Here’s what I wrote
Ames, thanks for posting and congratulations on your Kaizen Spirit to become a more complete swimmer by practicing Backstroke.
Besides creating a more global skill set, improving Backstroke will also benefit your Freestyle, because Balance, Streamlining and Propulsion are so complementary between them.
Here’s a brief analysis of what I can see in your surface-view video:
Note: When analyzing stroke technique, always review Balance-Streamline-Propulsion in that order.
Balance (1) Your head is neutral (face parallel to surface) with ears submerged, and calm water around it. (2) Each thigh clears the surface as you roll. (3) Your kick is calm and relaxed. All indicate good balance.
Streamline Calm water around you indicates a minimum of Wave Drag. With regard to Form Drag, I see a possible improvement opportunity: Slightly increase rotation so shoulder is fully clear of the water on recovery.
You may be able to do that by turning your shoulder slightly toward your chin as you recover, rather than rolling farther with entire torso.
You can further minimize Wave Drag by swimming a bit ‘taller’ via a Focal Point of extending from entering hand to opposite foot as your hand approaches entry – similar to TI Freestyle emphasis of ‘flicking’ left toes to drive right hand toward its target.
Focus on these for several practice hours before shifting to the Propulsion focus below.
Propulsion The most challenging skill to improve in Backstroke is the way you initiate the stroke because (1) Unlike freestyle you can’t see it as you work on it, and (2) The arm position is more awkward and allows less natural leverage than in freestyle.
Essentially, you should aim for a feeling very similar to the Soft Hook position in freestyle. Is your hand is slipping back in the early part of the stroke, or do you have a sense of Holding Your Place — then using weight shift/body roll to move past it.
Try these Focal Points:
1) Sweep slightly wider, as if trying to touch lane line with fingertips.
2) Try to hold or anchor a nanosecond sooner and a millimeter closer to the surface.
3) Rotate elbow slightly overhead or outside, or open your axilla (underarm) as you catch.
This will require enormous patience both for the reasons described above (can’t see, low leverage, awkward) and because the muscle-recruitment adjustments required are subtle and complex.
For that reason I suggest the following:
1) Learn subtle adjustments first with single-arm practice. (Shown along with a complete learning sequence and all key stroke skills on Backstroke for Every Body DVD.)
2) Alternate drills with brief whole-stroke repeats – 6 to 20 strokes.
3) Use one focal point on drill, then same focal point on whole-stroke.
4) Gradually increase whole-stroke repeats. A good set for this:
4 x 25
3 x 50
2 x 75
1 x 100
Only progress to next longer distance when satisfied with sensation you maintain on shorter repeats.