Ice freezes pain? A review of the clinical effectiveness of analgesic cold therapy.

Among the physical treatments to reduce pain, ice has had its place for many years. Experience tells us that ice has a strong short-term analgesic effect in many painful conditions, particularly those related to the musculoskeletal system. Serial applications may also be helpful. The scientific evidence from clinical trials is, however, fragmentary. This applies both for acute and serial cold-induced analgesia. The mechanisms by which cryotherapy might elevate pain threshold include an antinociceptive effect on the gate control system, a decrease in nerve conduction, reduction in muscle spasms, and prevention of edema after injury. It is concluded that ice may be useful for a variety of musculoskeletal pains, yet the evidence for its efficacy should be established more convincingly.