When treating musculoskeletal injuries, chiropractors often face the key question of when to use heat vs ice therapy. Understanding the benefits of ice and heat therapy can significantly impact a patient's healing journey. This blog breaks down evidence-based guidance on heat and ice therapy, highlighting when each can be most beneficial.
When to Use Ice vs. Heat for Musculoskeletal Injuries
Heat and cold therapy both play valuable roles in managing pain and promoting healing. However, their mechanisms and effects differ. Selecting the right modality depends on understanding these mechanisms and the specific injury or condition.
Mechanism of Action and Benefits of Cold Therapy
Cold therapy, or cryotherapy, is commonly used immediately following an acute injury to reduce inflammation and limit tissue damage. (1) This method is particularly beneficial for soft-tissue injuries such as sprains, strains, and swelling, as it decreases blood flow, lowers metabolic demand, and reduces tissue temperature, all contributing to its effectiveness. (2) Ice therapy benefits are primarily achieved through the following physiological mechanisms:
Pain Relief: Ice numbs the affected area, temporarily suppressing nerve activity (NCV) and muscle spasms. (1,3)
Reduced Swelling: Ice minimizes fluid buildup in the injured area through vasoconstriction of arterioles and capillaries, effectively controlling swelling. (1,2)
Reduced Immune Cell Activity: Cold therapy decreases the presence of leukocytes, granulocytes, and macrophages—key immune cells involved in inflammation. (2)
Limiting Secondary Injury?: Many clinicians and some researchers believe that ice therapy can limit subsequent tissue damage and potentially support muscle regeneration by reducing the immediate pro-inflammatory response. This belief is primarily based on animal studies, which suggest that early application of ice can help control inflammation and minimize further injury within the first 6-12 hours. (2,3) However, a critical review published in the October 2024 British Medical Journal found no conclusive evidence from human studies that cryotherapy effectively limits secondary injury or promotes tissue regeneration. (4)
When to Use Ice Therapy
Acute MSK Injuries- i.e., sprains, strains, contusions, etc. Cold therapy has proven to be most beneficial for controlling excessive swelling within the first 6-12 hours post-injury. (1-3)
Migraine Headaches: Using ice for migraines can provide relief. (5-7) Applications include cold-gel headbands or caps placed on the forehead and wraps applied to the neck to target the carotid arteries. (7)
Acute Rheumatologic Flare-Ups: While there is no research consensus, ice therapy is generally considered beneficial for reducing inflammation in acute rheumatologic flare-ups, particularly in cases of gout. (8-9,38)
Post-Knee Arthroplasty: Studies indicate that cold compression therapy after knee replacement surgery can improve outcomes, such as better pain relief, compared to other treatment methods. (10,11)
Cooling Controversy: Rethinking Ice for Injury Recovery
The RICE protocol (Rest, Ice, Compression, Elevation), introduced by Dr. Gabe Mirkin in 1978 in The Sports Medicine Book (12), was long considered the gold standard for treating acute injuries. However, Dr. Mirkin has since revised his stance, suggesting that ice should be used cautiously post-injury. (13) Emerging data indicates that while ice therapy can reduce pain and control swelling in the immediate aftermath of an injury, prolonged cooling (beyond 6-12 hours) may actually hinder recovery by delaying tissue repair and increasing scar tissue formation. (3,4,14-17)
Rather than aiming to eliminate inflammation, current recommendations focus on regulating and optimizing the inflammatory response to support recovery. Recent evidence has led practitioners to shift from RICE to the PEACE & LOVE approach, which emphasizes early protection, elevation, avoiding anti-inflammatories, compression, and education, followed by (controlled) loading, optimism, vascularization, and exercises. (2)
The new cold, hard truth about ice therapy vs heat therapy: While ice likely remains helpful in the first 6-12 hours post-injury to alleviate acute symptoms, it may act as a barrier to healing if used too long, potentially leading to tissue damage and even nerve injury. (2,4) Consequently, ice is now considered best for short-term pain management rather than a primary strategy for ongoing recovery from musculoskeletal injuries.
Practical Application of Ice Therapy
Types of cold therapy: Ice pack therapy, migraine ice cap, bagged ice, compressive cryotherapy devices, immersion ice bath therapy, or whole-body cryotherapy chambers. (11)
The optimal temperature of ice therapy: Undefined and dependent on the amount of internal and external insulation. Somewhere between cool water and nearly 0 degrees Celsius for a chemical instant ice pack (which carries a frostbite risk).
How long to apply ice therapy: 10-20 minutes. (2,18) When using an ice pack, patients may progressively feel cold, followed by burning, aching, and finally numbness (CBAN). Remove the ice pack if numbness occurs.
