I came up with this after struggling with some tendonitis. It gave me a nice snug holder for my ice pack so I could do other things while getting a little relief at the same time. It also keeps the ice pack from being in direct contact with your skin.
This could easily be adapted for legs or upper arms with the use of an arm off cut from an old long sleeve shirt instead of the tall socks I used for my forearm. AND if you really want to get DIY on this you could make your own gel pack too from a mix of 1 part rubbing alcohol and 2 parts water in a zip lock.
You will need a tall sock like this or even a sports tube sock.
Your ice pack.
Along the toe of my sock theres a seam. This is where you'll want to make the cut. You'll notice that you end up with a little section of toe space that makes a nice little cup when you put your ice pack in. If you have a tube sock that doesn't have a seam I would recommend you just make the cut about and inch or two above the toe area so you get that little cup space too.
The picture looks a little like I cut a section out of the sock but I assure you I only cut straight along the seam line.
Now that you have your opening put the sock on your arm inside out with the toe end just over your and scooting up just a bit to allow some extra toe to extend past your fingers.
Next with the sock still over your fingers take the cold pack and put it on your arm and fold your fingers over to grasp it and hold it.
Once you're holding that end in your sock covered hand you can use your other hand to pull the extra toe space you allowed back the other way so you start to envelope the ice pack in the sock.
The top of the sock should still be around your elbow by this time but we'll get to that.
Last step is to pull the top part of the sock from around your elbow towards your fingers. This wraps the ice pack up nice and neat so it doesn't fall out. Thats it! I usually just leave the ice pack in that and throw it in the freezer so its ready to go when ever I need it.
My sock was super long so I had pleny of extra legnth but really you only need a couple inches to fold over just so you're pack stays in place. You may have to try these steps a few times to get the fit just the way you like it but it's a simple way to keep ice in place with out having to buy some fancy velcro strap nonsense.