  We compute spin-orbit torques (SOTs) in strained PtMnSb from first
principles. We consider both tetragonal strain and shear strain. We find a
strong linear dependence of the field-like SOTs on these strains, while the
antidamping SOT is only moderately sensitive to shear strain and even
insensitive to tetragonal strain. We also study the dependence of the SOT on
the magnetization direction. In order to obtain analytical expressions suitable
for fitting our numerical \textit{ab-initio} results we derive a general
expansion of the SOT in terms of all response tensors that are allowed by
crystal symmetry. Our expansion includes also higher-order terms beyond the
usually considered lowest order. We find that the dependence on the strain is
much smaller for the higher-order terms than for the lowest order terms. In
order to judge the sensitivity of the SOT on the exchange correlation potential
we compute the SOT in both GGA and LDA. We find that the higher-order terms
depend significantly on the exchange-correlation potential, while the lowest
order terms are insensitive to it. Since the higher-order terms are small in
comparison to the lowest order terms the total SOT is insensitive to the
exchange correlation potential in strained PtMnSb.
