Cryotherapy for treating soft tissue injuries in sports medicine: a critical review

Key points

1. 01No randomised controlled trial in humans has tested cryotherapy for acute soft tissue healing
2. 02The only eligible human study (a pilot RCT on calf muscle ruptures) found no difference in pain, function, or recovery time
3. 03Animal studies suggest cryotherapy may delay muscle fibre regeneration and increase collagen scarring after large injuries
4. 04For minor muscle injuries, some animal data suggest cryotherapy could limit injury expansion and aid early recovery
5. 05Cryotherapy is supported only for short-term pain relief in the first 6 hours; use beyond 12 hours warrants caution

How it was conducted

Design

Critical review with systematic literature search (PRISMA)

Databases

Medline and Web of Science, no date filter

Articles screened

452 studies screened

Eligible studies

1 human study and 26 animal studies met inclusion criteria

Eligible human study

One pilot RCT on ice pack treatment of gastrocnemius (calf) muscle ruptures

Animal models

Rodents and rabbits using ice packs, cold water immersion, or cold saline perfusion for muscle, tendon, and ligament injuries

What they found

• Only 1 human study met eligibility criteria; it showed no difference between cryotherapy and control for pain, functional capacity, or convalescence time (Prins et al, pilot RCT on calf muscle rupture)
• To detect a 10% difference in full recovery rate a total of 396 participants would have been required (power=0.80; alpha=0.05)
• In rats, post-injury cryotherapy limited postinjury increase in paw volume up to 4-6 hours
• Ice application (1x20 min immediately post-injury) induced a higher increase in collagen fibre area than control up to 28 days after injury in mice and rats (Takagi et al)
• A single 20 min ice application delayed recovery of muscle fibre cross-sectional area in mice and rats across multiple studies (Kawashima, Miyazaki, Takagi)
• In a limited necrosis model (~10% of muscle) in rats, multiple icing sessions facilitated muscle recovery and earlier accumulation of activated satellite cells (Nagata et al)
• 30 min of cryotherapy post-tendon injury reduced prostaglandin E2 (PGE2) levels by 46.3% in patellar tendons and 50.85% in Achilles tendons within the first 3.5 hours in animals (Zhang et al)
• A meta-analysis of 7 studies estimated cryotherapy has a role in postoperative pain control but without improvements in range of motion or drainage

Limitations

• No RCT exists in humans for acute soft tissue healing; evidence base relies almost entirely on animal studies
• Animal injury models (crush, injection, freezing) differ substantially from typical human sports injuries in injury severity and haematoma formation
• Optimal dosing parameters (timing, duration, temperature) for cryotherapy in humans remain unknown and untested
• Results across animal studies are highly variable due to differences in cooling method, injury model, animal species, and outcome measures

Why it matters

For patients

If you are icing a sports injury, it is reasonable for the first few hours to reduce pain, but continuing ice treatment for days is not supported by evidence and may potentially slow tissue repair.

For clinicians

Cryotherapy can be recommended for short-term analgesia in the acute phase (up to 6 hours post-injury), but routine prolonged use beyond 12 hours should be applied cautiously given animal data suggesting impaired regeneration; human RCTs are urgently needed.

For readers

This review exposes a major evidence gap: one of the most widely practised sports medicine interventions has never been rigorously tested in humans for its effect on healing, and the available animal literature raises genuine safety questions about prolonged use.