This is related with shoulder blade story. Something useful to relax your shoulder muscle was introduced in blog written by OD BOX ANNEX in Okachimachi. I went there to check it out for real.
Nordic skiing is good for raising shoulders' flexibility. This hand is...
店長の面川（おもかわ）さんです。「こんにちは！」
Store manager Omokawa-san. "Hi there!"
使い方は普通に歩く動作にポールを持つだけ。肘を常に伸ばすのがコツだそうです。
How to use: Grab them while you walk. That's it. Just make sure to straight your arm throughout walking.
実際使っている図ですが、ワタクシ、どうも右手と右足が同時に出てしまい… どうも微妙なので割愛です（苦笑）。
Well, I can't really show a picture which I'm using them. My right arm and right foot move at the same time, which is really awkward...
かわりに細部をご紹介。グリップの赤いボタンを押すと…
In stead, I'll show details: when you push a red bottom at grip,
カチッとこのように簡単に外れます。給水時などに便利ですね。今までのタイプはいちいちベルトを手から外さないといけなかったそうです。
A hand strap will be come off easily. It's useful when you hold a water bottle. You had to take off straps each time you'd like to use your hand with previous types.
先の滑り止めはこんな感じ。
A spike pad.
進む時にぐっとこれで地面を押し、その勢いで腕がまた前に振れる。結果、肩まわりの大きな運動になり、実際のジョギング時に腕がよく振れる基本がつくられるというわけ。
You use this spike to make yourself move forward. That power makes your arm to swing forward more. As a result, you use muscle well around your shoulder and that basic movement is actually very useful when you are jogging.
せめてポールなしで歩く時にも大きく手を振ってみようかしら。 荷物を吹っ飛ばさない程度に（笑）。
I think I'd better try swing my arms big at least when walking, even without poles. I'll make sure I won't through my bag though.