Hi Andrea! Hammer curls call a bit more on your brachioradialis muscle than traditional curls do. This is the muscle that is used very much in everyday life when you pick things up while your arms are in the hammer curl position. I actually make mention of this in the slow and heavy series biceps routine.
Yes, you will definitely make strength gains with hammer and overhand grips.
If you currently have pain in your left wrist, stop doing any exercise that aggrivates it, let it rest and then take anti-inflammatory medication for a couple of days. Then when you return to your regular curls, lighten your weight by about 50 percent while you do them. If you feel pain again, stop the exercise and focus on the other grips. While doing the other grips, include forearm exercises to strengthen your forearms (reverse curls and regular wrist curls. We have these exercises featured in the slow and heavy bicep workout too). This will help reduce the stress on your wrist by strengthening the surrounding muscles. After two or three weeks, again introduce the regular curls with very light weight. They should feel much stronger now. If not, I would play it safe and have your wrist checked out by your doctor. Good Luck!
