Nerves of the Lower Limbs Flashcards
1
Q
Which nerve roots are responsible for the following movements at the hip joint:
- Medial internal rotation
- Lateral external rotation
- Abduction
- Adduction
- Extension
- Flexion
A
- Medial internal rotation: L1, L2, L3
- Lateral external rotation: L1 and L5
- Abduction: S1 and L5
- Adduction: L1, L2, L3, L4
- Extension: L4 and L5
- Flexion: L2 and L3
2
Q
Which nerve roots are responsible for the following movements at the subtalar joint:
- Eversion
- Inversion
A
- Eversion: L5 and S1
- Inversion: L4 and L5
3
Q
Which nerve roots are responsible for the following movements at the metatarsophalangeal joint:
- Dorsiflexion
- Plantar flexion
A
- Dorsiflexion: L5 and S1
- Plantar flexion: S1 and S2
4
Q
Which nerve roots are responsible for the following movements at the knee joint:
- Extension
- Flexion
A
- Extension: L3 and L4
- Flexion: L5 and S1
5
Q
Which nerve roots are responsible for the following movements at the ankle joint:
- Dorsiflexion
- Plantar flexion
A
- Dorsiflexion: L4 and L5
- Plantar flexion: S1 and S2
6
Q
How many gluteal nerves are there ? What is their names ?
A
Two
Superficial gluteal nerve and Inferior gluteal nerve
7
Q
Describe the location and path of the superficial gluteal nerve relative to surrounding structures (including any possible change of name/divisions).
A
- Exits pelvis through suprapiriform space
- Runs laterally between the gluteus medius and minimus
- Splits into a superior branch (gluteus medius) and an inferior branch (gluteus minimus and tensor fasciae latae).
8
Q
What nerve root does the superficial gluteal nerve originate from ? the inferior gluteal nerve ?
A
Superficial gluteal nerve: L4-S1
Inferior gluteal nerve: L5-S2
9
Q
Describe the location and path of the inferior gluteal nerve relative to surrounding structures (including any possible change of name/divisions).
A
- Exits pelvis through infrapiriform space
- Runs deep to gluteus maximus
10
Q
What structure(s) does the gluteal nerve innervate ?
A
Inferior gluteal nerve innervates gluteus maximus
11
Q
When standing on one leg, which muscles are involve in keeping the pelvis level ?
A
Ipsilateral gluteus medius and minimus
12
Q
What are possible clinical findings following gluteal nerve injury ?
A
- Abduction of the thigh is affected
- Pelvis drops at the unaffected side
- Positive Trendelenburg test: Patients compensate for this by producing a waddling gait by raising the pelvis to allow clearance of the foot moving forward. - Medial rotation of the thigh is affected
13
Q
What are the nerve roots of the sciatic nerve ?
A
L4-S3
14
Q
Describe the location and path of the sciatic nerve relative to surrounding structures (including any possible change of name/divisions).
A
- Exits pelvis through infrapiriform space
- Runs deep to gluteus maximus, midway between the ischial tuberosity and the greater trochanter
- In 12% of the population, branches into the tibial and common fibular nerves upon exit from the pelvis
15
Q
Where should intragluteal injections be performed ?
A
In the superolateral quadrant of the buttock
16
Q
Which structures does the sciatic nerve provide sensory innervation to ? motor innervation ?
A
SENSORY
- Hip joint
MOTOR (Muscles in the posterior compartment of the thigh)
- Short head of biceps from common fibular division
- Rest of the hamstrings from tibial division
17
Q
What are possible causes of sciatic nerve injury ?
A
- Compression of the nerve by the muscle (including from muscle spasms) (More common in athletes and women)
- Direct injury/trauma to the nerve itself
18
Q
What are possible clinical findings following sciatic nerve injury ?
A
- Loss of extension of the hip
- Weakness in flexion of the leg
19
Q
What are the nerve roots of the common fibular nerve ?
A
L4-S2
20
Q
Describe the location and path of the common fibular nerve relative to surrounding structures (including any possible change of name/divisions).
A
- Originates at apex of popliteal fossa (as a continuation of sciatic nerve)
- Runs inferiorly and laterally following the medial border of the biceps
- Passes over the lateral head of the gastrocnemius
- Gives off lateral sural cutaneous branch (sensory)
- Winds around the neck of the fibula
21
Q
What are some possible causes of common fibular nerve injury ?
