Source: Tafsir al-Ahlam al-Kabir (Ibn Sirin)
The back in a dream is a man's support and help from a brother, son, or friend. Its strength is the support's strength, and its breaking is the death of whomever it represents.
Source: Ta'tir al-Anam fi Ta'bir al-Manam (Al-Nabulsi)
The back indicates religion. Whoever sees himself carrying a heavy load on his back is carrying many sins.
Source: Al-Isharat fi Ilm al-Ibarat (Ibn Shahin)
The back is interpreted as prestige and position. Whoever sees his back hunched, his prestige is gone.