Why the Neurological Examination Feels Difficult — and How to Fix That
The neurological examination is one of the most feared OSCE stations. Students lose marks not because they lack knowledge, but because they rush, skip steps, or forget to interpret what they find. The secret is a rigid sequence. Once your hands are moving through a practised routine, your brain is free to interpret findings and formulate a diagnosis.
There are two neurological examinations you must be able to perform: upper limb and lower limb. Both follow the same five-domain structure: Inspection → Tone → Power → Reflexes → Sensation, followed by coordination. Learn this sequence in order and never deviate.
💡 Tip
OSCE opening line: "I'd like to examine the motor and sensory function of your upper/lower limbs. Is that okay? I'll let you know if anything is uncomfortable." Wash hands, expose appropriately (arms to shoulder, legs to upper thigh if lower limb), and position the patient sitting upright.
The Five Domains: What You're Assessing and Why
| Domain | What it tests | What abnormality tells you |
|---|---|---|
| Inspection | Wasting, fasciculations, asymmetry, deformity | LMN lesion (wasting), UMN (pyramidal posture) |
| Tone | Resistance to passive movement | UMN = spasticity/clasp-knife; LMN = flaccidity; cerebellar = normal/hypotonic |
| Power | MRC grade 0–5 against resistance | Level and laterality of lesion |
| Reflexes | Deep tendon reflex arc integrity | UMN = brisk/clonus; LMN = absent/reduced |
| Sensation | Light touch, pain, proprioception, vibration | Sensory level, peripheral neuropathy pattern, dissociated sensory loss |
Upper Limb Neurological Examination
Inspection
Stand back and look. Look for muscle wasting (thenar, hypothenar, interossei), fasciculations (flickering under the skin at rest — LMN sign), tremor (resting = Parkinson's; intention = cerebellar), pronator drift (arms outstretched, eyes closed — drifts and pronates in UMN lesion), and posture (flexed arm/extended leg = pyramidal posture of UMN).
Tone
Support the patient's forearm and passively flex and extend the elbow, then supinate and pronate the wrist. Feel for:
- Spasticity (velocity-dependent resistance, clasp-knife release) — UMN
- Rigidity (lead pipe or cogwheeling at wrist) — extrapyramidal (Parkinson's)
- Flaccidity (no resistance) — LMN or cerebellar
💎 Clinical Pearl
Cogwheeling vs lead pipe: Cogwheel rigidity is lead pipe rigidity plus superimposed tremor. Both are extrapyramidal. Spasticity (velocity-dependent, clasp-knife) is a UMN sign.
Power
Test in the following order. Grade each using MRC 0–5:
| Movement | Nerve root | How to test |
|---|---|---|
| Shoulder abduction | C5 | Push down on abducted arm |
| Elbow flexion | C5/C6 | "Bend your arm, don't let me straighten it" |
| Elbow extension | C7 | "Push me away" |
| Wrist extension | C7 | Push down on dorsiflexed wrist |
| Finger extension | C7 | Push down on extended fingers |
| Finger abduction | T1 | "Spread fingers, don't let me squeeze them" |
| Thumb abduction | T1 | "Point thumb to ceiling, don't let me push it down" |
🧠 Mnemonic
MRC Power Scale — "No Movement, Flicker, Gravity Gone, Against Gravity, Against Resistance, Normal"
- 0 — No contraction
- 1 — Flicker of contraction only
- 2 — Movement with gravity eliminated
- 3 — Movement against gravity but not resistance
- 4 — Movement against some resistance (4−/4/4+)
- 5 — Full power
Reflexes
Use a tendon hammer with a swinging arc from the wrist. Grade as absent (0), reduced (+), normal (++), brisk (+++), very brisk with clonus (++++).
| Reflex | Root | Technique |
|---|---|---|
| Biceps | C5/C6 | Thumb on tendon, tap thumb |
| Supinator (brachioradialis) | C5/C6 | Tap radius 5 cm above wrist |
| Triceps | C7 | Tap triceps tendon directly |
If reflexes absent, reinforce — ask the patient to clench teeth or interlock fingers and pull just before striking.
Sensation
Test light touch first (cotton wool), then sharp/pain (neurotip), then proprioception (finger joint position — hold sides of finger, not top and bottom to avoid pressure cues), then vibration (128 Hz tuning fork on bony prominence). Compare left to right and proximal to distal.
Coordination
- Finger-nose test: Ask the patient to touch their nose then your finger repeatedly. Look for intention tremor (worsens as finger approaches target) and past-pointing — both cerebellar signs.
- Dysdiadochokinesia: "Tap the back of your hand alternately with palm and back of your other hand as fast as you can." Slow, clumsy, irregular tapping = cerebellar.
Lower Limb Neurological Examination
Follow the same five domains. Key differences:
Tone: Roll the leg at the hip passively. Lift the knee briskly off the bed — if the foot drags on the bed, tone is normal; if it flies up, tone is increased (UMN spasticity). Test for ankle clonus: dorsiflex the foot sharply and hold — sustained rhythmic beats = UMN lesion.
