# Lying Single Arm Slide From Y To T - Canonical: https://fitwill.app/exercise/10742/lying-single-arm-slide-from-y-to-t/ - Media ID: 10742 - Primary muscle: Shoulders - Body part: Shoulders - Equipment: Towel - Video: https://fitwill.app/videos/10742/lying-single-arm-slide-from-y-to-t.mp4 ## Description The Lying Single Arm Slide From Y To T is a prone shoulder and upper back exercise performed face down on the floor with one arm reaching overhead in a Y position on a sliding surface such as a towel or gliding disc. From there, you slide the arm in a wide arc down to a T position beside your body, keeping it straight and light on the floor the whole way. Because the hand stays in contact with the ground, the movement emphasizes controlled scapular motion rather than heavy resistance. This drill is especially useful for anyone who spends long hours sitting, since rounded shoulders and a stiff upper back often go hand in hand with weak lower and middle trapezius function. It is also a common rehab and warm-up choice for overhead athletes and lifters who need better shoulder blade control before pressing or pulling. The sliding version adds a constant, smooth tension that is hard to replicate with free weights at light loads. The main work comes from the rear deltoid, middle and lower trapezius, and rhomboids, which draw the shoulder blade down and toward the spine as the arm travels from overhead to the side. The rotator cuff muscles stabilize the shoulder joint throughout the arc, while the muscles of the chest and lats on the working side lengthen as the arm sweeps down. Your trunk stays quietly engaged to keep your ribs and hips square to the floor. Setup matters more than it looks. Lying face down with your forehead supported and your body in a straight line puts your spine in a neutral position, which prevents you from cheating by arching your lower back or cranking your neck. The arm must stay straight and slide rather than lift and swing, so the surface you slide on should be smooth enough to allow a friction-free arc without the hand catching. To execute it well, move slowly enough that you can feel the shoulder blade traveling with the arm. The end position has the thumb pointing up or the palm facing the ceiling at roughly shoulder height out to the side, with the chest still facing the floor. If your torso starts rolling open to finish the arc, the range has gone beyond what your upper back is controlling that day. Use this movement as a warm-up before upper body training, as a low-load accessory on back or shoulder days, or as a standalone drill for desk-bound days when your shoulders feel glued forward. Two to three sets of five to ten slow slides per side is plenty, because the point is quality of motion, not fatigue. ## Instructions 1. Lie face down on the floor with your legs straight behind you and your forehead resting on the floor or on a folded towel so your neck stays neutral. 2. Extend one arm straight overhead so your body and arm form a Y shape, and place your hand palm down on a small towel or gliding disc. 3. Set your non-working arm out to the side or tucked alongside your body, and brace your trunk lightly so your ribs and hips stay flat against the floor. 4. Inhale, then begin sliding the working hand in a wide arc away from your head, keeping the elbow straight and the hand in light contact with the floor. 5. Continue the arc until your arm is out to the side at roughly shoulder height, forming a T shape, with your thumb turning toward the ceiling as you arrive. 6. Pause briefly in the T position and feel your shoulder blade pull down and toward your spine without shrugging up toward your ear. 7. Exhale and slide the hand slowly back along the same arc to the overhead Y position, resisting the pull of the stretch as you return. 8. Complete all reps on one side, or alternate arms if that feels more comfortable on your neck. 9. Reset your body line between reps: check that your chest stays down, your low back stays relaxed, and your head does not lift to watch the hand. ## Tips & Tricks - The most common cheat is lifting the chest and rolling the torso open as the arm approaches the T position; keep the opposite shoulder and both hips pressed toward the floor to stay honest. - If your hand snags or the towel bunches up mid-arc, the slide surface is too grippy; switch to a smoother towel or use the disc on a harder floor. - Keep the arm straight the entire time. Bending the elbow shortens the lever and turns a shoulder blade exercise into an easy arm sweep. - Do not force the end range. If your shoulder pinches as the arm comes down to the T, stop the arc slightly higher and widen the movement over weeks instead of forcing depth. - Think of the hand following a rail on the floor rather than lifting off and re-placing; if you hear or feel the towel skipping, slow down. - A small shrug toward the ear at the top of the arc means the upper traps are taking over; consciously reach long through the fingertips instead of hiking the shoulder. - Because you are face down, it is tempting to press the forehead hard into the floor and create neck tension; let the head rest heavy and keep your gaze at the floor. - Keep the slide slow in both directions. Most of the benefit in this drill comes from the controlled return to the Y position, not the slide out. - If one side feels noticeably tighter or weaker, start with that side and match the rep quality, not the rep count, on the other side. ## Frequently Asked Questions ### What muscles does the Lying Single Arm Slide From Y To T work? It primarily trains the rear deltoid along with the middle and lower trapezius and rhomboids, which control the shoulder blade as the arm travels from the Y to the T position. The rotator cuff works to keep the shoulder joint stable throughout the arc. ### Can I do the Lying Single Arm Slide From Y To T without a gliding disc? Yes. A small towel on a smooth floor works well, and on carpet or a mat you can simply slide the back of your hand directly if the friction is low enough. The key is that the hand glides rather than grips. ### Why is this exercise done lying face down instead of standing? Lying prone removes momentum and gravity-assisted cheating, forces the shoulder blades to do the work, and keeps the spine neutral. It also puts the shoulder in a safe position for training the arc from overhead to the side. ### Is the Lying Single Arm Slide From Y To T suitable for beginners? Yes, it is a low-load movement, but beginners often rush it or roll the torso open. Start with a shorter arc, five slow reps per side, and only extend to the full T position once you can keep your chest facing the floor. ### Should my hand stay on the floor the entire time? Yes, light contact throughout the slide is what makes this a controlled scapular exercise. If the hand lifts, the shoulder is typically compensating or the range has exceeded your current mobility. ### My lower back arches when I slide my arm down. How do I fix that? That usually means the chest is lifting to buy range. Brace your trunk gently, imagine pressing your hip bones into the floor, and reduce the arc until you can move without the low back taking over. ### Can I use the Lying Single Arm Slide From Y To T as a warm-up before pressing or pulling? Absolutely. It is a good primer before overhead presses, bench work, or pull-ups because it wakes up the lower traps and rear shoulders without fatiguing them. One or two easy sets is enough. ### How does the single-arm version differ from doing both arms at once? The single-arm version lets you focus on one side, makes imbalances obvious, and frees the other arm to help you monitor whether your torso is staying square. It is usually the better place to start. ### Is it normal to feel this more in the shoulder blade than the arm? Yes, that is the intended sensation. The arm is just the lever; the muscles pulling the shoulder blade down and inward toward the spine should be doing most of the work. ### When should I avoid this exercise? Skip it if lying prone is uncomfortable, if the arc causes shoulder pinching that does not ease with a shorter range, or if you have an acute shoulder injury and have not cleared floor-based arm movement with a professional.