tonus

And, of course, one should feel something if it is no more than the tonus of muscle against the mobile bones.

The tonus of the muscles at the moment of examination may create differences inappreciable during relaxation.

This tonus is essential to the maintenance of an equalized circulation.

He drove powerfully with his wings, felt tonus across his back, shot forward and up.

The moral tonus of the place will be let down appreciably; general laxness will be the rule.