Complex sentence: This is because the first metatarsal head would normally bear the majority of a person's body weight during the propulsive phases of gait, but these forces are transferred to the second (smaller) metatarsal head because of its anterior positioning.
Split into simpler sentences: This is because the first metatarsal head normally bears the majority of a person's body weight during the propulsive phases of gait. However, these forces are transferred to the second (smaller) metatarsal head because of its anterior positioning.