This chapter covers: Some common terminology used from now on and the utilization of open Vs close kinetic chain in the exercise prescription during ACL rehabilitation. Approaches which could be used to develop strength (maximal force) in the key muscle groups and how to programme them. The importance of also improving rate of force development and approaches to developing improved rate of force development. Science and prescription principles behind blood flow restriction and isoinertial training in ACL rehabilitation. How to reliably test force with hand-held dynamometers, isokinetic machine, and force plates eventually interpreting the outcomes comparing them with normative values. The key measureable objectives for force based training and the expected minimal standards for optimising outcome.