Some people with trigger finger choose to strap the affected finger or thumb to a plastic splint in order to reduce movement. This may help if you only have a mild trigger finger as restricting this movement can help to ease symptoms. If your trigger finger is particularly stiff in the morning, you may find that it helps to use a splint overnight.
However splinting is only a short term solution for mild trigger finger. It is ultimately not a successful trigger finger treatment compared to steroid injections or trigger finger surgery. Surgery is the only treatment guaranteed to relieve the pain and immobility that comes with trigger finger.