There are times when technique training won’t bear fruit.
Control of the pelvic girdle for efficient kick technique is a common region for inefficiency due to tightness, weakness, or a motor patterning issue around the pelvis.
It is worth noting that a persons walking gait pattern and work environment may be maintaining what looks to be an intractable issue. A common presentation is someone with super tight calves. This doesn’t affect their swimming directly, but during the day, the tight calves send the signal to the gluteal muscles they aren’t needed to extend the hip. From there they don’t work in the pool.
Or the desk worker using a forward head posture all day. In the pool this means to keep the head out of the water, the legs need to drop under the water, ruining the hip action and creating significant drag in the water.
Osteopathic treatment can sometimes very quickly decrease these factors by creating a more streamlined posture.
Othertimes some simple initiation exercises after a work-day or before the pool session unlocks access to that technique you consciously know about, but aren’t using.
Possibly the most common example of this is the dedicated, technique aware swimmer with rotator-cuff troubles they can’t shake. Chronic upper thoracic extension restriction and neck muscle shortening in many cases cannot be stretched out in a few minutes. Treatment and sports specific exercises can make faster progress.
There are sports specific swimmer range of motion measurements and tests that establish the presence of absolute movement restrictions likely to lead to injury and loss of performance, and I have these in clinic for just these occasions.