Muscle PTSD, Predictive Processing, and Reinforcement Learning: Reimagining and Treating Non-Specific Musculoskeletal Disorders as Mind/Body Conditions

Abstract

Non-organic (muscle) weakness (NOw) is proposed as a distinct pathological entity characterized by maladaptive neuroplasticity (learning) affecting motor control. Functional deficits are most directly revealed through the manual muscle testing (MMT) break test, which uniquely exposes a muscle’s ability to adapt to increasing external load, potentially serving as an index of motor control integrity. We advance the “muscle-motor-movement PTSD” (mPTSD) model in which learning during pain or stress (trauma) yields chronic avoidance (inhibition) of the associated muscles. In a second stage, compensatory synergies develop, overriding attempts at hypertrophy-oriented training. This non-systematic, integrative review synthesizes clinical reports, learning theories, motor control and pain literature, and objective tests of force and movement over time during MMT. Predictive processing and reinforcement learning offer complementary accounts of how hyper-precise priors and passive avoidance may maintain NOw beyond functional recovery. Unexplained muscle weakness is found in non-specific musculoskeletal disorders and functional motor disorder (functional weakness), but may also contribute to other conditions, such as kinesiophobia. Effective alternative treatments for NOw may act by updating or erasing maladaptive motor learning by disrupting memory reconsolidation, allowing immediate restoration of function. Analogous to psychoneuroimmunology’s role in immune function, we propose “psychoneurokinesiology”, the study of how maladaptive learning affects movement.