What is a significant disadvantage of Surface EMG?

The correct choice highlights a significant limitation of Surface Electromyography (sEMG), which is its potential to capture activity from muscles that are not the primary target of measurement. This phenomenon, known as cross-talk, occurs because surface electrodes collect electrical signals from all underlying muscle fibers within their proximity. As a result, the readings may not accurately reflect the activity of the intended muscle group, leading to misinterpretation of neuromuscular function or coordination.

Understanding this disadvantage is crucial in situations where precise muscle activity is essential, such as in rehabilitation or movement analysis. Accurate data is foundational for effective treatment plans, and if the recording includes interference from nearby muscles, it can compromise the validity of the assessment.

In contrast, the other options present factors that either pertain to cost, invasiveness, or supervision, which are less intrinsic to the measurement accuracy and interpretation of the data produced by sEMG. Thus, while those aspects may influence the practicality of using sEMG in certain scenarios, they do not specifically address the technical limitations regarding recording fidelity which is captured in the correct answer.