Central nervous system injuries impede motor commands transmission to target muscles. Functional Electrical Stimulation (FES) bypass central motor control by directly stimulating the nerves of paralyzed muscles. Intraneural electrode for FES application have the potential to increase the selectivity and decrease the current threshold for activation compared to extraneural or surface electrodes. This study aims to identify electrical stimulus parameters that optimize the use of intraneural electrodes for neuromuscular FES.Electrical pulses were delivered using a non-commercial multi-channel stimulator, affording many options of pulse tuning compared to conventional stimulators. An intraneural electrode with active sites of graphene-based material was transversally implanted in the sciatic nerve of rats. Series of increasing intensity pulses were delivered from active sites, comparing various pulse parameters (pulse width, interphase delay, symmetry, ramp) on the recruitment and selective activation of tibialis anterior, gastrocnemius and plantar interosseus muscles.The threshold current required for neuromuscular activation was compared between a conventional protocol (100 μs pulse width, no interdelay, biphasic symmetric) and the rest of the parameters. A pulse width of 50 μs enabled neuromuscular activation at a lower threshold current. Introducing an interdelay between the cathodic and anodic phases of the electrical pulse notably reduced the activation threshold. Pulse asymmetry had slight positive effect for pulse width of 50 μs. Selectivity remained high across all tested parameters without substantial variations.These findings can help to enhance fine control of muscle activation and reduce the required charge extending battery life and conductive material integrity in chronic use of FES.