Should Ice Just be for Our Gin and Tonic? By Dr David Marlin
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any professionals will likely be aware over the anti-RICE (rest, ice, compression, elevation) movement that has been gaining publicity for the past perhaps 15-20 years. But even so, the most widely used method in human medicine/sports medicine for the treatment of acute soft tissue injury is still RICE. In the equestrian world, cold or cryotherapy is still widely used and there does not appear to be much in the way of campaigning against its use as there is in human medicine. So is the difference because we know something that those dealing exclusively with human patients don’t know or is it just that we don’t yet have the studies to show its at best ineffective or at worst harmful and actually slowing recovery from injury? Perhaps the first thing to examine is the way in which cryotherapy could be used with horses. The first and most obvious is in acute injury. Here the use of cold has the effect of reducing the inflammatory response and reducing pain. There have been suggestions that reducing inflammation in acute injury is detrimental as the inflammatory response is part of the repair process. The jury still seems to be out on this but this is certainly a core argument against the RICE protocol; that is inflammation is good and should not be controlled. In this context, these two quotes are pertinent. “Acute inflammation is an important part of the healing process after musculoskeletal injury, but unless it is controlled early, it can significantly hamper rehabilitation.” (Baumert, 1995). “The objective of RICE is to stop the injury-induced bleeding into the muscle tissue and thereby minimise the extent of the injury.” Jarvinen et al. (2007). So the key aspects of using ice or RICE are about limiting but not abolishing inflammation and reducing the extent of the effect of an injury into surrounding (uninjured) tissue. The second and equally important aspect of cryotherapy in acute injury is the analgesic benefit. In cases of moderate to severe injury it may be some time before a vet can see a horse and administer anti-inflammatory medication and these still take some time to produce a significant effect, so in that period cryotherapy can provide a degree of analgesia.
I believe the ideal is actually likely somewhere in between and I think this may be where the arguments have become polarised and extreme. From my perspective It’s not an argument about whether to cryotherapy or NOT, it should be a discussion about how much cryotherapy is useful and in what situations.
The other use of cryotherapy is prophylactically in relation to regular training and competition when there is no obvious injury. In the horse this is particularly relevant to the feet, the fetlock and knee joints and the flexor tendons. Training or competing on hard ground can lead to soreness in the feet and joints which can be treated with cryotherapy following exercise. Similarly, older horses with arthritic changes in their joints can be made more comfortable after exercise with acute cryotherapy. With respect to tendons and ligaments, particularly those of the lower limbs, we are aware that these are a very common site of injury and that the injuries are in the main the result of accumulation of lowgrade damage over months and years of use. The temperatures within these tendons are also some of the highest in the body and this enhances any inflammatory effect. Is this natural? I would argue the domesticated horses tendons are not ideally designed to cope with the temperatures that they reach during training and competition. The temperature at the end of exercise is a combination of intensity and duration. In the wild horses do not canter and gallop for the same durations as we ask in training and competing and
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so likely their tendons do not reach extremely high temperatures which lead to inflammation and degradation of the tendon matrix. For this reason, I believe that cooling after exercise is an important tool for tendon longevity. To return to the controversy over the use of RICE in human medicine/ sport. There is evidence from published peer-reviewed studies that reducing inflammation is beneficial in many circumstances. It’s not that all evidence supports not adopting the use of cold. In addition, this is not about blocking inflammation entirely, which is unachievable, but about a moderated inflammatory response as a degree of inflammation is clearly part of the repair process. Use of cryotherapy in the horse has to also be considered in the light of a number of factors: (1) We cannot actually adopt RICE – we can only partially rest (non-weight bearing is not an option), we can ice, we can compress, but we cannot elevate (2) Ice is used on the lower limbs of horses not only for tendon and ligament but also for joint and for the feet (e.g. concussive laminitis, reducing the severity of laminitis from other cause, etc) (3) Tendon and ligament injuries are the most common lower limb injury in mature horses (e.g. Murray et al. 2006), particularly SDFT tendinitis. Consensus is now that the majority of these injuries are as a result of accumulated (chronic) low-level damage/repeated insults as opposed to isolated catastrophic events. The wild horses spend the majority of time walking, whilst domesticated horses experience significantly greater periods of trot, canter and gallop i.e. an exercise regimen they did not evolve for (4). Horse tendons reach very high temperatures during exercise – 45°C (Wilson and Goodship, 1994). There is clear evidence from two unrelated studies that hyperthermia (at the temperatures recorded in vivo) reduces equine tendon cell viability in vitro (Birch et al. 1997; Hosaka et al. 2006). (6) “In conclusion, while temperatures experienced in the central core of the SDFT in vivo are unlikely to result in tendon cell death, repeated hyperthermic insults may compromise cell metabolism of matrix components, resulting in tendon central core degeneration” Birch et al. (1997). So if you are going to use cryotherapy either for acute injury or on the limbs after training or competition, which methods are most effective and how long should they be used for? I recently
