It is not all about Quads in ACL rehabilitation
There is an emphasis on quadriceps strengthening during ACL rehab but do not neglect your hamstrings "contraction of the hamstrings contributes to knee stability".
At 6 months post ACL surgery 67% of people with Patellar tendon graft had >90% hamstring symmetry achieved, only 46% with Hamstring Tendon Graft.
In the early stages of the rehabilitation prone leg curl, standing leg curl and bridge is suitable.
Then the later stages can introduce Nordics and Razor Curls to target eccentric strength and can be combined with RDL's .
Once you have this strength base achieved and your chartered physiotherapists has given you the green light Sprinting is next to strengthen the hamstrings in the End Stage of ACL rehab.
This is maximal velocity sprinting for every 10m you sprint 1 minute break is required.