The goal of this clinical trial is to learn if two common physical therapy approaches, used alone or together, can help reduce pain and improve daily function in adults with nonspecific low back pain. Nonspecific low back pain means low back pain without a clear medical cause.

The main questions this study aims to answer are:

1. Does hands-on pressure to painful muscle spots (called myofascial trigger point therapy) help lower low back pain?
2. Does a guided exercise program that focuses on how muscles work together help lower low back pain?
3. Does combining hands-on therapy with exercise work better than using either approach alone?

Researchers will compare three groups to see which approach leads to greater improvement. One group will receive hands-on trigger point therapy, one group will do a specific exercise program, and one group will receive both treatments.

Participants will:

• Be assigned to one of the three treatment groups by chance
• Receive treatment twice a week for four weeks
• Complete simple assessments before treatment starts, after the first treatment session, and after the final session

The results of this study may help physical therapists choose better noninvasive treatment options for people with nonspecific low back pain.

Non-specific low back pain is common, recurrent, and associated with substantial disability and health care use. In people with persistent symptoms, myofascial trigger points (MTrPs) are frequently identified and may contribute to heightened local pain sensitivity, restricted movement, and altered muscle recruitment patterns. In parallel, impaired kinetic-chain function and deficits in neuromuscular control are widely considered clinically relevant in nonspecific low back pain. From a myofascial perspective, regional symptoms may be influenced by force transmission and coordination across interconnected tissues and muscles within myofascial chains, particularly those spanning the trunk and lower extremity.

This trial is grounded in a combined framework that integrates (1) a local, noninvasive manual approach targeting MTrP-related pain sensitivity and mechanical irritability and (2) a function-oriented, myofascial chain-based exercise approach designed to address movement dysfunction and chain-level performance. The exercise program applies a functional classification model distinguishing stabilizer and mobilizer muscle roles. Stabilizer dysfunction is addressed through low-load inner-range holding strategies aimed at improving segmental control and endurance, whereas mobilizer dysfunction is addressed through sustained stretching strategies aimed at improving available range and reducing compensatory movement patterns. The central hypothesis is that combining these two approaches may provide complementary benefits by first reducing local pain sensitivity and then consolidating gains through task-relevant neuromuscular retraining and chain-based loading.

This study is an assessor-blinded, three-arm randomized controlled trial. Adults with nonspecific low back pain will be randomized to receive either (1) MTrP manual compression, (2) myofascial chain-based specific exercise, or (3) a combined intervention. Interventions will be delivered by trained physical therapists using standardized, protocol-driven procedures, twice weekly over four weeks. The protocol includes decision rules intended to standardize session content while allowing limited adjustment to individual presentation (e.g., selection of the most clinically relevant trigger point per target muscle and tailoring of exercise progression based on movement quality and compensations).

To evaluate both immediate and overall intervention effects, assessments will be conducted at three time points: prior to the first treatment session (baseline), immediately after the first session (immediate response), and after completion of the final treatment session (post-intervention). The outcomes are selected to reflect pain sensitivity, function and disability, and mechanistic/functional domains relevant to the study framework (e.g., chain-level performance, neuromuscular function, and lumbar movement capacity). Home program adherence will be monitored with participant logs for exercise-containing groups, supporting interpretation of treatment response in relation to dosage and compliance.

Treatment fidelity will be supported through therapist training, use of standardized procedures, and documentation of session content and dosage. Safety monitoring will be conducted throughout the intervention period. Because all interventions are noninvasive and commonly used in physical therapy practice, major adverse events are not expected; however, any discomfort, symptom exacerbation, or other adverse responses will be recorded and managed according to the protocol.

Inclusion Criteria:

• Adults aged 18 to 65 years
• Nonspecific low back pain lasting longer than 6 weeks
• Average low back pain intensity of 3 or higher on a 0-10 Numeric Pain Rating Scale
• Presence of at least 6 myofascial trigger points identified across bilateral target muscles
• Presence of muscle function impairments in at least 6 muscle groups based on functional muscle testing
• Able to understand study procedures and participate in an exercise-based intervention
• Willing and able to attend treatment sessions and complete study assessments

Exclusion Criteria:

• Currently pregnant
• Diagnosed spondylolisthesis or vertebral compression fracture
• Known malignancy or history of cancer affecting the spine
• Previous lumbar spine surgery
• Known neurological, infectious, or systemic disease that may affect pain or movement
• Any other medical condition that, in the opinion of the investigators, would interfere with safe participation in the study

There is currently no plan to share individual participant data. This decision may be re-evaluated upon study completion or at the time of publication.