- For the Simple Sword you need 7 Strength.
- For the Leather Jerkin you need 6 Strength.
For melee weapons and armour, the difficulty displayed in the item's stats is Strength. For bows, it is Power Draw, and, for throwing weapons, it is Power Throw.
By the way, if you are not going to use throwing weapons, don't spend any points in Power Throw; spend them in Power Draw (if you want to be an archer), and Power Strike (for melee damage).