The effects of intermittent exposure to hyperbaric oxygen for the treatment of an acute soft tissue injury

This study examined the effects of intermittent exposure to hyperbaric oxygen therapy (HBO) for the treatment of delayed onset muscle soreness (DOMS). It is apparent in the literature that a great deal of controversy exists in using this form of therapy to treat tissue injuries. It was hypothesized that subjects exposed to hyperbaric oxygen would recover from DOMS faster than subjects exposed to normoxic air. Sixteen sedentary, female university students participated in the study and were randomly assigned to either an experimental or control group. All subjects performed 300 maximal voluntary eccentric contractions (30 sets of 10 repetitions/minute) of their non-dominant leg (110° - 35° of knee flexion) at a slow speed (30° per second) on the KinCom Dynamometer, to elicit muscle damage and injury. HBO treatments consisted of 100% oxygen for 60 minutes at 2.0 ATA while the control group received 21 % oxygen at 1.2 ATA for the same amount of time. Both groups received treatment immediately after the induction of DOMS and each day after for a period of 4 days [day 2 post-exercise thru day 5 post-exercise]. Dependent variables (perceived muscle soreness, isokinetic strength, quadriceps circumference, creatine kinase (CK), interleukin-6 (IL-6) and malondialdehyde (MDA) were assessed baseline (preexercise, day 1), 4 hours post-exercise (day 2), 24 hours post-exercise (day 3), 48 hours post-exercise (day 4) and 72 hours post-exercise (day 5). MRI [T2 relaxation time/STIR]) was assessed baseline (day 1), 24 hours post-exercise (day 3) and 72 hours post-exercise (day 5). Isokinetic strength (p<0.05) and perceived soreness (p<0.05) indicated significance for injury to the quadricep muscle for both groups but no difference was seen between groups (p=0.102, p=0.571 respectively). Quadricep circumference was measured at the 10 and 20 cm reference point above the superior portion of the patella. The 10cm girth measurement indicated significance (p<0.05) for muscle injury but there was no difference between groups (p=0.815); 20 cm measurement showed no significance (p<0.05) for both within and between groups (p=0.677). No significance was evident for serum CK (p<0.05), both within and between groups (p=0.647). MDA analysis revealed no significance (p<0.05) both within and between groups (p=0.580). Analysis of IL-6 demonstrated no significance (p<0.05) for both within and between groups (p=0.111). Finally, MRI analysis for T2 weighted imaging of the rectus femoris, vastus medius and vastus lateralis showed no statistical significance (p<0.05) between groups for treatment effects (p=0.800, p=0.361, and p=0.806 respectively). Similarly, analysis of the STIR images indicated no statistical significance (p