Fig 1.
Schematic of the isolation module.
The blue, green, and orange outlines mark the sections for channel 1, channel 2, and the common isolated output, respectively.
Fig 2.
Illustration of the experimental protocol; The blue line marks the metronome cues.
(A) cue 1, starting position, 90° knee angle. (B) cue 2, leg extension, 0° knee angle. (C) cue 1, return to starting position, 90° knee angle. The two data traces shown at the bottom are sampled at 2.4 kHz from the VM and VL, respectively.
Fig 3.
Measured frequency response of the new and original amplifier.
Fig 4.
Mean ± SEM of the raw intermuscular coherence of the left and right biceps with left biceps activation only (N = 6).
Fig 5.
60 Hz filtered VM EMG with wavelet filter envelope (top), and 60 Hz filtered VL EMG (bottom).
Traces show EMG data from one subject. Envelope output of the wavelet filter (black trace), midpoints (green dots), and windows (dashed boxes) used for coherence calculation are also shown.
Fig 6.
EMG of concurrent activation pairs (A, C and B, D) and EMG of subsequent activations (A, D, and B, C) used to calculate intermuscular coherence (left). Coherence of concurrent (blue), subsequent (green), and randomized (red) activations of one trial (N = 90 activations) (right).
Fig 7.
Mean ± SEM of (10 subjects, 6 trials, 90 contractions per trial): (A) EMG power (B) active time, and (C) time between peaks of EMG activation.
The asterisk symbol (*) denotes statistical significance (p < 0.05).
Fig 8.
Mean ± SEM (3 trials per condition) coherence of interest.