Exercise guide
Lying Single Arm Slide From Y To
- Intermediate
- Compound
- Rep-based
- Back
- Shoulders
- Waist
This prone unilateral exercise isolates the posterior deltoids and scapular stabilizers, enhancing shoulder mobility and mid-back strength through a controlled sliding arc. It is highly effective for correcting postural imbalances and improving overhead mechanics by targeting the lower traps and rhomboids.
Reviewed by the Crucible Fit team · Updated June 2026
Muscles worked
Setup
- Lie face down (prone) on a smooth floor surface, extending one arm overhead at a 45-degree angle to form the 'Y' position.
- Place your non-working hand under your forehead or by your side to maintain a neutral neck and stable base.
- Engage your core and glutes to keep your hips and chest glued to the floor throughout the set.
How to do it
- Exhale as you slide your hand in a wide, controlled arc away from your midline, moving from the 'Y' position down to a 'T' position (perpendicular to your torso).
- Maintain a slow, deliberate tempo, taking approximately 3 seconds to move between positions.
- Inhale as you reverse the arc, sliding the hand back to the starting 'Y' position while keeping the shoulder blade retracted.
- Complete the full rep count on one side before switching to the other arm.
Form checklist
- Keep the sliding hand in constant contact with the floor to maintain tension.
- Ensure the shoulder blade stays depressed (pulled away from the ear) to avoid shrugging.
- Keep your torso flat; do not rotate your chest off the ground to help the arm move.
- Maintain a fully locked elbow to ensure the movement is isolated to the shoulder joint.
Pro tips
- Apply slight downward pressure into the floor as you slide to create 'self-resistance' and increase muscle fiber recruitment.
- Focus on 'pulling' the shoulder blade toward your opposite back pocket as you transition from the Y to the T position.
Make it harder
- Hover the hand one inch off the floor throughout the entire arc instead of sliding it, removing all friction support.
- Add a 3-second isometric hold at both the 'Y' and 'T' positions to increase time under tension.
Frequently asked
- What muscles does the lying single arm slide from y to work?
- The lying single arm slide from y to primarily targets the rhomboids and trapezius, and also works the abs, obliques, and serratus anterior as secondary muscles.
- What equipment do you need for the lying single arm slide from y to?
- The lying single arm slide from y to requires no equipment — just your body weight.
- Is the lying single arm slide from y to good for beginners?
- The lying single arm slide from y to is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.