paralyzed and no compensatory mechanism is activated?

Answer 39

Patient will fall over at heel strike

Question 40

To prevent this, the patient compensated by

Answer 40

Displacing mass of torso posteriorly at heel strike (gluteus maximus gait or lurch gait)

Question 41

The gluteus medius-minimus complex is innervated by the

Answer 41

Superior gluteal nerve (L4, L5, and L6)

Question 42

Active at the time of midstance to prevent gravitational adduction of the pelvis at the hip

Answer 42

Gluteus medius-minimus complex

Question 43

If the gluteus medius-minimus complex is paralyzed, the patient will compensate by

Answer 43

Displacing mass of upper torso laterally to the supported side at the time of midstance

Question 44

The gait resulting from gluteus medius-minimus paralysis is called

Answer 44

Tredelenburg gait

Question 45

The quadriceps femoris are innervated by the

Answer 45

Femoral nerve (L2, L3, and L4)

Question 46

Active throughout the stance phase to control gravitational flexion of the thigh at the knee

Answer 46

Quadriceps

Question 47

If the quadriceps were paralyzed, the patients knee would buckle in the stance phase. to compensate for this, the patient goes through the stance phase with

Answer 47

The knee completely extended and locked ("quadriceps gait")

Question 48

This converts gravity from a knee flexor into a

Answer 48

Knee extensor

Question 49

The anterior tibial muscles are innervated by the

Answer 49

Deep fibular nerve (L4, L5, and S1)

Question 50

Active during the swing phase to dorsiflex the foot and thus avoid having the toes hit the ground

Answer 50

Anterior tibial muscles

Question 51

Become very active at heel strike in order to gradually lower the foot to the foot flat position

Answer 51

Anterior tibial muscles

Question 52

If the anterior tibialis muscles are weak, we will see

Answer 52

"Foot slap" immediately after heel strike

Question 53

If the anterior tibialis muscles are paralyzed, the patient will enter the stance phase with a

Answer 53

Toe strike instead of heel strike

Question 54

To avoid having the toes hit the ground during the swing phase, the patient will

Answer 54

Increase flexion at the hip and knee, bringing foot higher above ground ("steppage gait)

Question 55

The fibularis (peroneus) longus and brevis are everters of the ankle and are innervated by the

Answer 55

Superficial fibular nerve (L5, S1, and S2)

Question 56

If these muscles are paralyzed in addition to the anterior tibialis muscles, then during the swing phase the foot will be

Answer 56

Inverted in addition to plantarflexed

Question 57

To avoid entering the stance phase in the inverted position, the patient will

Answer 57

Swing the lower limb laterally during swing, thus bringing plantar surface of the foot in contact with the ground at end of swing