Lower Limb Examination

Original article by Ruichong Ma | Last updated on 10/2/2016
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The key aim is to identify the anatomical site of the lesion: central (UMN - brain and spinal cord)versus peripheral (LMN - nerve roots and peripheral nerves).
NB – neurological examination of the limbs tests both the peripheral and central nervous systems.
The pattern of signs is usually more important than a single sign (e.g. glove-and-stocking sensory loss, left-sided UMN weakness etc.)
Examination of the cranial nerves should be performed with neurological examination of the limbs as part of a complete neurological examination.
 
Mnemonic:
To Postpone Reflexes Constitutes Stupidity
Tone, Power, Reflexes, Co-ordination, Sensation
To start - WIPE
Wash your hands
Introduce yourself to the patient
Permission - to examine the patient
Position - start with the patient sitting
Pain - check that the patient has no pain
Exposure - both upper limbs from shoulders to fingers
End of the bed
Surroundings
Monitoring: ECG (autonomic problems)
Treatments: O2, IV infusions (IV Ig)
Paraphernalia: wheelchair, mobility aids
Patient
Asymmetry, deformity or abnormal posture
Resting tremor
Wasting (proximally quadriceps; distally tibialis anterior)
Fasciculation (quadriceps; gastrocnemius)
Ask patient to walk away, turn around and walk back
•Delayed Initiation (Parkinson’s)
•Loss of arm swing (early sign in Parkinson’s)
•Festination (Parkinson’s)
•Scissoring (due to spasticity i.e. UMN lesion)
•Waddling (proximal muscle weakness)
•Foot drop (LMN lesion, specifically L4, L5 or common peroneal nerve)
•Heel to toe walking (ataxia)
•Romberg’s (proprioceptive loss)
Tone
Ask patient to relax
• “Pastry-roll” each leg to test ankle tone
• Lift knee suddenly - heel lifts off bed if tone increased
• Ankle clonus (>5 beats; test with knee bent)
Power
MRC scale of 0-5
Start proximally
When describing weakness, think in terms of:
Proximal versus distal
Unilateral versus bilateral
Movement
Muscle
Root
Nerve
Hip Flex
Iliopsoas
L1, L2
Femoral
Hip Ext
Gluteus maximus
L5, S1
Inf gluteal
Knee Ext
Quadriceps
L3, L4
Femoral
Knee Flex
Hamstrings
S1
Sciatic
Ankle dorsiflexion
Tibialis anterior
L4
Deep peroneal
Ankle plantarflexion
Gastrocnemius
S1, S2
Tibial
Big toe Ext
Ext hallucis longus
L5
Deep peroneal
Reflexes
Hold tendon hammer at the end, let it fall in a fluid movement.
If unable to elicit a reflex try with reinforcement - Jendrassik manoeuvre (patient locks their fingers together and pulls)
Look at the muscle belly when testing a reflex
Reflex
Root
Nerve
Knee
L3, L4
Femoral
Ankle
S1, S2
Sciatic
Plantar
Extensor (UMN lesion), Flexor, absent
Coordination
Tests cerebellar function - omit if upper limbs are weak.
Heel shin test (look for dysmetria and intention tremor)
Tap feet on floor or end of bed (dysdiadochokinesis)
Sensation
Test distally to proximally. Look for “glove” or dermatomal loss.
Light touch with fingers (tests spinothalamic pathway)
• Get the patient to close their eyes and look for extinction
Test rapidly, running up the arms then work down the arms specifically testing dermatomes as per the diagram
If deficit detected, consider refining deficit by using wisp of cotton wool (dorsal columns) as well as pin prick and testing temperature sensation (spinothalamic columns)
Proprioception or vibration sense (tests dorsal columns)
Closure
• Thank the patient
• Make sure the patient is comfortable and clothed
• Wash your hands
• Put your findings together - is the lesion central or peripheral?
To Finish
• Examine the upper limbs and cranial nerves
Only if relevant to findings so far:
• Other cerebellar signs: DANISH
• Visual fields (UMN weakness suspected stroke)
• Speech examination (UMN weakness suspected stroke)
• FVC (Guillain Barré)
 
MRC Power Scale
No movement
1
Flicker of Movement
2
Movement with gravity but not against
3
Movement against gravity but not resistance
4
Reduced power against resistance
5
Normal power against resistance
 
Pattern of findings in UMN vs LMN lesion
 
 
UMN
LMN
Inspection
Spastic posture
Wasting after 2 - 3 weeks
Fasciculation
Tone
Increased +/- clonus
Decreased
Power
Weakness (in a pyramidal pattern if cortical UMN lesion)
Weakness in distribution of nerve/root/muscle group
Reflexes
Hyperreflexic, extensor plantars
Hyporeflexic, flexor plantars

 

Dermatomes