Hi all,

I perform Long-Term EMG study. I use BioStamp as my main data collection platform. For some reason, lots of my data were corrupted when I use the BioStamp electrodes. There are always a large spike before each recorded muscle activation. ( I attached a picture of the EMG data.) My filtering process is High pass (20Hz), Rectified and Low Pass (15Hz). Signal is collected in 1000 Hz

My question is what causes them and how I can remove them.

My muscle placement is Bicep, Tricep (lateral), ECR and FCU
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