Assessment of quadriceps muscle inactivation with a new electrical stimulation paradigm

: In this study we evaluated the validity of garment‐based quadriceps stimulation (GQS) for assessment of muscle inactivation in comparison with femoral nerve stimulation (FNS). Methods : Inactivation estimates (superimposed doublet torque), self‐reported discomfort, and twitch and doublet contractile properties were compared between GQS and FNS in 15 healthy subjects. Results : Superimposed doublet torque was significantly lower for GQS than for FNS at 20% and 40% maximum voluntary contraction (MVC) ( P < 0.01), but not at 60%, 80%, and 100% MVC. Discomfort scores were systematically lower for GQS than for FNS ( P < 0.05). Resting twitch and doublet peak torque were lower for GQS, and time to peak torque was shorter for GQS than for FNS ( P < 0.01). Conclusions : GQS can be used with confidence for straightforward evaluation of quadriceps muscle inactivation, whereas its validity for assessment of contractile properties remains to be determined. Muscle Nerve 51 : 117–124, 2015