This matrix summarizes recommendations on the use of EMG to estimate muscle force. The matrix encompasses the use of bipolar surface EMG, high density surface EMG, and intra-muscular EMG (1) to identify the onset of muscle force during isometric contractions, (2) to identify the offset of muscle force during isometric contractions, (3) to identify force fluctuations during isometric contractions, (4) to estimate force during dynamic contractions, and (5) in combination with musculoskeletal models to estimate force during dynamic contractions. For each application, recommendations on the appropriateness of using EMG to estimate force and justification for each recommendation are provided.
Challenges: Estimating muscle force from EMG is limited by signal complexity, inter-individual variability, electrode placement, and muscle fatigue. These factors can influence the reliability and accuracy of the derived force estimations.
Caution: EMG signals should not be interpreted as direct surrogates of muscle force without appropriate normalization, modeling, or calibration procedures. Overinterpretation can lead to misleading conclusions regarding muscle contribution or load.