A Scott bench with ergonomic thorax stabilisation pad improves body posture during preacher arm curl exercise

We assessed whether the use of an ergonomic thorax stabilisation pad, during the preacher arm curl exercise, could significantly reduce the excessive shoulder protraction and thoracic kyphosis induced by the standard flat pad built into the existing preacher arm curl equipment. A 3D motion capture system and inclinometers were used to measure shoulder protraction and thoracic kyphosis in 15 subjects performing preacher arm curl with a plate-loaded machine provided with the standard flat pad. The same measures were repeated after replacing the flat pad with a new ergonomic pad, specifically designed to accommodate the thorax profile and improve body posture. Pad replacement significantly (p < 0.001) reduced shoulder protraction (from 12.0 +/- 2.4 cm to 7.9 +/- 2.6 cm) and thoracic kyphosis (from 35.5 +/- 8.2 degrees to 29.6 +/- 8.5 degrees), enabling postural and functional improvements within the entire spine, shoulder girdle and rib cage. The ergonomic pad may potentially allow a more effective training, prevent musculoskeletal discomfort and reduce the risk of injury.