I would like some advice on my left (fretting) hand pinkie's (little finger) orientation when I'm playing three-note-per string scales at faster tempos. I find the pinkie flattens, especially the joint closest to the fingertip. I know my other fingers are stronger, and I see that they (middle and ring finger) are often perpendicular to the fretboard during such exercises. With the pinkie, it stays perpendicular when I concentrate, or play slower, but if I forget, I see it's flat again. I also find that it is harder to target the string with the pinkie when it is perpendicular; though perhaps that's less surprising.
Here is a photo showing the flattened pinkie orientation that concerns me:
Here is a photo showing my pinkie with a more perpendicular orientation:
My question is: am I correct to believe that the flattened pinkie is indeed a weakness that may become problematic at higher tempos? If so, are there any exercises which can help improve the pinkie position, or is it simply a case of slowing down the exercises and starting a fresh effort here?
I've been playing on and off for about 30 years, but have picked the guitar up again during Covid-19 lockdown.