Before revision:  Furthermore, the nature of the swimmer is  found to be affected by the confinement: the swimmer can behave  as a pusher at low confinement, and becomes a puller at higher confinement , or vice versa;
After revision:  Furthermore, the nature of the swimmer is found to be affected by the confinement: the swimmer can behave , on the average over one swimming cycle, as a pusher at low confinement, and becomes a puller at higher confinement , or vice versa;