Myotomes, Somatic Reflexes & Dermatomes

Question 1

Myotome vs dermatome

Answer 1

Myotome- group of muscles innervated by a single spinal nerve
Dermatome- an area of skin supplied by a specific spinal nerve

Question 2

Upper limb neuro exam

Answer 2

• inspection- SWIFT (scars, wasting, involuntary movements, fasiculations, tremor)
• hold hands out with eyes closed and turn them over
• tone- move arms about
• power- chicken wings (shoulder abduction and abduction), boxing (elbow extension and flexion), motorbike (wrist extension and flexion), mummy (finger extension and flexion), spread fingers (finger abduction), waiter with thumbs up (thumb abduction)
• reflexes- biceps reflex, thumb needed (above elbow crease), triceps reflex (above elbow on the back), supination reflex, thumb needed (radius)
• sensation- cotton wool across the dermatome map doing one side after another to compare, tuning fork on proximal bony point of thumb, proprioception of thumb grabbing the sides
• coordination- finger to nose, palm flip test with eyes closed

Question 3

Lower limb neuro exam

Answer 3

• inspection- SWIFT (scars, wasting, involuntary movements, fasiculations, tremor)
• gait- stand up with arms crossed, walk, heel toe, tip toe, heel, stand with eyes closed
• tone- shake legs and lift
• power- lift and lower leg (hip flexion and extension), squeeze and separate hips (hip abduction and adduction), kick and pull bent leg (knee extension and flexion), door hold and ballet feet (ankle dorsilfexion and plantarflexion), big toe push and pull, ankle inversion and eversion
• reflexes- knee jerk, ankle jerk, plantar reflex
• sensation- cotton wool across dermatomes, tuning fork on big toe, proprioception of big toe
• coordination- ankle on knee then down shin, tap feet against hands