Medial heel wedge in balance training improves stability and function in chronic ankle instability

Chronic ankle instability (CAI) impairs balance and increases reinjury risk. This randomized trial assessed whether adding medial heel wedges to a 4-week progressive balance program produced greater gains than balance training alone. Twenty-two participants with CAI were randomly assigned to train with or without medial heel wedges. Postural control was assessed during various standing tasks on different surfaces with eyes open and closed. Functional performance was measured using the modified star excursion balance test (mSEBT), the single-leg hop test (SLH) (with subsequent calculation of the limb symmetry index, LSI), and the single-leg squat. Both groups improved on most balance and functional measures. The intervention group showed greater gains in static postural control-especially single-leg stance on a soft surface with eyes open (p < 0.05)-and in mSEBT anterior reach (p = 0.004; η²=0.186). LSI, SLH, and single-leg squat improved within both groups with no between-group difference (p > 0.05). Progressive balance training is highly effective at improving balance and function in CAI, while the addition of medial heel wedges provides a selective, additional benefit for dynamic forward reach and static stability under demanding conditions. Because post-tests were performed without wedges, the between-group differences are consistent with neuromuscular adaptation, although the influence of mechanical carryover or learning effects cannot be entirely excluded. Heel wedges may be a simple adjunct in CAI rehabilitation and may potentially contribute to reduced reinjury risk; this requires prospective follow-up.