Help next to my lower leg? Any thinking?

My trainer told me that my lower left leg moves. My right leg does not, and to the right, neither does my left. But when I go to the moved out, my left leg is insecure at the canter. It moves around, and gooses my horse. Can you give me any excersises, on the horse or off, that I can do to help/fix this?
toes in heels down whether it hurts then you are doing it right.
Concentrate on your leg conciously focus on it and try riding Bareback walk/trot/canter and as your legs strengthen jump Bareback will make you so SOSO sore but it will also build up your leg muscles so much.

here are a few more contained by the saddle: Do all wak trot canter
drop your stirrups (put them up if they spook your horse)
put your feet contained by the stirrups backward with your heel on the stirrup iron
Put a piece of paper lower than your left leg toward you lower calf and DONT DROP IT

I do these frequently!! They work really well. :)
Answers:    It normally has to do with the way the horse moves, since one side is never equal to the other. You need to figure out if your disappeared pelvis is more active in following the horse's movement (probably is) and then focus on making your leg more independent of your hip amalgamated, which is formed by the femur of your leg attaching to the side of your pelvis. This is much less difficult to solve when you recognize where the problem originate, and focusing your solution on that point. So, assuming that it is originating in the hip joint, that is to say where you need to stabilize the movement of your leg. Exercises that strengthen the supportive structures of that joint will serve. Leg lifts, especially lateral, will help. Also incorporate towards the back and forward lifts. Just hang on to something, and slowly raise your leg, extended, out to the side to a count of 8. Hold it here for a count of 8, and then bring it back down to a count of 8. Then do it forward and backward alike way.
When you are on the horse, pay attention to your pelvic movement, and focus on separating your leg from that, and keeping it in a fixed position on the horse's side. This will train your muscles to control your leg from the hip down, so it comes first. After you hold that, you can concentrate on the rest of your leg, one section at a time.
build your muscles off the horse. It's best done at the gym. Work on hamstrings, calf, and quads.
I know this seems to obvs. but dont ride next to stuirups for like an entire week!

I had the same problem.
Actually I still do, because one of my legs are slightly longer than the other one. so you call for to put more weight and pressure on that leg and shift your upper body slightly to that side. thats what helpped me! It may seem like your throwing yourself bad balance but trust me, your just not used to the adjustment.

your actaully more square contained by the saddle.
Jumpers: Help on my form, please?   Okay so any aid would be great...?   How to ask for collected trot?   Can someone sustain me find more information on gypsy vanners?