Contraindications for Ice Therapy: Ice therapy should be avoided in cases of impaired circulation, Raynaud’s disease, cryoglobulinemia, hemoglobinuria, peripheral vascular disease, hypersensitivity to cold, cold urticaria, Complex Regional Pain Syndrome (CRPS), or skin anesthesia. It is also contraindicated over regenerating nerves, open wounds, or burns, as it can worsen tissue damage or lead to hypothermia. Whole-body immersion and cryotherapy chambers should be used with caution to avoid potential side effects like hypotension, tachycardia, and syncope. Proper screening and precautions are essential, especially with prolonged exposure or specific applications like ice massage or cold packs. (8,19-21)
Mechanism of Action and Benefits of Heat Therapy
Heat therapy is particularly useful in managing chronic or subacute musculoskeletal pain. It increases blood flow, improving tissue elasticity, muscle flexibility, and oxygenation. Heat also activates thermoreceptors, blocking pain signals to the brain and providing relief for conditions like low back pain. (1,22) Heat therapy benefits are primarily achieved through the following physiological mechanisms:
Pain Relief: Heat therapy activates temperature-sensitive nerve endings (thermoreceptors), which help block pain signals by inhibiting nociceptive processing. Additionally, the pressure concurrently used in some heat applications can stimulate proprioceptors, further reducing pain signals. (22)
Increased Blood Flow and Metabolism: Heat application boosts blood flow and metabolic activity, delivering more oxygen and nutrients to tissues. This increase in circulation supports muscle function and may enhance strength and mobility. (1,22)
Enhanced Muscle Flexibility and Tissue Elasticity: Heat improves muscle flexibility and connective tissue elasticity, aiding mobility and reducing stiffness. (1,22)
Improved Muscle Strength and Activation?: Heat therapy increases blood flow, enhancing the supply of oxygen and nutrients to muscles. This boost in metabolic activity supports greater muscle fiber activation, potentially improving muscle strength and function. (22)
When to Use Heat Therapy
Lower Back Pain: Heat therapy is recommended for managing non-specific low back pain in acute, sub-acute, and chronic phases. Clinical practice guidelines from the Annals of Internal Medicine support heat therapy for reducing pain and improving function across these stages. (26) Studies indicate that heat therapy provides short-term relief from pain and disability. (22-26) and that combining heat therapy with other treatments may even improve muscle strength in chronic lower back pain. (27)
Non-acute Mechanical Pain: Heat therapy is beneficial for managing sub-acute and chronic mechanical nociceptive pain conditions, including tendinosis and osteoarthritis. It is also recommended for strains and sprains during the sub-acute and chronic rehabilitation phases once the acute phase has passed.
Pre-Workout: Applying heat before exercise can enhance physical function, range of motion, and flexibility, reducing the risk of muscle strain or stiffness. Research has shown that using low-level heat therapy a few hours before intense exercise provides pain relief and improves movement, helping to prevent muscular damage during activity. (28,29)
Delayed Onset Muscle Soreness (DOMS): Evidence is mixed on whether ice or heat is best for DOMS relief. Some studies recommend starting with ice and then switching to heat. (30) A review of over 50 studies suggests that heat provides the most effective pain relief in the first 24 hours post-exercise, with cryotherapy being more effective after 48 hours. (31) Some research finds heat more beneficial overall than cold therapy for DOMS (1); other studies suggest both methods are similarly effective. (32)
Dysmenorrhea: Most experts (78%) agree that heat therapy may be used to relieve pain associated with dysmenorrhea. (22)
Practical Application of Heat Therapy
Types of heat therapy: Moist heat therapy (Hydrocollator®, etc), heating pads, heat wraps, immersion/ hot tub
Optimal Temperature for Heat Therapy: Most experts agree that 40°C (104°F) is an effective and safe temperature for superficial heat therapy. (22,25,28,33-35) Studies have shown that increasing tissue temperature to 38°C, 40°C, and 42°C in the trapezius muscle increases local blood flow by 27%, 77%, and 144%, respectively. (36)
How long to apply heat therapy: The time needed to reach these temperatures varies by body composition; for example, 2 cm of subcutaneous fat may take up to 30 minutes to achieve the desired therapeutic effect. (22)
Contraindications for Heat Therapy: Heat should be avoided for acute pain following trauma as it can increase inflammation in acute inflammatory conditions. (37) Heat therapy also requires intact skin and should be used cautiously or avoided entirely in individuals with active autoimmune conditions, skin disorders (i.e., herpes zoster), infections, malignancies, inflammatory diseases including inflammatory joint pain, pregnancy, or neurological conditions that may alter peripheral sensitivity, such as multiple sclerosis, ALS, spinal injuries, and diabetes. Additionally, heat therapy is not recommended during pregnancy. (22,37)
Key Takeaways for Clinical Practice
By understanding the principles and consulting current research, chiropractors can offer patients an evidence-based approach to using heat and ice therapy. Such strategies can not only enhance patient comfort but also promote long-term healing.
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