Icing injuries may delay healing and prolong pain recovery

Icing a sprained ankle or sore muscle, long used to reduce pain and swelling, may in the longer run delay recovery and prolong pain, new research suggests.

In a preclinical study published in Anesthesiology, McGill University researchers found that even though cryotherapy (icing) eased pain in the short term, recovery time was more than doubled in some cases.

These results highlight a paradox: treatments that reduce inflammation and relieve pain in the short term may, in some cases, interfere with the biological processes required for full recovery."

Lucas Lima, lead author, research associate at the Alan Edwards Centre for Research on Pain

The findings add to a growing body of research questioning the long-term benefits of common anti-inflammatory strategies, said Lima. Previous studies have shown that medications such as acetylsalicylic acid (Aspirin) can also extend the duration of pain, and animal research has suggested icing may delay tissue repair.

The new study provides, for the first time, direct evidence that icing can also affect the duration of pain itself, based on experiments with mice mimicking inflammatory and exercise-related injuries.

Icing is commonly used as part of the RICE protocol, a standard approach to managing injuries that includes rest, ice, compression and elevation. It is widely used by athletes, clinicians and in everyday injury care, but there is limited evidence for its long-term benefits, said the researchers.

"Our results suggest we need to better understand when anti-inflammatory strategies are helpful and when they are not," said senior author Jeffrey Mogil, James McGill Distinguished Professor and E. P. Taylor Chair in Pain Studies.

He emphasized the results are not yet directly applicable to humans. A clinical trial is underway to test whether the same effect appears in patients recovering from procedures such as wisdom tooth removal.