Both of the things you guys brought up have been on my mind lately:
- Elbow slightly bent at contact. Yes my elbow is slightly bent at contact and then straightens fully right after the hit. When I try to straighten before contact (like Thiem) it feels terrible, like I've lost all power and the ability to make micro-adjustments to the ball position. Maybe this is all related to contact point. If I get my contact point slightly farther away then my arm would be straight then yea?
- Upper body rotation and keeping the left hand back. I feel like driving upper body rotation off the front foot is helping me a lot with generating power. If I keep my left arm back then I'm no longer turning, so where does the power come from? Obviously this works for many pros so there's something I'm not understanding here.
Things that aren't working include low balls, high balls, and deep balls (where I'm rushed). I don't know if this is related to the above things or if it's just because I'm still new to all this.
If you initially accelerate using shoulder muscles and a straight arm it takes more force to accelerate. Your shoulder muscles - positioned with very weak leverage - are not strong enough. Maybe some can do that. Federer. ?
An alternate way to accelerate is to use the stronger torque trunk and leg muscles to turn your uppermost body at the shoulders. That can accelerate the arm with the elbow straight.
Two options for initial acceleration:
1) shoulder muscles initially accelerate - Video shows upper arm separates from the chest and can move independently. F. Lopez drive technique observed in about 2013, now? Federer mostly, maybe not always. ?
2) uppermost body initially accelerates - Video shows the upper arm becomes pressed by the chest or stays pressed on the chest and the stronger trunk and leg muscles initially accelerate the uppermost body, arm and racket together. Video shows also that the uppermost body and the upper arm move together. Straight arm is used for more speed. Gasquet, Wawrinka, Justine Henin drive technique.
Understand where the rotation axis is from videos.
Note - I believe that the maximum torque that the shoulder muscles can produce limits the torque that the uppermost body can apply
= don't initially use the shoulder muscles.
Seeing a small space at the armpit requires high quality high speed video. Your video has blur and the contrast of your black shirt makes seeing a space impossible. I also can't tell if your upper arm and uppermost body are moving together. Use bright sunlight, focus carefully, close up view, better contrasts.
This long thread discusses this issue. Minimum read - post #1, then #51. Then look at the remaining videos with discussions.
https://tt.tennis-warehouse.com/ind...and-waht-force-to-start-forward-swing.462997/
Warning. Using the uppermost body to accelerate the arm and racket can increase pace. The ball striking has to be good to avoid stresses that are associated with the one hand backhand and tennis elbow.