This was probably meant to be 'strong and capable' (unless you meant to have each word on its own).
Strong - Physically powerful Ex. "He's so strong, he can lift 200 lb. weights!" Capable - Having the ability [capability] to do something, or to do things in general Ex. "Don't worry, ma'am. I'm capable of helping your son."
Together, 'strong and capable' is a fairly common phrase. It just means both of their individual meanings. Ex. "He's handsome, smart, strong, and capable. If only he didn't have a girlfriend!"