Support strength progressions develop the ability to support your bodyweight with just the upper body. These movements are for straight arm strength development, and should (with some exception) be performed with a locked elbow. Keeping the elbow locked puts the majority of the challenge on the scapula. Training straight arm strength should complement bent arm strength (pulling/pressing) work.
Some progressions have a prerequisite mobility to perform.
Progressions - OVerhead Support
Progression 1 - Box Shoulder Stretch
Progression 2 - Partial Wall Facing HS
Progression 3 - Wall Facing Handstand
Progression 4 - Wall Climbs
Progressions - bottom Support
Progression 1 - Foot Assisted Box Support
Progression 2 - Box Support
Progression 3 - Scap Dips
Progression 4 - Tuck Knee Raises
Progression 5 - Tuck Hanging Knee Raises
Progression 6 - Tuck L-Hang
Progression 7 - Tuck L-Sit
Progression 8 - 1/2 Tuck L-Hang
Progression 9 - Tuck L-Sit
Progression 10 - L-Hang
Progression 11 - L-Sit
Progressions- PlanK
Progression 1 - Incline Plank
Progression 2 - Plank
Progression 3 - Scap Pushup
Progression 5 - Plank Shoulder Taps
Progression 4 - One Arm Plank