The ABENCH: (now owned by Precor) has the capability to add heavy
resistance such as 30 pounds on a post lever that is positioned beyond
the head. Often people have smooth concentric action during flexion of
the abdominal muscles and trunk, but do not have smooth eccentric action
during the return to the starting position. The smooth/unsmooth reps
happen for the entire set.
Extra care to carry smooth eccentric action corrects the jerkiness,
which can be helped with greater awareness of breath control in
coordination with both concentric and eccentric action.
It is possible that the ability to perform both actions smoothly would
help with greater core stability in activities of daily living and