The exercise program14 comprised back extensor
strength and endurance training, accompanied
by trunk and lower extremity exercise training,
which were performed within the same sessions. It
began within a few days of the education session,
and occurred three times a week for 12 weeks. The
program was systematic and individualized, thus
accommodating participants of varying levels of
fitness and symptoms, and allowing measurable
progression of the workload over the 12-week
training period. The back extensor strength and
endurance training portion of the program was
designed to load the back extensor muscles in a
graded manner using a variable-angle Roman chair.