Which of the following is NOT a method to stimulate muscle tissue?

Cold compresses are designed primarily to reduce swelling, numb pain, and provide a cooling effect, rather than to stimulate muscle tissue. In contrast, the other methods listed are known to actively stimulate muscle tissue.

Heat and light rays increase blood flow and can enhance muscle metabolism, promoting relaxation and recovery. Nerve impulses are the body's electrical signals that trigger muscle contractions, essential for any kind of muscle activity. Chemicals, including those that may be found in topical treatments, can modify or stimulate muscle activity by affecting the biochemistry of muscle fibers.

Thus, while heat, nerve stimulation, and chemicals promote activity or enhance function in muscle tissues, cold compresses are primarily for alleviating discomfort and do not stimulate muscle activity.