The ornamental design for an orthosis, as shown and described.
FIG. 1 is a front elevation view of an orthosis, showing my new design; and,
FIG. 2 is an enlarged front elevation view thereof taken from area “2” shown in FIG. 1.
Rear side elevation views of the orthosis are omitted because they are plain and unornamental and form no part of the subject matter of the claimed design.
The portions of the orthosis shown in broken lines in FIGS. 1 and 2 form no part of the claimed design.
The dashed-dotted line showings of FIGS. 1 and 2 illustrate boundaries between the claimed design and unclaimed portions.