Single measurement reliability and reproducibility of volitional and magnetically-evoked indices of neuromuscular performance in adults

This study documents intra-session and inter-day reproducibility (coefficient of variation V%]) and single measurement reliability (intra-class correlations R_I]; standard error of a single measurement SEM%] 95% confidence limits]) of indices of neuromuscular performance elicited during peripheral nerve magnetic stimulation. Twelve adults (five men and seven women) completed 3 assessment sessions on 3 days, during which multiple assessments of knee flexor volitional and magnetically-evoked indices of electromechanical delay (EMD_V; EMD_E), rate of force development (RFD_V; RFD_E), peak force (PF_V; P_TF_E), and compound muscle action potential latency (LAT_E) and amplitude (AMP_E) were obtained. Results showed that magnetically-evoked indices of neuromuscular performance offered statistically equivalent levels of measurement reproducibility (V%: 4.3–31.2%) and reliability (R_I: 0.98–0.51) compared to volitional indices (V%: 3.7–25.2%; R_I: 0.98–0.64), which support the efficacy of both approaches to assessment and the indices PF_V, EMD_V, EMD_E and LAT_E offer the greatest practical utility for assessing neuromuscular performance.