Creating haptic interfaces capable of rendering the rich sensation needed for dexterous manipulation is crucial for the advancement of human-in-the-loop telerobotic systems (HiLTS). One limiting factor has been the absence of detailed knowledge of the effect of operator limb dynamics and haptic exploration dynamics on haptic perception. We propose to begin investigations of these effects with single-joint haptic exploration and feedback of physical and virtual environments. Here, we present our experimental apparatus, a 1-DoF rotational kinesthetic haptic device and electromyography (EMG) system, along with preliminary findings from our efforts to investigate the change in stiffness discrimination thresholds for differing exploration velocities. Result trends indicate a possible relationship between exploration velocity and discrimination thresholds, as well as a complex interaction between muscle activation, exploration velocity, and haptic feedback.