Power: Test hip flexion (L2/L3), knee extension (L3/L4), knee flexion (L5/S1), ankle dorsiflexion (L4/L5), ankle plantarflexion (S1/S2), and great toe extension (L5 — extensor hallucis longus).
Reflexes:
| Reflex | Root | Technique |
|---|---|---|
| Knee jerk | L3/L4 | Tap patellar tendon with knee supported at ~30° |
| Ankle jerk | S1/S2 | Dorsiflex foot, tap Achilles tendon |
| Plantar | L5/S1 | Stroke lateral sole with orange stick — Babinski sign (upgoing) = UMN |
⚠️ Red Flag
The Babinski sign: Normal response is downgoing (flexor) plantar — toes curl downward. An upgoing great toe (extensor plantar / Babinski positive) is a UMN sign and is always abnormal in adults. Make sure you stroke the lateral border of the sole smoothly — excessive tickling causes withdrawal not a true Babinski.
Coordination: Heel-shin test — ask the patient to run their heel smoothly down their shin from knee to ankle. Ataxic, wavering movement = cerebellar.
Gait: Always offer to test gait. Ask the patient to walk normally, walk heel-to-toe (tandem gait — ataxia), then walk on heels (L4/L5 foot drop) and tiptoes (S1 plantarflexion weakness).
UMN vs LMN: The Most Important Table in Neurology
| Feature | Upper Motor Neuron (UMN) | Lower Motor Neuron (LMN) |
|---|---|---|
| Location of lesion | Brain / spinal cord | Anterior horn cell, nerve root, peripheral nerve, NMJ, muscle |
| Tone | Increased (spastic) | Decreased (flaccid) |
| Power | Reduced (pyramidal distribution) | Reduced |
| Reflexes | Brisk ± clonus | Reduced or absent |
| Plantar | Upgoing (Babinski +) | Downgoing |
| Wasting | No (or disuse atrophy) | Yes |
| Fasciculations | No | Yes |
| Examples | Stroke, MS, cord compression | MND (AHC), disc prolapse, Guillain-Barré, CMT |
🧠 Mnemonic
UMN = "Upper = Up" — upgoing plantars, upper tone (spasticity), upper reflexes (brisk). Everything is exaggerated because the inhibitory control from above is lost.
LMN = "Lower = Lost" — lost tone (flaccid), lost reflexes, lost bulk (wasting), lost fasciculations eventually.
Dermatomes Worth Knowing for OSCEs
| Level | Landmark |
|---|---|
| C5 | Lateral upper arm (regimental badge area) |
| C6 | Thumb and index finger |
| C7 | Middle finger |
| C8 | Little finger and medial forearm |
| T1 | Medial upper arm |
| T4 | Nipple line |
| T10 | Umbilicus |
| L3 | Medial thigh |
| L4 | Medial lower leg and medial malleolus |
| L5 | Dorsum of foot and great toe |
| S1 | Lateral foot and sole |
How to Present Your Findings
"On examination of the upper limbs, there was no wasting or fasciculations at rest. Tone was increased in the right arm with a clasp-knife quality. Power was 4/5 throughout the right upper limb in a pyramidal distribution. Reflexes were brisk on the right, 2+ on the left, and the right plantar was upgoing. Sensation was intact to light touch, pin prick, and proprioception bilaterally. Coordination was intact. These findings are consistent with an upper motor neuron lesion affecting the right corticospinal tract. The most likely diagnosis, given this pattern, would be a right-sided cerebral lesion, most likely a stroke, and I would like to proceed with cranial nerve examination, assessment of the lower limbs, and arrange urgent neuroimaging."
Common Examiner Follow-Up Questions
"What is the difference between spasticity and rigidity?"
"Spasticity is a velocity-dependent increase in tone — resistance increases with the speed of passive movement and there may be a clasp-knife release. It is a UMN sign, caused by damage to the corticospinal tract. Rigidity is not velocity-dependent — resistance is constant throughout the range of movement, either as lead pipe rigidity or cogwheel rigidity when tremor is superimposed. Rigidity is an extrapyramidal sign seen in Parkinson's disease."
"What does a positive Babinski sign indicate?"
"A positive Babinski sign — upgoing great toe on stroking the lateral sole — indicates damage to the corticospinal (pyramidal) tract. It is normal in infants under 12–18 months when myelination is incomplete, but in adults it always represents an UMN lesion, such as stroke, spinal cord compression, or MS."
"A patient has foot drop. What nerve is likely affected and how would you differentiate L4/L5 root from common peroneal nerve?"
"Foot drop results from weakness of ankle dorsiflexion. The most common causes are common peroneal nerve palsy at the fibular neck — for example from prolonged squatting or plaster casts — or L4/L5 root compression from a disc prolapse. To differentiate: common peroneal palsy affects dorsiflexion and eversion but spares inversion (tibial nerve). L4/L5 root compression may also affect knee flexion (L5 via sciatic), hip abduction, and cause low back pain. Reflexes are typically preserved in common peroneal palsy but the ankle jerk may be reduced in L5 root lesions."