Balancing Leg Workouts

[BrknFngrs]

I hurt my left knee a while back so I was favouring my left leg quite heavily. I no longer have pain in my left knee but I think that I must still favour my left leg because it is noticeably smaller then my right and my right is generally more sore after a workout. I've been using a mirror when I squat and deadlift and as far as I can tell my hips are facing straight forward and I'm dropping down even between both knees on my squats.

I also include single leg exercises in all of my leg workouts (split squats, lunges, etc)

Can anyone recommend a way to better balance my leg development or to identify where I am favouring my left leg so heavily?