ODD THINGS YOU CAN DO WITH YOUR BODY # 1
Make your arms float
Standing in a doorway, allow your arms to come away from your sides until they meet the doorframe. Now push firmly out wards against the frame and keep the pressure up for a minute. When you release the pressure and walk out of the doorframe your arms will feel like they are floating upwards.
The reason for this is that you are performing an isometric muscle contraction with the Deltoid muscle. That is to say that you are asking the muscle to contract but not letting it shorten. By holding the contraction you are reinforcing the neural signals to push the arms outwards. At the same time there is the phenomenon of synergistic muscles which causes one muscle to relax as another contracts. For example, when you bend your arm at the elbow you need the bicep to contract but you also need the tricep (at the back of the arm) to relax. If they both contracted together the arm would not move.
When you walk out from the doorway the neural stimulation causes the deltoid muscles to continue contracting to a small degree and the synergistic muscles are inhibited making the arms feel as though they are floating upwards.
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