Cryotherapy
Commonly used to treat pain conditions. Most forms of cryotherapy (eg, ice, cold packs, cold whirlpool baths, cryotherapy-compression units, vapocoolant spray) used as passive physical modalities (these include cryotherapy, heat, and electrical stimulation) of the management and rehabilitation of both acute and persistent pain conditions, provide transfer of thermal energy by conduction, with the exception of vapocoolant sprays (evaporative cooling) and whirlpool baths (convective cooling). The physiologic effects of cold application include immediate vasoconstriction with reflexive vasodilation, decreased local metabolism and enzymatic activity, and decreased oxygen demand. Cold decreases muscle spindle fiber activity and slows nerve conduction velocity; therefore it is often used to decrease spasticity and muscle guarding.