Y’s, T’s, and I’s are excellent exercises to address common shoulder muscle function deficits.
Prone Y’s (prone full can in scapular plane) are utilized to primarily target the lower trapezius. The lower traps play a huge role in arm elevation due to its function of scapula upward rotation – however, it commonly doesn’t function optimally. “The inferomedial-directed fibers of the lower trap may also contribute to the posterior tilt and external rotation of the scapulae during arm elevation, which decreases subacromial impingement risk” (Reinold, Escamilla, & Wilk, 2009). The prone Y is also important because of its high lower trap-to-upper trap ratio. Poor muscle balance between the upper trap and lower trap is often a culprit for shoulder issues.
Similar to prone Y’s, prone T’s with external rotation (thumbs facing out and moving towards the ceiling) show an increase in lower trap-to-upper trap activity during EMG studies while also requiring continuous posterior rotator cuff activation.
Perform 3 sets of 12-15 repetitions for each movement prior to your upper body training. Begin with no weight, really focusing on correct form. Add light weights as you progress.
➡Reinold, M. M., Escamilla, R. F., & Wilk, K. E. (2009). Current concepts in the scientific and clinical rationale behind exercises for glenohumeral and scapulothoracic musculature. J Orthop Sports Phys Ther, 39(2), 105-117. doi: 10.2519/jospt.2009.2835