Mechanisms of Musculoskeletal Physiotherapy

Musculoskelatal physiotherapy (MP) is a non-invasive intervention which uses therapeutic movement to help overcome problems with everyday movements that are predominantly a consequence of pain. MP is an interesting choice given that the pain of tissue insult galvanises the neuromuscular system into preventing or inhibiting movement in the interests of undisturbed repair. (For a variety of well-known reasons this situation may persist beyond the period presumed necessary for primary repair.) In order to overcome such a barrier successfully, movements administered or prescribed by MP must not only fail to increase pain; ideally they should be pain free and perhaps directly capable of diminishing that which is already present. Together, this implies that the neurological mechanism(s) underlying the clinical efficacy of MP is, at least in part, some type of ‘desensitisation’ or inhibitory process. Three distinct movement-mediated inhibitory mechanisms for achieving this effect are proposed. Several lines of evidence now endorse (passive) movement-evoked arousal of descending pain inhibitory systems. Though temporary, the respite afforded via this mechanism could be put to functionally significant use by resourceful clinicians. A rather more durable desensitising mechanism is likely to occur with what is known as ‘habituation’. Usually described in terms of (non-associative) learning theory, habituation is effectively a potentially lingering type of ‘activity-dependent’ presynaptic inhibition. Finally, and still in the area of learning theory, the ‘robust’ extinction of aversive memories would constitute a potent and lingering type of neural inhibitory mechanism for non-painful therapeutic movement. Behavioural and synaptic molecular mechanisms associated with this phenomenon are discussed along with their potential relevance to clinical MP.