Jerking sinews and twitching flesh

From On Cold Damage (伤寒论 shāng hán lùn, biàn tài yáng bìng zhèng bìng zhì). Spasmodic jerking of the sinews and flesh.

Insufficiency of blood and liquid (血津不足 xuè jīn bù zú): Jerking sinews and twitching flesh mostly arises when copious sweating damages yáng, causing blood vacuity and wear on liquid that deprives the sinews of nourishment.

Medicinal therapy: Use Four Agents Decoction (四物汤 sì wù tāng).

Damage to yáng (伤阳 shāng yáng): Less commonly the cause is damage to yáng by cold-damp in cold damage, preventing water qì transformation.

Medicinal therapy: Use True Warrior Decoction (真武汤 zhēn wǔ tāng).