Continuous v/s Pulsed Ultrasound, Combined with Cryotherapy, after Eccentric Exercise DOMS

Abstract

Muscle injuries are one of the gravest injuries in Athletic Care. Using ice for the first 48 hours post injury allows preventing the secondary lesion but does not repair the muscle damage. PURPOSE: To determine which of Continuous or Pulsed Ultrasound (US), combined with Cryotherapy (CRY), is the best treatment to DOMS recovery. METHODS: Twenty four healthy men and women were recruited for a double-blind, controlled trial. Difference with the baseline Pain (dP), mid arm relaxed girth (dMAG), percentage maximal isometric voluntary contraction (d%MIVC), and elbow Range of Motion (dROM) and Total Plasma Creatine Kinase activity (CK) were measured 72 hours before, immediately after, and 24, 48, 72, 96 and 168 hours after a 80% MIVC non-dominant elbow flexors eccentric-exercise protocol (EEP). Subjects were randomly assigned in one of the follow groups: Control-Control (CON-CON) without EEP and any treatment (n=6), Control-Exercise (CON-EXC) with EEP and no kind of treatment (n=6), USC-C with EEP and Continuous US treatment plus CRY (n=6) and USC-P with EEP and Pulsed US treatment plus CRY (n=6). The CRY was a 30 minutes cold pack protocol applied immediately after, 24 and 48 hours after the EEP; while the US was applied by 5 minutes each 20 cm2, 24, 48, 72 and 96 hours after the EEP, with a 0.8 W/cm2 fixed intensity for both US modalities, but a 20% Duty Cycle for the Pulsed US and 100% for the Continuous (SATA= 0.16 & 0.8 W/cm2 respec.). RESULTS: No statistical differences in CK levels were observed between treatment groups and CON-CON group at any time, while CON-EXC group shows significant higher levels 96 hours post EEP than CON-CON group (1309.82 ± 1261.80 v/s 131.90 ± 67.70 U/L, p<0.05) and 168 hours post EEP than CON-CON, USC-P and USC-C groups (1131.00 ± 856.81 v/s 98.10 ± 53.47, 394.95 ± 617.12, 125.00 ± 76.15 U/L respectively, p<0.05). The USC-C group recovered the force faster (v/s CON-CON, 48 hours post EEP, p>0.05) and rose it significantly higher than USC-P 168 hours post EEP (d%MIVC = 38.18 ± 45.68 v/s −18.70 ± 43.01%, p<0.05). Both treatment groups showed some significant effects on dP, dMAG and dROM when compared with CON-EXC group, but 168 hours post EEP. CONCLUSIONS: These results show that Continuous US appears to be more effective than Pulsed US, combined with CRY, recovering DOMS; and confirm that the effects of US are dosage related.