Prone Y's
A prone shoulder stability exercise that isolates the lower trapezius and posterior deltoids to improve posture and overhead mechanics. By lifting the arms in a Y-shape while lying face down, it strengthens the mid-back and combats rounded shoulders.
Iridium utilizes sub-muscle-group fatigue awareness to schedule Prone Y's, ensuring the lower trapezius receives direct volume even if your lats are already tapped out from heavy rowing. Because this exercise generates minimal systemic fatigue, the AI often assigns it to help you hit Minimum Effective Volume landmarks without negatively impacting your recovery score for the next session.
Form Cues
- Lie face down with arms extended at a 45-degree angle
- Point your thumbs up toward the ceiling
- Slide your shoulder blades down toward your back pockets
- Lift your arms by squeezing your mid-back muscles
- Keep your chin tucked and neck neutral
- Don't shrug your shoulders up toward your ears
- Don't arch your lower back to lift higher
- Don't bend your elbows to compensate for weakness
- Don't lift your head and look forward
- Don't use momentum to swing the arms up
Common Mistakes
- Initiating with the upper traps
- Hyperextending the lumbar spine
- Bending the elbows
- Lifting the chest off the floor
- Craning the neck upward
Muscles Worked
This exercise specifically targets the lower fibers of the trapezius and the posterior deltoids, which are crucial for scapular depression and upward rotation. By stabilizing the shoulder blade, it also engages the middle trapezius and recruits the erector spinae isometrically to maintain a neutral spinal position.
Primary
Secondary
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