Normalization to an isometric MVC that is standardized but not matched to the task under investigation. This method includes:

• Non-specific isometric maximal voluntary contraction: The peak EMG amplitude from a maximal isometric voluntary contraction, usually obtained from a mid-range joint angle (not as the task of interest).
View full definition

• Muscle synergy will include the muscle(s) that might be more relevant for the task.
• It’s more practical to do separated isometric tasks for different muscles than for complex tasks.

• Because normalising to MVC will bias the muscle synergy toward the muscle(s) with the higher %MVC, then muscles with a low percentage of activity will have little impact on the synergy and might not be included (their weights would be zero or close to zero).

• Because normalising to MVC will bias the muscle synergy toward the muscle(s) with the higher %MVC, then muscles with a low percentage of activity can have a small weight in the synergies.
• No information about relative activation level can be deduced by the weights of the muscles within each synergy.
• If the MVC cannot be reliably performed (e.g., because of pain or inability of the participant to elicit a maximum contraction), then differences in each muscle weight and temporal profile need to be carefully interpreted, and limitations should be stated. Normalisation to the peak or mean EMG amplitude throughout the task investigated is recommended.

Coming Soon