Routine for examination of lower limbs:
Inspect (walking aids, splints, wasting)
Tone
Power (and test inversion and eversion)
Feel fibula head and observe for scar in this area and around the knee
Reflexes
Sensation (and test sensation on sole, lateral leg and foot dorsum and webspace between 1st and 2nd toes)
Coordination
Gait and Rhomberg’s test
Look at shoe soles (worn anteriorly and laterally)
Look at hands (diabetic fingerprick marks, vasculitic signs, rheumatoid arthritis)
Examine the back for scars
Present to the examiner:
This patient has a right sided foot drop as evidenced by:
Wasting of the lateral lower leg. There were (no) fasciculations. Comment on the tone.
Weak ankle dorsiflexion and eversion. Comment on whether inversion was normal or not and whether plantarflexion was normal or not.
Comment on whether the ankle reflex was intact or not
Describe the distribution of the sensory loss eg. lateral lower leg, foot dorsum, webspace between 1st and 2nd toes, sole
There was a high stepping gait. The patient could walk on his/her toes but not their heel. There was a walking aid/splint by the bedside. Shoe soles were worn anteriorly and laterally.
I could find no scars in the fibula area or the back
I examined the hands for clues of the causes of neuropathy
Causes of Foot Drop:
*Think anterior horn cell—nerve root—plexus—peripheral nerve—NMJ—muscle*
- Muscle (weak anterior tibialis): any cause of myopathy
- Nerve (common peroneal nerve palsy): mono/polyneuropathy eg. trauma to fibular head, surgery on leg, compression of fibula neck by cast/tourniquet/leg crossing/bandaging, mononeuritis multiplex of any cause
- Sciatic nerve palsy eg. trauma, IM injection
- Lumbosacral plexopathy eg. trauma, tumour
- L5 root lesion eg. prolapsed disc
- Anterior horn cell eg. motor neuron disease (NB: no sensory deficit)
- Spinal cord or brain lesion (stroke, space-occupying lesion, demyelination)- causing bilateral foot drop
Common peroneal nerve palsy: inversion is intact, ankle reflex is intact. Deep branch only: preserved eversion and sensory loss only in webspace between 1st and 2nd toes and not lateral lower leg or foot dorsum
Sciatic nerve lesion: weak knee flexion, lose ankle jerk, lose plantarflexion of foot as well as dorsiflexion, eversion, inversion, there is more widespread sensory loss
L5 lesion: lose inversion as well as eversion and dorsiflexion, lose sensation on sole of foot as well as anterolateral shin and foot dorsum, cannot straight leg raise, ankle jerk preserved
Investigations:
Bloods to screen for causes of neuropathy/mononeuritis multiplex eg. autoimmune, infectious, inflammatory, endocrine causes eg. diabetes
Urine dipstick for blood and protein
EMG and Nerve conduction studies
Xray fibula
MRI spine and sacrum
Management:
Conservative: splint/calliper, avoid squatting/leg crossing, physio, OT, DVLA considerations
Medical: analgesia, treat the underlying cause
Surgical: repair fracture/severed nerve
Written by Dr Sarah Kennedy
Resources used to write this document are listed in the references section of this webpage