NOTE: THESE SUMMARIES ARE OF HISTORICAL INTEREST ONLY AS THE REFERENCED COCHRANE REVIEWS ARE NOW OUTDATED
- Hyperbaric oxygen therapy: Nine trials
Participating in sport and exercise commonly causes muscle soreness and injury. Muscles, tendons and ligaments are the soft tissues of the musculoskeletal body system. The causes of soft tissue injuries may also be from acute traumatic impact, repetitive strain and overuse, or muscle injury induced by unaccustomed exercise.
The soreness may not be immediate but occurs in the next few days. These symptoms may be caused by lactic acid accumulation, muscle spasms, connective tissue damage and inflammation. They are self limiting and resolve by themselves over a few days.
Accepted treatments include rest, reducing the swelling by applying ice or raising the limb, massage, taking painkillers and non-steroidal anti-inflammatory agents, stretching or further exercise, surgery and rehabilitation. Treatment is aimed at restoring pain-free function to resume normal activities in the shortest possible time without further injury.
HYPERBARIC OXYGEN THERAPY FOR DELAYED MUSCLE SORENESS AND INJURY
Hyperbaric oxygen therapy (HBOT) involves people breathing pure oxygen in a specially designed chamber that allows the pressure to be raised. Increasing the supply of oxygen to a soft tissue injury could possibly speed recovery and has been used as a therapy by sporting clubs.
Typically, treatments involve being in a pressurised chamber (between 1.5 and 3.0 ATA) for between 30 minutes and two hours, once or twice daily. This can cause visual disturbances including temporary worsening of shortsightedness, claustrophobia and other adverse effects including damage to the ears, sinuses and lungs, from the effects of pressure (barotrauma). The great majority of people experiencing visual disturbances recover over a period of days to weeks. Oxygen in high doses is toxic to normal tissue, in particular the brain and lungs so a tight schedule has to be kept to. Serious adverse events are rare but possible.
What the synthesised research says
No clear benefit was evident for hyperbaric oxygen therapy on soft tissue ankle sprains, knee ligament injuries or delayed onset muscle soreness.
People with ankle sprains or knee ligament injuries had similar time to recovery, functional outcomes, pain, or swelling with or without HBOT some one to three days following injury. This conclusion is based on only two small trials comparing HBOT with sham therapy on soft tissue ankle sprains (32 participants) and knee ligament (medial collateral) injuries (14 participants).
We found no evidence that HBOT helped young healthy people with muscle injury following unaccustomed exercise (in seven trials where it was experimentally induced), but rather people might have had slightly more pain two days after the exercise when given HBOT.
How it was tested
The researchers made a thorough search of the medical literature and found nine trials involving a total of 219 participants. A fifth of participants were female. The trials were published between 1996 and 2003, and from centres in Canada, the US and Europe. The number of participants in each trial ranged from 12 to 49.
Most trials randomly assigned participants to receive hyperbaric oxygen or a sham therapy within four hours after the exercise session and, in two trials approximately 24 hours after exercise.
Both the dose of oxygen per treatment session and for the total course of treatment varied between trials. Trialists used between 2.0 atmospheres absolute (ATA) and 2.5 ATA as a maximum oxygen pressure and the total number of individual treatment sessions varied from three to 10.
In general, study quality was assessed as fair to high with regard to methodology.
Side effects and general cautions
No trial reported complications with HBOT. One trial excluded those with an upper respiratory tract infection or a past history of claustrophobia from participating.
Trials were not consistent in how they reported the measures of soft tissue damage (outcomes) and reporting of full data.
Fellowes D, Bennett M, Best TM, Babul S, Taunton J, Lepawsky M. Hyperbaric oxygen therapy for delayed onset muscle soreness and closed soft tissue injury. The Cochrane Database of Systematic Reviews 2005, Issue 4. Art. No.: CD004713.pub2. DOI: 10.1002/14651858.CD004713.pub2.