Dermatomes & Myotomes

Dermatome: an area of skin innervated by a single nerve root

Myotome: a skeletal muscle or group of muscles innervated by a single nerve root

Dermatomes

L2: sweep from L2 over sartorius to mid-inner thigh

L3: sweep from L3 over sartorius to inner knee

L4: sweep from L4 down leg (crossing over at knee region) to big toe

L5: sweep from L5 down leg (crossing over distally to knee - shin area) to toes 2-4

S1: sweep from S1 down back of leg to lateral foot

S2: sweep from S2 down the back of leg to bottom of foot (client is standing so we stop at back of heel)

Myotomes

Test strength in the following joint actions. The joint is placed in mid-range, and the client is asked to meet the resistance of the therapist to perform an isometric contraction for 5 seconds. Any weakness or difference in strength is noted.

L2: Hip Flexion (client is seated - one leg at a time)

L3: Knee Extension (client is seated - both sides at once)

L4: Dorsiflexion (client is seated - both sides at once)

L5: Big Toe Extension (client is seated - both sides at once)

S1: Plantarflexion (client is seated - both sides at once), Eversion (client is seated - both sides at once), Hip Extension (client lies prone - one side at a time)

S2: Knee Flexion (client lies prone - both )