Why should we maintain a tight position throughout the kip? The arch position allows you to open the shoulders and hips and store energy to provide the kip with power. The tighter we are in this position the more efficient our kip will be.
In this video, I would recommend Josh reduce the range he gets through his lumbar spine when extending his hips. I’d prefer it if he could increase the range cumulatively through his thoracic and without hinging through one particular joint. Josh may find this beneficial as it may reduce stress through the lumbar and therefore reduce his chances of injury.
We would start by really emphasising ways to squeeze his midline and especially his glutes when in the arch position. Josh may also benefit from some accessory work to his thoracic spine.