Manual therapy (MT) is widely used in clinical practice, but the immediate mechanisms behind its effects remain debated. A study on Germany-wide cross-sectional online survey (July–October 2023) explored how physical therapists perceive the anatomical and physiological processes involved in MT. Using a fictitious case of cervical mobilization, the study examined therapists’ beliefs about which structures and mechanisms contribute to immediate pain relief and improved mobility.

Methods

• Design: Online survey, preregistered, ethics approved (University of Luebeck).
• Participants: 569 licensed German physical therapists (mean age 36.5 years, 58% women). Most worked with musculoskeletal patients in outpatient clinics; 77% had postgraduate MT training.
• Scenario: A patient with restricted right cervical rotation receives passive mobilization at C4/5, resulting in immediate pain relief and improved range of motion.
• Ratings: Therapists scored the involvement of anatomical structures and mechanisms (0–100 scale).

Key Findings

Perceived Involved Structures

• Brain (75%), myofascial tissues (71%), peripheral nervous system (68%), and cervical joints (60%) were most often believed to contribute.
• Spinal cord (25%) and intervertebral discs (18%) were viewed as less relevant.
• Additional structures suggested included the autonomic nervous system and joint capsules.

Perceived Involved Mechanisms

• Majority endorsed endogenous pain modulation (73%), placebo/contextual factors (72%), muscle activity regulation (68%), neuromuscular reactions (62%), and blood circulation (56%).
• Less than half supported joint biomechanics (47%) or inflammatory mediators (38%).
• Therapists also suggested psychological factors such as security and patient validation.

Predictors of Beliefs

• Beliefs about structure/mechanism involvement were only modestly linked to demographics.
• Male sex, greater hands-on practice, and lower academic degree predicted stronger belief in biomechanical explanations (spinal joints, myofascia, blood flow).
• Belief in placebo mechanisms was more common among therapists with less hands-on time and experience.

Perceived Effectiveness

• Cervical mobilization was rated 66% effective (on a 0–100 scale) for immediate relief.
• Therapists’ belief in spinal joint and myofascial involvement explained 31% of perceived effectiveness.
• Belief in muscle activity, joint biomechanics, and endogenous pain modulation, combined with less belief in placebo, explained 26% of perceived effectiveness.

Discussion for Therapists
This survey highlights the ongoing tension between neurophysiological and biomechanical explanations of MT. Most therapists endorsed central mechanisms such as brain involvement, pain modulation, and contextual (placebo-like) effects, aligning with current evidence from neuroimaging and pain science. Still, many also relied on traditional biomechanical concepts, despite mixed or weak supporting evidence.

Interestingly, therapists’ own beliefs strongly influenced how effective they perceived MT to be. This underscores the role of expectations, communication, and therapeutic alliance in shaping patient outcomes. The findings also suggest a gap between mechanistic research and clinical practice—likely perpetuated by outdated teaching materials and persistent biomedical models.

Clinical Implications

• Therapists should remain aware that central mechanisms and contextual factors (expectation, trust, therapeutic alliance) play a significant role in MT outcomes.
• Overemphasis on biomechanical “corrections” may not only lack strong evidence but could reinforce unhelpful beliefs in patients (e.g., structural fragility).
• Education that integrates pain neuroscience, contextual factors, and patient-centered communication may enhance therapeutic outcomes.
• Therapists’ own beliefs and confidence can amplify placebo analgesia and patient trust, making reflective practice crucial.

Conclusion
German physical therapists perceive both central and peripheral mechanisms as driving the effects of manual therapy, though neurophysiological and contextual factors dominate. Therapists’ beliefs themselves significantly shape perceived treatment effectiveness, reinforcing the importance of reflective, evidence-informed practice. Bridging the gap between evolving mechanistic research and clinical teaching remains essential to optimize patient care.