Trigger shifters vs Grip shift shootout

There are three major types of shifters in the market today, and two non-standard choices. I will look at all five with respect to bicycle touring.

1. Grip shifters - These force you to rotate your hand in order to shift. There will be additional stress on the wrist, and it will most likely create discomfort eventually. I would recommend people stay away from these.

2. Trigger shifters - These are normally light action, different styles force you to use different fingers. However they all keep your wrist in a stationary position, and the light action should not adversely affect your fingers ( though that may be a problem on occasion ). These are an excellent choice.

3. STI brake lever shifters - These are normal on road and touring bikes. You can keep your hands on the hoods while shifting. There is minimal forces on the wrist during shifting, hence irritation is unlikely. These are an excellent choice.

4. Downtube shifters - This was the norm on road bikes two generations ago. Your entire hand needs to move to shift, so  the stress will be distributed among various positions, which minimizes the risk of injury. These are a good choice.

5. Thumb shifters - This was the standard shifter on mountain bikes three generations ago. The stress on the thumb is greater than all the other shifters, and these would likely cause some hand issues over time. I would recommend people to stay away from these.