Numerical analysis of the extension capabilities of the M2H-HBMAs. (a, c) Geometry, boundary conditions, load identification, and (b, d) numerical analysis results for the TA and HA, respectively. The axial displacement of the (e) TA’s and (f) HA’s AACs per level. (g) Plots showing the differences in displacement between upper and lower balloons for every level in the stacked TA and (h) HA. (i) Empirical prediction of the M2H-HBMA axial extension with additional stacked levels.