WARNING
Discussing the alignment of the yellow & red lines -
There is a recommendation by Todd Ellenbecker to limit the angle of the upper arm to the shoulder. He warns in a video "Rotator Cuff Injury". That video is available on Tennis Resources. Get the shortest membership to view the videos.
All or almost all ATP players appear to follow Ellenbecker's recommendation on the angle of the upper arm & shoulder.
Your arm in the picture is too high for a high level serve using Internal Shoulder Rotation (ISR). Post your videos using Youtube, it can single frame, no sign up.....
Forum Search: Internal Shoulder Rotation Ellenbecker Rotator Cuff Injury
Member: Chas Tennis
I have posted on this subject many times with pictures and videos.
You might have the idea that 'I should reach as high as possible' That is totally wrong for a high level serve - pictures show many angles at impact, not reaching straight up. Look at a picture and observe all the angles. Google:
tennis serve ATP pictures __Look at all the angles, including in side camera views. Always remember angles are in 3D but images show only 2D.
The only studied serve technique is the
high level serve with ISR as used in the ATP
. But most active tennis players do not use the high level serve, the majority use a 'Waiter's Tray' technique. Lots of posts on that too.
All other technique are DIY and suspect. [DIY - do-it-yourself]
Welcome to the
Tennis Serve Nuthouse.