fig4

Figure 4. The work of a single muscle. (A and B) Relationship between the measured capacitive deformation and muscle contraction displacement. The change of C_s is consistent with the variation in muscle contraction displacement with the linear regression of R² = 0.96; (C and D) Relationship between the muscle contraction force and RMS of EMG. The RMS of EMG matches the variation of muscle contraction force with the linear regression of R² = 0.91; (E) Comparison of muscle work E_w, mechanical energy E_m of the weight, and muscle oxygenation SmO₂; (F) Linear regression between E_m and E_w with R² = 0.95; (G) Characterization of the measured C_s and EMG during multiple cycles of weight lifting with one single muscle; (H) Validation of muscle work during repeated weight lifting with one single muscle. The high-pass filtered E_w is consistent with Ew_mith the linear regression of R² = 0.95. RMS: Root mean square; EMG: electromyography.