Figure 3

Changes in oxy-haemoglobin, deoxy-haemoglobin, total haemoglobin and the tissue oxygenation index in low back muscles during exercise. The values are presented as the mean ± standard error. Significant group effect: * p < 0.05 ** p < 0.001. Different from rest: † p < 0.05 †† p < 0.001.