Electrotherapies are commonly used in the treatment of sporting injuries, occupational injuries and other pain conditions. Ultrasound has been used in physical therapy for decades, but now the new kid on the block, laser seems to be gaining in popularity and may even overtake ultrasound. Here we look at the two different treatment methods, their effects, indications, contraindications and dangers.
Electrotherapy is the use of an electric current to provide therapeutic effects on the body’s tissues. There are many different types of electrotherapy treatments available and their use varies widely between different therapists.
There is some controversy surrounding their use as there is little scientific evidence available to support their efficacy. However, electrotherapy use tends to be justified by therapists who have seen the beneficial effects of using such treatments on a range of different injuries and conditions in a clinical setting.
In general, electrotherapeutic treatments are designed to help:
• Ease pain
• Reduce inflammation
• Decrease swelling
• Increase blood flow
• Increase cellular metabolism
• Break down scar tissue and adhesions
• Increase tissue flexibility
• Decrease muscle spasm
• Increase cell regeneration
• Stimulate muscle contraction
Ultrasound was first used in the 1940’s and is the longest standing form of electrotherapy to still be in regular use. It is still used extensively in physical therapy (physiotherapy, sports therapy, chiropractic and osteopathic) clinics to treat patients with soft tissue injuries.
It is most commonly used to treat superficial localised conditions such as muscle strains, tendinopathies and bursitis. The treatment is applied via a treatment head and using a gel to aid smooth movement and adherence to the skin. Ultrasound tends to be most effective on tissues with a higher collagen density (such as ligaments and tendons), than muscles and cartilage.
Ultrasound therapy uses sound waves which are transmitted into the tissues to have both thermal and non-thermal effects.
Ultrasound therapy cannot be felt; it should not cause pain or tingling sensations. Treatments tend to last anywhere between 3 and 8 minutes, depending on the size and depth of the structure being treated. The treatment head is kept in motion throughout the treatment, to avoid the risk of burns to the underlying tissue.
Laser is an abbreviation of Low-Level Laser Therapy (LLLT) and is a treatment modality which uses red and near infra-red light to improve healing rates, reduce inflammation and decrease both acute and chronic pain.
It was first developed in 1967, but has only more recently been used extensively in injury and pain management clinics. It is used to treat a range of conditions, for example tendinopathies, neuropathic pain and joint pain such as osteoarthritis.
Laser and LED beams stimulate the cells that repair tissues, reduce inflammation and pain. These effects are photochemical, not thermal. LLLT is sometimes also known as ‘cold laser’.
To summarise, Laser can be used on a wider range of injuries and conditions and has fewer contraindications to treatment than ultrasound. Ultrasound poses more of a risk in terms of potential tissue damage, mostly due to the thermal effects and danger of burns. Finally, there is more scientific evidence supporting the use of laser therapy for treating soft tissue injuries.
One study published in the American Journal of Sports Medicine in 2008 (Stergioulas et al) demonstrated a significant improvement in pain levels in those with Achilles tendinopathy when laser was used in conjunction with eccentric strengthening (compared to sham laser and eccentric strengthening).
However, the lack of evidence supporting the use of ultrasound therapy may be due to the wide variation in treatment settings used among different studies which can have dramatic effects on the outcomes. Ultrasound also has a pro-inflammatory effect which may explain why studies looking into the anti-inflammatory effect have shown no effect.
In conclusion, it appears that laser therapy has more applications in treating soft tissue injuries and also poses less risk of cell damage. Whilst many clinicians regularly use ultrasound and have seen positive results in the clinical setting, there is less research to back this up than there is with laser therapy.