Validity and Reliability of Surface Electromyography Features in Lower Extremity Muscle Contraction in Healthy and Spinal Cord–Injured Participants

This study looks at how well certain measurements from muscles in the legs correlate with actual muscle force, and how consistent these measurements are over time. The goal is to see if these measurements can be used to track muscle function in people with spinal cord injuries (SCI). The study compared these muscle measurements in healthy individuals and those with SCI to see if they could be reliable indicators of muscle effort, even when muscle control is affected by SCI.

• 1
  In healthy participants, SEMG features correlated well with torque (TA: ρ > 0.92; SOL: ρ > 0.94) and showed high reliability (ICCmean = 0.90; range, 0.72-0.99).
• 2
  In an SCI case series, SEMG features also correlated well with torque (TA: ρ > 0.86; SOL: ρ > 0.86), and time-domain features appeared no less repeatable than amplitude-based measures.
• 3
  Time-domain SEMG features are valid and reliable measures of lower extremity muscle activity in healthy participants and may be valid measures of sublesional muscle activity following SCI.