The goal of this study was to identify parameters of balance recovery that may be sensitive to postural instability early in the progression of Parkinson’s disease. The response to a backwards pull was analyzed in a group of healthy controls and a group of adults diagnosed with mild Parkinson’s disease. Video, motion, EMG, and force plate data were collected and analyzed. The effect of Parkinson’s disease on strategy (single or multiple step response, number of steps, step foot), temporal (reaction time, weight shift time, step duration), kinematic (step length, step height, ankle angle), kinetic (peak ankle torque, peak landing force) and center of pressure (location at liftoff and landing) parameters were examined for the first step in the response. In the PD group, subjects were less consistent in their choice of stepping limb over multiple trials, but did not take more steps or use a multiple step strategy more frequently than the controls. The PD group had a longer weight shift time, but had similar reaction times and step duration times compared to HC. The PD group showed different motion at the ankle joint prior to liftoff and were in dorsiflexion at liftoff whereas the HC were in plantarflexion. HC and PD showed similar ankle motion after liftoff. There were no differences in peak torques or peak landing force between the two groups;​ however the center of pressure was further posterior at landing in the PD group. These results suggest that further investigation focused on the movement preparation stage may be able to identify early markers of postural instability. Further study is also necessary to determine the relationship between these parameters and clinically defined postural instability.