Figure 4From: The feasibility of measuring the activation of the trunk muscles in healthy older adults during trunk stability exercises Sample ensemble average waveforms. Sample ensemble average waveforms normalized to %MVIC for the 6 abdominal muscles during 3 levels of the exercise progression. [A] Level 1 [B] Level 2 [C] Level 3. Note that three participants did not produce maximal activations during normalization exercises. Coefficients of variation are in Table 4.Back to article page