Ultrasound can be a good first step in calming muscle spasm. If you are suffering from tension headaches, ultrasound treatments on the back of your neck may help relieve muscle spasm and help alleviate your headaches. Some combination of massage, mobilization, exercise, and ice packs can also calm muscle spasms.
You need to look at possible causes of your tension headaches. You or your therapist should check your work station to see if your postures, lighting, or repetitive tasks could be to blame for your headaches. Stress management might also be in order.