Normalization to an MVC that is matched to the task in terms of joint angle/muscle length, contraction type, and/or joint angular velocity. This method includes:

• Angle and angular velocity specific maximal dynamic/isokinetic/ isometric voluntary contraction: The peak EMG amplitude(s) from a maximal voluntary contraction with the same muscle action, joint angle, muscle length, angular velocity or rate of change of muscle length as the task of interest.
• Could require tailored MVCs for each task or muscle studied, or a maximal dynamic task to normalize specific phases/angles of the muscle(s) studied.
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• The muscles which are the most active, and thus which are more relevant for the task, will have more weight in the synergy analysis.

• 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 (their weights would be zero or close to zero).

• If the activation of a muscle varies at a low MVC% level, it is likely that it will have a small weight in the synergies. However, that does not mean it is not relevant to the task or that this muscle is controlled independently of the other muscles from this 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 EMG amplitude need to be carefully interpreted, and limitations should be stated. Normalisation to the peak or mean EMG amplitude throughout the task investigated.
• No information about relative activation level can be deduced by the weights of the muscles within each synergy.

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