Upper vs Lower Motor Neuron Lesions

Muscle Tone

 * flexion/extension, pronation/supination of joint through its ROM

Hypotonia

 * LMN lesions, spinal shock, cerebellar lesions-flaccidity

Hypertonia

 * Spasticity - UMN lesion. Pyramidal tract involved
 * limb moves, then catches, and then goes past catch (clasp-knife)
 * test by rapidly supinating forearm
 * Rigidity
 * UMN lesions, extrapyrimidal tract lesion
 * increased tone throughout ROM (cog-wheeling, lead-pipe)
 * circumducting the wrist

Power

 * UMN
 * flexors > extensors in upper limbs
 * extensors > flexors in lower limbs
 * LMN
 * reduced power in specific motor neuron distribution
 * deltoids - arm abduction - C5 C6 (axillary)
 * biceps - elbow flexion - C5 C6 (musculocutaneous)
 * triceps - elbow extension - C6 C7 C8 (radial)
 * thumb flexion - C6 C7 (median)
 * wrist extensors - C7 C8 (radial)
 * interossei of hand - finger abduction/adduction - C8 T1 (ulnar)
 * hip flexion - L1 L2 L3 (femoral)
 * hip adduction - L2 L3 L4 (obturator)
 * hip abduction - L4 L5 S1 (superior gluteal)
 * knee extension - L2 L3 L4 (femoral)
 * knee flexion - L5 S1 S2 (sciatic)
 * ankle dorsiflexion - L4 L5 (deep peroneal)
 * ankle plantar flexion - S1 S2 (tibial)
 * foot inversion - L4 L5 (posterior tibial)
 * foot eversion - L5 S1 (superficial peroneal)
 * compare between L and R


 * GRADE
 * 0		nil
 * 1		flicker of movement
 * 2		movement cannot overcome gravity
 * 3		movement cannot overcome any resistance
 * 4		movement is weaker than normal
 * 5		normal

Pronator Drift

 * have the patient stand with eyes closed and arms held straight out and hands supinated
 * + → patient cannot maintain this position
 * muscle weakness (pronation and outward drift)
 * UMN lesion (pronation and downward drift)
 * standing problems

Fine Finger Movements

 * ask patient to touch each finger to crease of thumb (show patient how) and speed it up
 * look for right and left differences, slow if UMN lesion

Clonus

 * Ankle or Patellar clonus in UMN Lesion