Tension in strumming arm?

I am a "couch player" of about 8 years.

I mostly play fingerpicking tunes. However, I've been trying to play with a pick more lately. Aside from being a little clumsy with the pick, I also have a problem with my strumming arm kind of tightening up while I play. It's like it gets all tense or something, which makes it hard to even strum through an entire song without messing up. This has always been a problem for me (but it's not as bad when I'm fingerpicking).

Does anyone have any advice as to how to solve this problem??

Maybe you are strumming too hard?

Actually I strum pretty softly. It feels like I just need to relax my arm somehow, but I just can't seem to do it. I wonder if I'm playing in a weird position or something?

You might be.

You could try different shape and thickness picks. I use tiny stiff picks and hold them very lightly.

You also should consider taking a few lessons just to make sure that you're not doing something that could become a long term habit.

This happens to me when I play one of my electrics sitting down for more than a few minutes. In the sitting position, the guitar moves to the right in relation to my body. However, all is well when I stand. I began to stand while playing several years ago when I had an LP, which would literally make me sore if I played sitting for very long, so I have been a "stander" ever since. Though it doesn't bother me when I play my acoustic.

I'd suspect your wrist is the problem. Make sure it's all loose and floppy and I'll bet the problem disappears. Make sure your shoulder is loose too.

Get some Everly Brothers songs and listen to the strum pattern on them then try to play them. This will give you some good loose strumming to do while you build confidence and muscle flexibility. It alright to play their stuff loosey goosey.

my right arm tenses up a lot too, and I have the trouble that others describe when sitting and the guitar is to the right--it hurts my shoulder after a while

when I pick too hard the sound is tense, too. And with an electric, I don't need to pick that hard for volume, so it's counterproductive

I tried moving the guitar more to the center, classical style, and just concentrating on relaxing and not picking too hard

Sounds like you are used to finger picking, where your arm stays pretty still, and now flat picking with arm movement is raising the tension problem.

Here are some thoughts that might help.

There is a wide range of technique used for various results. Strumming may flex or rotate your shoulder, upper arm, forearm, wrist, and fingers... to varying degrees.

Some rock guitarists hold their whole arm straight and stiff to strum from their shoulder (and sling their guitars down low to do this), others hold their lower arm and hand firm and move that from their upper arm so just their forearm and hand go up and down, others hold their arm pretty motionless and strum from the wrist - usually by rotating the knuckles up for upstrokes and down for down strokes (like feathering an oar). And some actually hold their whole arm and hand fairly motionless and do all the strumming movements from just moving the pick by bending and flexing the thumb and the fingers holding the pick, moving their hand just a little.

These are all pure cases; each individual will find the mixtures that are comfortable and effective for their style and purpose. The point is that you should experiment with using these techniques to find what you like. Some people naturally find their strumming techniques without thinking about it at all, others will need to experiment and discover how to match the sound and style they want to the combination of muscle groups that feels and works best.

Different guitars, and how you hold them, make some strumming easier than others. Playing a thin electric while standing is probably the easiest because the arm just touches the guitar rather than hangs over it.

If you are playing a big boxy acoustic guitar (especially if sitting), resting your strumming arm over the top of the guitar may be uncomfortable. When just laying there while finger picking it might not bother you, but when including the motion of strumming the discomfort might come on - you might be trying to lift your arm a little to relieve the downward pressure of the arm moving on the top of the guitar. I can imagine that after a while that constant lifting would cause tension...

The position of the guitar against your body makes a difference, too. Some people hold the guitar toward their right side (Johnny Cash style) to make the right arm more comfortable for picking and strumming - good for those that play lots chords; others hold the guitar out to their left side (Jeff Beck style) to make it more comfortable for the left arm - good for lead playing and executing technical passages. Try lots of variations on position, both left-right and high-low to see what feels best. Try standing and sitting. Try comparing holding the neck out level and then up at higher angles... your fingers, hands, arms, and general comfort will tell you when you are zeroing in on what will be best for you and a particular guitar.