Immediate Effects of Strain Counterstrain Versus Fascial Distortion Model on Upper Trapezius Latent Trigger Points

Musculoskeletal pain of the cervical region is a prevalent health problem, and the upper trapezius muscle is frequently involved due to postural overload and mechanical stress. These factors are commonly associated with the development of latent myofascial trigger points, which may restrict range of motion and impair neuromuscular function even in the absence of spontaneous pain.

Various manual therapy techniques have been used to manage myofascial trigger points. Strain counterstrain (SCS) is an indirect, low-intensity technique that aims to reduce nociceptive input and muscle spindle activity by positioning the body in a pain-free posture. In contrast, the fascial distortion model (FDM) is a direct manual therapy approach that applies relatively high-intensity pressure to specific fascial distortions identified through patient body language and palpation.

This study was designed as a pilot, parallel-group, pre-post comparative trial to explore the immediate effects of SCS and FDM on pain-related and neuromuscular outcomes in individuals with latent myofascial trigger points of the upper trapezius. Twenty healthy adults were randomly assigned to receive a single session of either SCS or FDM. Cervical range of motion, joint position error, pressure pain threshold, and cervical muscle strength were assessed before and immediately after the intervention. The findings of this study are intended to provide preliminary evidence to inform future large-scale clinical trials comparing manual therapy techniques with differing stimulation characteristics.

Inclusion criteria

• Healthy adults aged 18 to 39 years.
• Presence of latent myofascial trigger points in the upper trapezius muscle.
• No history of neurological or orthopedic disorders within the past six months.
• Willingness to participate and provision of written informed consent.

Exclusion criteria

• Current or previous complaints of neck or shoulder pain.
• Ongoing treatment for musculoskeletal conditions.
• History of physical therapy or chiropractic treatment within the past six months.
• History of surgery or trauma involving the head or upper trunk.