  Context: It is generally presumed that the outflows from a YSO are directed
close to its rotation axis (i.e. along its angular momentum vector and
orthogonal to any attendant accretion disc). Many YSOs are formed from dense
prestellar cores embedded in filaments, and therefore the relative orientations
of outflows and filaments may place useful constraints on the dynamics of core
formation.
  Aims: We explore this possibility, from the viewpoint of what it may tell us
about the angular momentum delivered to a core forming in a filament. We stress
that we are not here addressing the issue of the relationship of filaments and
outflows to the prevailing magnetic field direction, although this is evidently
also an interesting issue.
  Results: Using the limited data available, and neglecting any possible
selection effects or correlations between nearby outflows, we infer that the
observed outflows have a tendency to be orthogonal to the filaments that
contain their driving sources. Specfically, in the cases where the directions
of the filaments and outflows are well defined, we infer statistically that 72%
of outflows are within $45^{\rm o}$ of being orthogonal to the filament, and
only 28% are within $45^{\rm o}$ of being parallel to the filament.
  Conclusions: This suggests that the prestellar cores which spawned the YSOs
driving the observed outflows had angular momenta which were approximately
orthogonal to the filaments out of which the cores formed. We briefly discuss
the implications of this for two proposed core formation mechanisms.
