Which sentence is punctuated correctly?
Don wore braces on both of his legs still; he was an avid runner.
Don wore braces on both of his legs: still he was an avid runner.
Don wore braces on both of his legs still, he was an avid runner.
Don wore braces on both of his legs; still, he was an avid runner.
Don wore braces on both of his legs still; he was an avid runner.
Don wore braces on both of his legs: still he was an avid runner.
Don wore braces on both of his legs still, he was an avid runner.
Don wore braces on both of his legs; still, he was an avid runner.