Eccentric cycling can be very effective for rehabilitation and training programs

Eccentric cycling is effective for knee extensors and hip flexors to increase muscle hypertrophy and strenght. Possible great outcomes for rehabilitation and training purposes. 
www.sciencedirect.com/science/article/pii/S0268003309002538?fbclid=IwAR1a_6nPaeByXEN0rVjKfEj1CLtMyic0qtNCtG57GiAfH1TMQm4QnMXgiYs#fig1

Eccentric cycling: a motor move pedals toward the cyclist, who is resisting. Motor force exceed cyclist resistance, this allow eccentric muscle work.