16. Possible anatomical localisation of foot drop
Deep Peroneal Nerve
Common Peroneal Nerve
Sciatic Nerve
Lumbosacral Plexus
L5 root
17. Clinical approach to foot drop: motor exam
Deep
Peroneal
Nerve
Common
Peroneal
Nerve
Sciatic Nerve Lumbosacral
Plexus
L5 root
Weakness of
foot
dorsiflexion
Weakness of
foot eversion
Weakness of
foot inversion
Weakness of
knee flexion
Weakness of
glutei
18. Clinical approach to foot drop: sensory exam
Deep
Peroneal
Nerve
Common
Peroneal
Nerve
Sciatic
Nerve
Lumbosacra
Plexus
L5 root
Sensory loss
in web space
great toe
Sensory loss
in dorsum of
foot
Sensory loss
in lateral calf
Sensory loss
in lateral knee
Sensory loss
in sole foot
Sensory loss
in posterior
thigh
19. Clinical approach to foot drop: other sign
Deep
Peroneal
Nerve
Common
Peroneal
Nerve
Sciatic
Nerve
Lumbosacra
Plexus
L5 root
Tinel’s sign
at fibular
neck
Hip and
thigh pain
Back pain
Positive
straight-leg
raise test
20. NCS protocol for foot drop
Peroneal motor study - recording extensor digitorum brevis
If there is no focal slowing or conduction block at the fibular neck
perform a peroneal motor study - recording tibialis anterior
Tibial motor study- recording abductor hallucis brevis
Superficial peroneal sensory study
Sural sensory study
Tibial and peroneal F responses
21. Electromyographic Protocol for foot drop: Routine
At least two muscles innervated by the deep peroneal nerve (e.g., tibialis
anterior, extensor hallucis longus)
At least one muscle innervated by the superficial peroneal nerve (e.g.,
peroneus longus, peroneus brevis)
Tibialis posterior and at least one other tibial muscle (e.g., medial
gastrocnemius, soleus, flexor digitorum longus)
Short head of the biceps femoris
22. If the short head of the biceps femoris is abnormal
or
If any tibial-innervated muscle is abnormal
or
If nerve conduction studies demonstrate a non-localizing peroneal
neuropathy or abnormal tibial motor or sural responses
more extensive needle examination of other sciatic, gluteal, and
paraspinal muscles should be performed to identify the level of the lesion
Electromyographic Protocol for foot drop: special
23. Nerve Conduction Study Findings
Deep Peroneal
Nerve
Common
Peroneal Nerve
Sciatic Nerve
Lumbosacral
Plexus
L5
Low peroneal
CMAP (if axonal)
Low tibial CMAP
(if axonal)
Abnormal
peroneal SNAP (if
axonal)
Abnormal sural
SNAP (if axonal)
Abnormal H reflex
Conduction
slowing/block at
fibular neck (if
demyelinating)
26. Methods
Peroneal Motor Study
Recording Site: Extensor digitorum brevis (EDB) muscle
G1 placed over the muscle belly
G2 placed distally over the metatarsal–phalangeal joint of the little toe
Stimulation Sites
Ankle: Anterior ankle, slightly lateral to tibialis anterior tendon
Below fibular head: Lateral calf, one to two fingerbreadths inferior to fibular head
Lateal popliteal fossa (above fibular neck): Lateral knee, adjacent to external hamstring
tendons, at a distance of 10–12 cm from the below-fibular head site
27. Distal stimulation site over
the anterior ankle, slightly
lateral to the tibialis anterior
tendon
Proximal stimulation site
below the fibular head.
Proximal stimulation site in
the lateral popliteal fossa
above the fibular neck.
28. Peroneal Motor Study
Tibialis anterior (TA) muscle
G1 placed over the muscle belly
G2 placed distally over the anterior ankle
Distal stimulation site below the fibular head
Proximal stimulation site in the lateral popliteal fossa above the fibular
neck.
29.
30. Tibial Motor Study
Abductor hallucis brevis (AHB) muscle
G1 placed 1 cm proximal and 1 cm inferior to the navicular prominence
G2 placed over the metatarsal–phalangeal joint of the great toe
Stimulation Sites
Medial ankle: Slightly proximal and posterior to the medial malleolus
Popliteal fossa: Mid-posterior knee over the popliteal pulse
31.
32. Superficial Peroneal Sensory Study
G1 placed between the tibialis anterior tendon and lateral malleolus
G2 placed 3–4 cm distally
Stimulation Site
Lateral calf
33.
34. Sural Sensory Study
G1 placed posterior to the lateral malleolus
G2 placed 3–4 cm distally
Stimulation Site
Posterior–lateral calf
35.
36. Soleus H Reflex Study
G1 placed one to two fingerbreadths distal to where the soleus meets the
two bellies of the gastrocnemius
G2 placed over the Achilles tendon
Stimulation Site
Popliteal fossa: Mid-posterior knee over the popliteal pulse
39. Extensor Digitorum Brevis (EDB)
needle insertion:
• tangentially into the dorsum of the
foot two to three fingerbreadths distal
to the lateral malleolus.
• The muscle can often be easily felt by
having the patient extend all theirs toes
Activation
Have the patient extend the toes
40. Extensor Hallucis Longus (EHL)
Needle Insertion
• three to four fingerbreadths above
the ankle, just lateral to the tibialis
anterior tendon
Activation
• Have the patient extend the great toe
41. Tibialis Anterior (TA)
Needle Insertion
• just lateral to the tibial crest, two
thirds the distance up from the ankle
toward the knee
Activation
• Have the patient dorsiflex the ankle
42. Peroneus Longus (PL)
Needle Insertion
• lateral calf, three to four
fingerbreadths distal to the fibular
head
Activation
• Have the patient evert the ankle
44. Tibialis Posterior (TP)
Needle Insertion
medial to the tibia, slightly distal to the
mid-point between the ankle and knee,
deep to the flexor digitorum longus
Activation
Have the patient invert the ankle
45. Biceps Femoris–Short Head (BF–SH)
Needle Insertion
three to four fingerbreadths proximal to
the lateral knee, medial to the tendon to
the long head of the biceps femoris
Activation
Have the patient flex the knee
46. Gluteus Maximus (GMAX)
Needle Insertion
With the patient on their side, insert
the needle into the upper outer
quadrant of the buttock.
Activation
Have the patient extend the thigh
with the knee straight
47. Gluteus Medius (GMED)
Needle Insertion
With the patient lying on his or
her side and the side to be
studied placed upward, insert
the needle into the lateral thigh
two to three fingerbreadths
distal to the iliac crest
Activation
Have the patient abduct the
thigh
48. Lumbosacral paraspinal
Needle Insertion
two fingerbreadths from the midline spine
with the needle directed slightly medially.
To ensure that the needle is in the deeper
layer of muscles, it should be advanced to just
touch the lamina and then pulled back slightly
Activation
Have the patient extend the hip with the leg
straight