A loose front step rail calls for a repair, a replacement, or a warning, and the fastest way to make it worse is to tighten the wrong part. Sort the job before anyone puts their weight on it, and let Dad watch you do it, since the rail is his.
Local option: New Plan Care gives families in the St. Louis area in-home help so a parent can stay home: companionship, help with bathing and dressing, meals, and overnight care. Call (314) 405-0887.
Run the pull test first
Stand to the side, with someone close by, and push and pull on the rail at each post and at each joint where the rail meets the post. Use firm, steady pressure from more than one direction. Look at the base of each post where it meets the step or the ground. Note anything that moves, cracks, shows soft or dark wood, or pulls away from the wall or concrete. Write each finding on a sheet with a photo.
What you can often do yourself
Visible bolts or screws that have backed out can usually be snugged. Screws that have stripped or rusted can be replaced with corrosion-resistant screws of the same size and length, and you should not force a larger screw into a hole that is already oversized. Cleaning the rail so a hand can grip it is also a reasonable job. These are reversible, low-stakes steps, and they are the kind of work the family can handle.
What goes to a contractor
A post that moves at its base, a post set in concrete or a footing that has shifted, rot in a post or in the step framing, an anchor that has pulled out of masonry, or any plan to move or extend the rail all change how the structure carries load. Those are not tightening jobs. Bring the photos and the pull-test notes to a contractor and ask them to mark each item as tighten now or replace or reset.
What to ask before you agree
Ask what is included and what is extra, who pulls any permit the city requires, whether the work includes checking the footing and anchors, and whether the repair is warrantied in writing. Ask the contractor to put the scope in the same document as the price so the two cannot drift apart. For city permit rules, ask the building department directly, since requirements differ by location.
Next move: Complete the pull test this weekend, photograph every post base and joint, and ask a contractor to split your list into the items you can tighten and the items they must reset. For local referrals, see Local Help in St. Louis.