Problem with my left hand

[deadlyhippo4]

 
https://www.dropbox.com/s/3yu0pr7ebm3ylm5/20170627_191631.mp4?dl=0

https://www.dropbox.com/s/dcu2bbulhmtcoe8/20170627_194256.mp4?dl=0

Hey guys, my left hand is tending a lot and I dont know how to fix this problem. My left hand is also noticeably weaker and while my right hand seems to have more dexterity then my left which always lags behind. I posted these two videos of me doing C Major and G Major scales so that you can see how I play with both hands alone and together. Please help, this problem has plagued me for many years.

[hardy_practice]

Not at 170.58 MB!  I've only got dialup.

[feddera]

Two things you do better with your right than your left:

1) Look at the angle of your wrists. In your right arm the forearm and your hand form more or less a straight line, which is good. In your left your wrist is much lower than your hands, which undermines support from your forearm and makes the fingers feel weak.

2) Your right hand plays much closer to the keys than your left hand. A good exercise for you would be to try playing very slowly, and to make sure that the fingers are already on the key surface before you play them. When playing fast the non-playing fingers should not necessarily always be in contact with the key surface, but as close as possible is usually good.

For general left hand dexterity I'm sure there are lots of pieces and exercises you could do. What helped me the most, was to just learn a few chords and scales on a guitar.

[keypeg]

As feddera says, there is a marked difference between how you use each hand.  Look at the still picture in the 2nd video before hitting "play" - there is a huge dip in the wrist.  Instead of just fixing the height of the wrist, perhaps you should look into your whole mechanism of playing scales and do a revamp at slower speeds.  Do you have a teacher, and if so, has this teacher been helpful in pointing anything out to you physically?