To increase perspiration diaphoretic herbs are used. This may be done to increase elimination via the skin, or to 'sweat out' a cold, flu, fever or eruptive disease.
Elder flowers
Yarrow herb
Peppermint leaves
Lemon Balm leaves
Catnip herb
Infusion of any of the above, alone or in combination: 1-2 cups taken hot

The diaphoretic action is increased by drinking the infusion as hot as possible and keeping well covered.
To decrease perspiration, and for night sweats:
Sage leaves
Infusion: 1-3 cups per day for 1-3 weeks

Sprains and Fractures
If there is the slightest chance that a bone is fractured, seek professional attention immediately. Once the condition has been properly diagnosed and treated, herbs may be used to reduce the pain and swelling and promote rapid recovery.
To promote the healing of sprains, and to help fractured bones knit together, Comfrey is the principal herb used:
Comfrey root or leaves
Poultice of the fresh plant: apply to the affected area 2- 4 times per day

In some cases a compound formula with additional properties may be more appropriate:
4 parts Comfrey root or leaves (emollient/vulnerary)
2 parts Marigold flowers (antiseptic/vulnerary)
2 parts St John's Wort herb (analgesic/antiseptic/vulnerary)
1 part Ginger root (rubefacient)
Poultice, compress or ointment: apply to the affected area 2-4 times per day