BACKGROUND: It is well known that reducing tissue temperature changes sensory and motor nerve conduction. However, few studies have compared the effect of different cold modalities on nerve conduction parameters. Objective: The purpose of this study was to compare the effects of ice pack, ice massage, and cold water immersion on the conduction parameters of the sural (sensorial) and tibial motor nerves. Design: An experimental study was conducted in which the participants were randomly assigned to 1 of 3 intervention groups (n=12 per group). Independent variables were cold modality and pre- and post-cooling measurement time. Dependent variables were skin temperature and nerve conduction parameters. Methods: Thirty-six people who were healthy, with a mean (SD) age of 20.5 (1.9) years, participated in the study. Each group received 1 of the 3 cold modalities, applied to the right calf region for 15 minutes. Skin temperature and nerve conduction parameters were measured before and immediately after cooling. Results: All 3 modalities reduced skin temperature (mean=18.2 degrees C). There also was a reduction in amplitude and an increase in latency and duration of the compound action potential. Ice massage, ice pack, and cold water immersion reduced sensory nerve conduction velocity (NCV) by 20.4, 16.7, and 22.6 m/s and motor NCV by 2.5, 2.1, and 8.3 m/s, respectively. Cold water immersion was the most effective modality in changing nerve conduction parameters. Limitations: The cooling area of the ice massage and ice pack was smaller than that of the cold water immersion. The examiner was not blinded to the treatment group. The population included only participants who were healthy and young. Conclusions: All 3 modalities were effective in reducing skin temperature and changing sensory conduction at a physiological level that is sufficient to induce a hypoalgesic effect. The results suggest that cold water immersion, as applied in this study, is the most indicated modality for inducing therapeutic effects associated with the reduction of motor nerve conduction.
Wiltshire EV, Poitras V, Pak M, Hong T, Rayner J, Tschakovsky ME. Massage impairspostexercise muscle blood flow and 'lactic acid'removal. Medicine and Science in Sports and Exercise. 2010;42(6):1062-71
This study tested the hypothesis that one of the ways sports massage aids muscle recovery from exercise is by increasing muscle blood flow to improve 'lactic acid' removal. Methods: Twelve subjects performed 2 min of strenuous isometric handgrip (IHG) exercise at 40% maximum voluntary contraction to elevate forearm muscle lactic acid. Forearm blood flow (FBF; Doppler and Echo ultrasound of the brachial artery) and deep venous forearm blood lactate and H+ concentration ([La-], [H+) were measured every minute for 10 min post-IHG under three conditions: passive (passive rest), active (rhythmic exercise at 10% maximum voluntary contraction), and massage (effleurage and petrissage). Arterialized [La-] and [H+] from a superficial heated hand vein was measured at baseline. Results: Data are presented as mean +/- SE. Venoarterial [La-] difference ([La-]v-a) at 30 s of post-IHG was the same across conditions (passive = 6.1 +/0.6 mmol.L-1, active = 5.7 +/- 0.6 mmol.L-1 , massage = 5.5 +/- 0.6 mmol.L-1, NS), whereas FBF was greater in passive (766 +/- 101 mL.min-1) versus active (614 +/- 62 mL.min-1, P = 0.003) versus massage (540 +/- 60 mLmin-1, P < 0.0001). Total FBF area under the curve (AUC) for 10 min after handgrip was significantly higher in passive versus massage (4203 +/- 531 vs 3178 +/- 304 mL, P = 0.024) but not versus active (3584 +/- 284 mL, P = 0.217). La- efflux (FBF x [La-]v-a) AUC mirrored FBF AUC (passive = 20.5 +/- 2.8 mmol vs massage 14.7 +/- 1.6 mmol, P = 0.03, vs active = 15.4 +/- 1.9 mmol, P = 0.064). H+ efflux (FBF x [H=]v-a) was greater in passive versus massage at 30 s (2.2 + 0.4e-5 vs 1.3 +/- 0.2e5 mmol, P < 0.001) and 1.5 min (1.0 +/- 0.2e-5 vs 0.6 +/- 0.09e-5 mmol, P = 0.003) after IHG. Conclusions: Massage impairs La-and H+ removal from muscle after strenuous exercise by mechanically impeding blood flow.