Fig. 7From: Improving postural stability among people with lower-limb amputations by tactile sensory substitutionThe head movement range in the AP direction plotted as a function of stimulus amplitude and frequency. The conditions with and without sensory substitution (SS) are shown in separate lines. The control group and the amputation group are shown in the left and right panels, respectively. Note the head movement range is unitless as it is normalized by dividing the participant's body heightBack to article page