The reason a Chiropractor in Denver performs the  Surface electromyography and Thermography testing at your initial and subsequent evaluations is to assess measurable  improvement of your spine and nerve system that cannot be seen on X-Ray:

1) Surface electromyography (Myovision S-EMG Scan) to assess the electrical current in the muscles. Your muscles are controlled by nerves. The SEMG measures how well the motor nerves are working by reading the amount of current found in the muscles. Spinal Subluxations disturb nerve flow and cause an abnormal amount of electrical current to flow to your muscles. Additionally, altered spinal position or brain function creates muscle imbalance. This reveals an increased amount of tension/pull on one side compare to the other (similar to a tug of war.)

2) Temperature Differences  (Tytron Thermography)
When the communication between the nerve system and your blood vessels is disturbed the body’s thermostat malfunctions producing an imbalanced temperature reading along the spine. These blood vessels are controlled by the same part of the Central Nerve System that coordinates your organs, glands and body chemistry, your autonomic system. Temperature differences beyond 1/2 a degree can be neurologically pathological. (Umatsu) Additionally, a non changing reading indicates a nerve system that fails to adapt to stress appropriately. (Palmer)