A patient with a complete thoracic spinal cord injury performs seated push-ups on a mat by pressing down with both hands while attempting to lift the buttocks. This exercise primarily strengthens which muscle group?

A patient with a complete thoracic spinal cord injury performs seated push-ups on a mat by pressing down with both hands while attempting to lift the buttocks. This exercise primarily strengthens which muscle group?

• A. Quadratus lumborum
• B. Internal obliques
• C. Latissimus dorsi
• D. External obliques

Answer: (C)

When lifting the body from a seated position by pressing through both hands on a fixed surface, the latissimus dorsi is the primary muscle being used. This muscle extends and adducts the shoulder, and with the arm fixed during the push-up, it helps generate the force needed to pull the trunk upward and stabilize the shoulder girdle as the buttocks rise. In a complete thoracic spinal cord injury, trunk control is limited, so the body relies more on the shoulder–arm muscles to drive the movement, making the latissimus dorsi the best match for this task. The other muscles listed help with trunk stability or rotation in different contexts (for example, the quadratus lumborum stabilizes the pelvis, and the obliques contribute to flexion, rotation, or lateral bending), but they are not the primary drivers of a symmetrical seated push-up with the hands fixed.

When lifting the body from a seated position by pressing through both hands on a fixed surface, the latissimus dorsi is the primary muscle being used. This muscle extends and adducts the shoulder, and with the arm fixed during the push-up, it helps generate the force needed to pull the trunk upward and stabilize the shoulder girdle as the buttocks rise. In a complete thoracic spinal cord injury, trunk control is limited, so the body relies more on the shoulder–arm muscles to drive the movement, making the latissimus dorsi the best match for this task. The other muscles listed help with trunk stability or rotation in different contexts (for example, the quadratus lumborum stabilizes the pelvis, and the obliques contribute to flexion, rotation, or lateral bending), but they are not the primary drivers of a symmetrical seated push-up with the hands fixed.