Effectiveness of the scapular depression strategy to activate the lower trapezius during prone Y exercise

Background The lower trapezius (LT) involves scapular depression and retraction so, the scapular depression strategy is expected to increase the LT activity during prone Y exercise. Objective To investigate the effects of three different strategies during prone Y exercise on the scapular muscle activities, muscle activity ratios, and scapular positions in participants with scapular dyskinesis (SD). Method: Twenty male participants with SD participated, upper trapezius (UT), middle trapezius (MT), and LT activities were evaluated using the surface electromyography during prone Y exercise in three different conditions: 1) arm lifting, 2) intended scapular depression with arm lifting, and 3) scapular depression with roller-assist. In addition, upper horizontal distance (UHD) and scapular depression angle (SDA) were measured to identify the changes in scapular positions simultaneously during prone Y exercise in three different conditions. Results Our results revealed that the intended scapular depression with arm lifting condition demonstrated the highest LT and MT activity along with changes in scapular positions (UHD and SDA) and exhibited significantly higher than the scapular depression with roller-assist condition (P < 0.05). Whereas, UT activity showed less in the intended scapular depression with arm lifting condition compared to the arm lifting condition ( P < 0.05). Additionally, the UT/LT and UT/MT ratios were less in the intended scapular depression with arm lifting and scapular depression with roller-assist than in the arm lifting condition ( P < 0.05). Conclusions Our results indicate the intended scapular depression with arm lifting strategy is expected to be more effective in improving LT and MT activity through the adduction and depression of the scapula in males with SD particularly.