Why Muscles Respond to Massage:

The neuromuscular junction is where the motor neuron (nerve) meets with muscle tissue. During massage, a different nerve signal is sent to the muscle, allowing a tight muscle to contract less, as well as toning a loose muscle. This is called resetting the muscle resting length. Massage will re-educate the muscle and will promote proper functioning.

Increased circulation of blood and nutrients to the muscle also encourages enhanced function.
Click here to see an actual photo of a neuromuscular junction.