Step-by-Step Assessment of Coordination

Why Coordination Matters

• Cooperation of agonist and antagonist muscles
• Maintenance of posture
• Servomechanisms controlling rate and range of movements

Step 1 — Observe First (Before Any Formal Testing)

• Note any tremor at rest or with posture
• Watch how they walk in, sit down, undress
• Look for dysmetria (over/undershooting), dysrhythmia (abnormal timing), or clumsiness

Step 2 — Upper Limb Coordination Tests

A. Rapid Alternating Movements (RAMs) — Tests for Dysdiadochokinesis

1. Ask the patient to make a fist, partially extend the index finger, and tap the index finger on the distal thumb as quickly as possible
2. Or: alternately tap the palm then dorsum of one hand on the opposite hand (pronation/supination)
3. Observe for:
   • Imprecision or variable amplitude/rhythm → cerebellar lesion
   • Slowness only (compared to other side) → pyramidal (corticospinal) lesion
   • Abnormal RAMs = dysdiadochokinesis or adiadochokinesis

B. Finger-Nose-Finger (FNF) Test — Tests for Dysmetria & Intention Tremor

1. Ask the patient to alternately touch their own nose and then the examiner's outstretched finger
2. Move your finger to a different position with each repetition to increase sensitivity
3. Hold your target finger at the limit of the patient's reach to maximise the arc
4. Look for:
   • Dysmetria (past-pointing, overshoot or undershoot)
   • Intention tremor (tremor that worsens as the finger approaches the target)
   • Decomposition of movement (movement broken into segments)

C. Precision Tap — Useful when Motor Weakness Is Present

1. Ask the patient to repeatedly tap the tip of the index finger on the crease of the thumb
2. In cerebellar disorders, the tip hits a different spot on the thumb each time
3. Useful when full FNF cannot be performed due to weakness

D. Rebound / Loss of Check Test

1. Ask the patient to hold both arms outstretched, then suddenly raise or lower them to a target level
2. Alternatively, apply downward pressure on the outstretched arms and suddenly release
3. Cerebellar lesions: limb overshoots (loss of check) rather than halting smoothly

Step 3 — Lower Limb Coordination Tests

A. Heel-Shin Test — Lower Limb Equivalent of FNF

1. Patient lies supine (important — removes gravity effect)
2. Ask them to place one heel on the opposite knee, then slide it down the shin to the ankle, and repeat
3. The movement should be in a straight line
4. Variations: tap the heel repeatedly on a spot just below the knee, or alternate the heel between the knee and the examiner's finger
5. Look for: wobbling, deviation off the shin, irregular rhythm

B. Foot Tapping

1. Ask the patient to rapidly tap the foot against the floor or the examiner's hand
2. Assess for irregular amplitude or rhythm (dysrhythmia)

Step 4 — Gait Assessment (Critical Component)

Step 5 — Romberg Test (Proprioception vs Cerebellar)

1. Ask the patient to stand with feet together, first with eyes open, then close the eyes
2. Positive Romberg (falls/sways with eyes closed) = sensory ataxia (proprioceptive loss — posterior column or peripheral nerve)
3. Cerebellar ataxia is present even with eyes open and does not significantly worsen with eye closure
4. In vestibular disease, patient tends to fall toward one side

Step 6 — Ocular Motor Coordination

Step 7 — Interpret the Pattern

Quick Bare-Minimum Screen

1. Observe the patient at rest and with spontaneous movement
2. Rapid alternating movements of hands and feet
3. Finger-to-nose test