Had a fall, cannot lift right arm above shoulder (but no pain)

1 month ago, had a fall in the shower (frontal fall, face/chest first), whole body and muscles were aching badly and some light bruising, but after a few days everything seemed fine, bruising went away, no redness/swelling/warmth on any parts of body.

Currently no pain, can still use both hands freely and well now. Only thing is, the right arm cannot be lifted above the shoulder. When trying to lift the arm above the shoulder, it just cannot go above the shoulder, as if the shoulder is "jammed", but there isn't any pain, redness, swelling or warmth at the shoulder joint.

Is this a rotator cuff tear/injury, or a frozen shoulder, or something else? I really hope surgery isn't required.