The information provided here is not a replacement for a doctor. You shouldn't use it for the purpose of self-diagnosing or self-medicating but rather so you can have a more informed discussion with a professional TCM practitioner.
Because it is a herb specifically indicated to treat spasmodic pain as can be seen on Liquorice's page.
Its main actions are: Tonifies the Basal Qi and nourishes the Spleen Qi. Clears Heat and dispels toxicity. Moistens the Lungsexpel phlegm and stop coughing. Relieves spasms and alleviates pain. Harmonizes and moderates the effects of other herbs.
Because it is a herb specifically indicated to treat spasmodic pain as can be seen on White Peony Root's page.
Its main actions are: Tonifies the Blood and preserves the Yin. Nourishes the Liver and assists in the smooth flow of Qi. Regulates the meridians and eases the pain.