A
- Fibular (esp. neck) fracture
- Direct trauma
- Dislocation of the knee join
22
Q
What are possible clinical findings following common fibular nerve injury ?
A
- Signs and symptoms of deep fibular nerve injury
- Signs and symptoms of superficial fibular nerve injury
- Possible paresthesia in lateral aspect of knee, anterolateral aspect of leg (depending on level)
23
Q
Which structures does the common fibular nerve provide sensory innervation to ? motor innervation ?
A
SENSORY
- Skin over upper lateral and lower posterolateral leg directly.
- (via branches) Skin of the anterolateral leg,
- (via branches) Dorsum of the foot
MOTOR
- Short head of the biceps femoris directly.
- (via branches) muscles in lateral and anterior compartments of leg
24
Q
What are the nerve roots of the deep fibular nerve ?
A
L4-L5
25
Describe the location and path of the deep fibular nerve relative to surrounding structures (including any possible change of name/divisions).
- Arises between fibularis longus and neck of fibula
- Passes between tibialis anterior and extensor digitorum longus, descending down the interosseous membrane, accompanied by anterior tibial artery
- Enters the dorsum of the foot passing under the extensor retinaculum
- Gives rise to DORSAL DIGITAL NERVE to toes 1-2
26
Which structures does the deep fibular nerve provide sensory innervation to ? motor innervation ?
SENSORY
- Ankle joint
- Web space between the 1st and 2nd toes
MOTOR (muscles in the anterior compartment of the leg)
- Tibialis anterior
- Extensor hallucis longus
- Extensor digitorum longus
- Fibularis tertius
- Extensor digitorum brevis - Extensor hallucis brevis
27
What are some possible causes of deep fibular nerve injury ?
- Tight fitting shoes (e.g. ski-boot syndrome)
| - Compartment syndrome (nerve entrapment, because "pressure within the muscles builds")
28
What are possible clinical findings following deep fibular nerve injury ?
1. Paresthesia/anesthesia between the 1st and 2nd toes
2. Weakness in/Loss of function of muscles in anterior
compartment of the leg
If loss of extension of ankle --> Foot-drop+inverted --> Slap gait/Steppage gait
3. Pain in the anterior compartment of the leg
29
What are the nerve roots of the superficial fibular nerve ?
L5-S2
30
Which of anterior, posterior lateral compartment of the leg is deep fibular nerve territory ? superficial nerve territory ? tibial nerve territory ?
Anterior compartment is deep fibular nerve territory
Lateral compartment is superficial fibular nerve territory
Posterior compartment is tibial nerve territory
31
Describe the location and path of the superficial fibular nerve relative to surrounding structures (including any possible change of name/divisions).
- Arises between fibularis longus and neck of fibula
- Descends in lateral compartment of the leg
- At distal 1/3 of leg, emerges from the deep fascia
- Gives rise to CUTANEOUS BRANCHES and DORSAL DIGITAL NERVES to 2nd-5th toes along its course.
32
Which structures does the superficial fibular nerve provide sensory innervation to ? motor innervation ?
SENSORY
- Ankle joint
- Skin on anterior distal leg
- Skin on dorsum of foot
MOTOR (muscles in the lateral compartment of the thigh)
- Fibularis longus
- Fibularis brevis
33
What are some possible causes of superficial fibular nerve injury ?
- Chronic ankle sprains --> Stretching of the nerve
| - Direct injury
34
What are possible clinical findings following superficial fibular nerve injury ?
1. Paresthesia/anaesthesia along antero-lateral side of leg and dorsum of ankle and foot.
2. Loss of function of muscles in lateral compartment of the leg --> Loss of eversion
35
What are the nerve roots of the tibial nerve ?
L4-S3
36
Describe the location and path of the tibial nerve relative to surrounding structures (including any possible change of name/divisions).
- Arises from the SCIATIC NERVE at the apex of the popliteal fossa
- Postero-lateral to the popliteal vessels
- Gives off MEDIAL SURAL CUTANEOUS branch (sensory)
- Leave poplitea on popliteus muscle
- Passes under the tendinous arch of soleus and descends between superficial and deep flexors towards medial malleolus
- Passes into the sole behind medial malleolus, deep to the flexor retinaculum
- Divides into the MEDIAL AND LATERAL PLANTAR NERVES
37
Which structures does the tibial nerve provide sensory innervation to ? motor innervation ?
