Abstract: Discrete-time joint acceleration bounds are widely used to enforce position and velocity limits. However, under voltage-constrained electric actuators, kinematically admissible accelerations may be physically unrealizable, exposing a missing execution-level abstraction. We propose Actuator-Aware Joint Acceleration Control (AJAC), a joint-level realizability contract that grounds kinematic acceleration bounds in voltage-constrained actuator physics by operating accelerations. Hardware experiments on electric actuators and a wheel-legged quadruped show that AJAC removes unrealizable accelerations, restores consistent near-boundary execution, and reduces boundary-induced oscillations.