The Hebrew noun atstsil (H679) refers to a joint or hinge — specifically used for the side or armhole area of a garment or the shoulder joint of a body. It appears in contexts describing structural joining points, whether of the body or of priestly vestments.
The anatomy of the human body and the construction of sacred garments are both treated with precision in the Hebrew Bible, reflecting God's intentional design. The atstsil or joint speaks to the interconnection of parts — a fitting symbol of the Body of Christ, where each member is joined together (Ephesians 4:16). The shoulder joint bears the weight; Christ's shoulders bear the government and our burden.