SENSORY
- Ankle joint
- Skin of the heel
MOTOR (muscles in the superficial and deep posterior compartments of the leg)
- Plantaris
- Popliteus
- Gastrocnemius
- Soleus
- Tibialis posterior
- Flexor hallucis longus
- Flexor digitorum longus
38
Which structures does the medial plantar nerve provide sensory innervation to ? motor innervation ?
SENSORY
- Anterior two-thirds of the sole
- Adjacent surfaces of the medial 3.5 toes
MOTOR
- Abductor hallucis
- Flexor digitorum brevis
- Flexor hallucis brevis
- Lumbrical 1
39
Which structures does the lateral plantar nerve provide sensory innervation to ? motor innervation ?
SENSORY
- Skin on the lateral side of the anterior two-thirds of the sole
- Adjacent plantar surfaces of the lateral 1.5 digits
MOTOR
-All plantar muscles other than those supplied by medial plantar nerve
40
What nerves do the lateral and medial plantar nerves give rise to ?
Plantar digital nerves
41
Why is injury to the tibial nerve rare ?
Because of its deep position
42
What are possible clinical findings following tibial nerve injury ?
1. Loss of ankle and digit plantarflexion
| 2. Loss of sensation to the sole
43
Describe the location and path of the sural nerve relative to surrounding structures (including any possible change of name/divisions).
- Formed by lateral cutaneous sural branch from the common fibular nerve and medial cutaneous sural branch from the tibial nerve
44
What is the clinical significance of the sural nerve ?
May be used as nerve graft
45
Which structures does the sural nerve provide sensory innervation to ? motor innervation to ?
PURELY SENSORY!
- Skin on the lower posterolateral surface of the leg
- Skin on lateral side of the foot and little toe
46
What are the nerve roots of the femoral nerve ?
L2-L4
47
Describe the location and path of the femoral nerve relative to surrounding structures (including any possible change of name/divisions).
- Travels anteriorly- inferiorly between iliacus and psoas major towards retro-inguinal space
- Passes through muscular compartment with iliopsoas and enters the thigh
- Gives off MUSCULAR, ANTERIOR CUTANEOUS FEMORAL and SAPHENOUS branches
48
Which structures does the femoral nerve provide sensory innervation to ? motor innervation ?
```
SENSORY
- Hip joint
- Knee joint
- Skin on the anterior surface of the
thigh by anterior cutaneous femoral branch
```
MOTOR (muscles in the anterior compartment of the thigh)
- Quadriceps femoris
- Sartorius
- Pectineus
- Iliacus
49
What are the nerve roots of the saphenous nerve ?
L3-L4
50
Describe the location and path of the saphenous nerve relative to surrounding structures (including any possible change of name/divisions).
- Enters the adductor canal with femoral artery
- Pierces lamina vastoadductoria and becomes superficial between the sartorius and gracilis
- Accompanies the greater saphenous vein in the leg
51
Which structures does the saphenous nerve provide sensory innervation to ? motor innervation ?
SENSORY
- Skin on the medial surface of the knee
- Anteromedial surface of leg
- Medial malleolus
52
What nerve may be at risk in venous access or varicose vein surgery ?
Saphenous nerve
53
What are the nerve roots of the obturator nerve ?
L2-L4
54
Describe the location and path of the obturator nerve relative to surrounding structures (including any possible change of name/divisions).
- Travels anteriorly on lateral pelvic wall towards obturator canal
- Passes through obturator canal and enters the medial aspect of the thigh
55
Which structures does the obturator nerve provide sensory innervation to ? motor innervation ?
SENSORY
- Hip joint
- Knee joint
- Upper half of medial thigh
MOTOR (muscles in the medial compartment of the thigh)
- Adductor magnus
- Adductor longus
- Adductor brevis
- Gracilis
- Obturator externus
56
What are some possible causes of obturator nerve injury ?
- Patient positioning during total hip replacement
- Pelvic trauma
- Very strenuous exercise (excessively tight muscles)
57
What are possible clinical findings following obturator nerve injury ?
- Paraesthesia or pain in the medial thigh, groin or pubic bone
- Weakness in/loss of adduction of the thigh
