This study involves imaging the skin movements of surface tissue on the back. A clinician will perform assessment and intervention procedures manually, using manual and light movements of stretch and compression.

This study includes a demographic questionnaire, self-report on level of pain, application of ink to the skin, manual clinical assessments, and a massage intervention. The study will take place entirely in Olsson Hall. All information collected will be recorded using a randomized identification number.

1. Upon arrival for the study, a participant will be asked to read, review, and sign this informed consent agreement.
2. Next, the participant will be asked verbally to complete a demographic questionnaire.
3. The study team will verbally ask the participant to rate the current level of pain.
4. The participant will have been asked to bring clothes (e.g., sports bra, halter top, or swimming suit, etc.) to expose the upper back/neck region, and will change into those in an isolated room and within the overall laboratory space. A gown will be provided for additional privacy.
5. Two researchers will be in the room during the session, with the gender of the researchers taken into account per participant. For example, for a male participant, the investigators plan to have a male researcher present during the session along with the female physical therapist. For a female participant, the investigators plan to have both the female physical therapist and a female researcher present.
6. The study team will apply non-toxic, washable ink to the participant's back in two 10 by 10 cm areas near the shoulder blades on either side of the body.
7. The participant will lie flat on a massage table.
8. A camera system will record the movements of the fingers of the physical therapist, along with the movements of the skin. The investigators will videotape the upper part of the participant's back. A participant's face will never be videotaped, nor will audio be recorded.
9. The physical therapist will conduct standard assessment procedures for about 2 minutes per side of the body, where the skin tissue will be compressed and slightly stretched
10. A soft tissue intervention, or massage, lasting about 15 minutes will take place in the participant's upper back/neck region.
11. Another assessment like that prior will be performed.
12. The participant will again be verbally asked about the current level of pain.

Inclusion Criteria:

• Healthy or diagnosed with benign, non-vascular headache and associated cervical musculoskeletal dysfunction (e.g. tender spots, trigger points, stiffness.
• Adult male and female.

Exclusion Criteria:

• Migraine headaches.
• Known cardiovascular, pulmonary, or metabolic disease.
• Any co-morbidities that could contribute to back or neck pain (e.g., head trauma, cancer, seizures, tumors, radiculopathies, rheumatoid arthritis, systemic auto-immune or inflammatory conditions).

Data obtained through this study may be provided to qualified researchers with academic interest in the area of soft tissue manipulation.

Data requests can be submitted starting 9 months after article publication and the data will be made accessible for up to 24 months. Extensions will be considered on a case-by-case basis.

Access to individual participant data can be requested by qualified researchers engaging in independent scientific research, and will be provided following review and approval of a research proposal and Statistical Analysis Plan (SAP) and execution of a Data Sharing Agreement (DSA). For more information or to submit a request, please contact gg7h@virginia.edu

From enrollment until end of follow-up, up to 1 week.

Adverse events were monitored throughout the intervention and post-assessment period. The licensed clinician completed standardized post-intervention assessment and follow-up check-in with participants a few hours after treatment.