Does substituent's conformation influence the kinetics of reduction reactions on trans-4-X-decal-1-ones and to what extent?

Article abstract of DOI:10.1016/S0040-4020(02)00303-4

Stereochemistry and relative rates k_ax and k_eq of reduction reactions on title compounds have been measured under five different reaction conditions (NaBH₄ in i-PrOH, LiBH₄ and NaAlH₄ in THF and LiAlH₄ in THF and in Et₂O). Experiments indicate that axial substituents behave as far less electronegative than their equatorial counterpart in reactions at the equatorial side of molecules.