1.   It took muscle to work in an old-fashioned kitchen.

2.   --- The basic mechanism by which muscles work is no mystery.

3.   Also, when the muscles work they produce a waste product called lactic acid.

4.   Burke, trained to watch how muscles work, immediately saw the deck as a great tool.

5.   Doing abdominal crunches and back extension exercises on the ball can be more challenging because muscles must work to stabilize the body while abdominal and back muscles contract.

6.   I have been so aware of that expectation that my jaw muscles have worked overtime.

7.   If one muscle is not working right, a pitcher will use other muscles to compensate.

8.   In hypertrophic cardiomyopathy, an overly thick heart muscle generally works well but can cause arrhythmia by limiting blood flow to the innermost part of the heart.

9.   The doctor then performed an electromyography, or EMG, a physiological test that studies how muscles are working.

10.   Therefore, its muscles must work more quickly.