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We read with great interest the recent work of Dr. Algafly und Dr.
George regarding the effect of sole cryotherapy on nerve conduction
velocity, pain threshold and pain tolerance in healthy volunteers. We
would like to thank the authors for their important contribution, but we
would further appreciate commenting on some issues raised by the authors.
The ankle was focussed in this study usi...
The ankle was focussed in this study using crushed ice, which was
applied on average for 26min (range 20-31min) to achieve a skin
temperature of 10°C. For each 1 degree fall in skin temperature, the
authors found a decrease of sensory nerve conduction velocity of 0.4m/s
among their subjects. We fully agree with the authors that further studies
are mandatory. Especially, since the RICE regimen incorporates not only
cryotherapy, but also compression, elevation and rest, we do not know to
what extent sole cryotherapy works in this mosaic. Actually, besides the
neurological point of view, we found tissue microcirculation to be
modified tremendously following sole cryotherapy, if applied intermittent
for 3x10min . Among thirty volunteers, superficial capillary blood
flow was reduced from 42 relative units (rU) to 6rU in the 1st, 5rU in the
2nd and 3rU in the 3rd cryotherapy period (-65%, p=0.0003) with no
significant capillary hyperaemia. Superficial tendon oxygen saturation
dropped significantly from 43% to 26/18/11% (p=0.0004) after repetitive
cryotherapy with persisting increase of tendon oxygenation during
rewarming (51/49/54%, p=0.077) up to +27% of the baseline level. Relative
postcapillary venous tendon filling pressures were favourably reduced from
41+/-11rU to 31/28/26rU (-36%, p=0.0004) superficially and deep from 56+/-
11rU to 45/46/48rU (-18%, p=0.0001) during cryotherapy facilitating
capillary venous clearance. Therefore a facilitation of postcapillary
venous outflow is associated with sole cryotherapy applied for 3x10min only
which might have a direct effect on pain level as well due to reduced
tissue tension. This data is supported by a recent controlled laboratory
study stating that prolonged cooling reduces microvascular dysfunction,
inflammation, and structural impairment .
The intermittent cryotherapy seems to be favourable to use, since the
superb Bleakley study, where they randomized 44 sportsmen and 45 general
public subjects with moderate ankle sprains for either 20min of single
cryotherapy or intermittent cryotherapy for 10 minutes with 10min of
rewarming and a second 10min of cryotherapy and 10min of reperfusion with
this cycle being repeated every two hours . Subjects treated with the
intermittent protocol had significantly (p<0.05) less ankle pain on
than those using a standard 20 minute protocol; however, one week after
ankle injury, there were no
significant differences between groups in terms of function, swelling, or
pain at rest. Therefore based on these results it would be appropriate to
examine the effects of only 10minutes of cryotherapy in an intermittent
regiment regarding the nerve conduction velocity to elucidate its value.
25 or even 30minutes of continuous ice application are in our personal
view not that effective at least both, from a microcirculatory and a
clinical point of view [1,2] and might lead to an adverse reaction, such
as a frostbite at the gym .
 Knobloch K, Grasemann R, Spies M, Vogt PM. Intermittent
KoldBlue(R) cryotherapy of 3x10min changes mid-portion Achilles tendon
microcirculation. Br J Sports Med 2006, Nov 30.
 Schaser KJ, Disch AC, Stover JF, Lauffer A, Bail JH, Mittlmeier
T. Prolonged superficial local cryotherapy attenuates microcirculatory
impairment, regional inflammation, and muscle necrosis after closed soft
tissue injury in rats. Am J Sports Med 2007;34(1):93-102.
 Bleakley CM, McDonugh SM, MacAuley DC. Cryotherapy for acute
ankle sprains: a randomised controlled study of two different icing
protocols. Br J Sports Med 2006;40:700-5.
 O'Toole G, Rayatt S. Frostbite at the gym: a case report of an
ice pack burn. Br J Sports Med 1999;33(4):278-9.