The term proprioceptive system was first proposed by Sherrington more than 100 years ago (1). Sherrington also proposed that for movement to take place, there needs to be the excitation of one or more agonist muscle(s) with a simultaneous inhibition of the antagonist muscle(s) acting at the same joint (2). For these processes to occur smoothly, the brain must recognise the correct state of tonicity of each of the muscles involved.
In the 1960’s, following on from the work of Dr Carpinteiro on patients with rachialgia at the Department of Rehabilitation Medicine, University Hospital St Maria in Lisbon, Dr Martins da Cunha identified a wide range of symptoms in patients with aetiologies which could not be attributed to organic factors. After examining thousands of cases, Dr Martins da Cunha proposed a new clinical entity – the Postural Deficiency Syndrome (PDS) (now also referred to as Proprioception Dysfunction Syndrome), which he eventually published in 1979 (3). He also developed Dr Carpinteiro’s treatment further, to allow patients to rely less on frequent visits to the hospital. Dr Martins da Cunha named this treatment Postural Reprogramming.
As soon as I become the Director of Strabismus at the University Hospital St Maria in 1977, Dr Martins da Cunha sought my advice, bringing two of his patients with him. He wanted me to investigate why his patients with Postural Deficiency Syndrome had a particular way of looking at others “as if they were suspicious”, for no apparent reason. After observing how the first patient looked differently in both lateral positions, I modified the use of a Clement Clarke Synoptophore and to investigate what might be happening at the level of the gaze of both patients in the lateral positions.
These initial studies led me to develop a diagnostic protocol, Directional Scotometry, and to embark on the joint observation of hundreds of patients with Dr Martins da Cunha, and by 1978 to have developed an inexpensive, non-invasive, fast and accurate ophthalmological diagnostic protocol that allows to identify and categorise all forms of Postural Deficiency Syndrome. In 1979, I developed the use of Active Prisms, also known as Proprioceptive Prisms, for the treatment of each type of Postural Deficiency Syndrome.
Together with the treatment developed by Dr Martins da Cunha, my contribution allowed for:
Inexpensive, non-invasive, fast and accurate diagnostics of patients with Postural Deficiency Syndrome
Inexpensive, more effective treatments enabling patients to better manage their conditions, without relying on frequent visits to the hospital
The treatment of functional types of oculomotor discoordination, monocular diplopia, paracentral scotomas in the visual fields, convergence insufficiency, near exotropia, asthenopia and metatopsia
The understanding of the importance of the visual system in the Postural Deficiency Syndrome led us to identify a major, new and exciting chapter in Ophthalmology (4)
The treatment of a wider number of clinical cases that had previously not been possible, including that of certain types of cognitive dysfunctions and functional ataxia, dyspraxia, and various types of lack of balance and pain
The understanding of the extensive influence of the Proprioceptive System in the maintenance of human health
The understanding of the extensive and diverse impact of a dysfunction of the Proprioception System
The understanding that the Postural Deficiency Syndrome is the result of a dysfunction of the Proprioception System
The understanding that many symptoms of the Proprioception Dysfunction Syndrome are misdiagnosed as having an organic aetiology even when there is no evidence to that effect
A better understanding of the aetiology of the Proprioception Dysfunction Syndrome
The understanding that, when the Proprioceptive System is dysfunctional, the brain does not recognise the correct state of tonicity of the muscles at rest or in movement, and therefore Sherrington’s agonist/antagonist model is not applicable
The understanding that vaso-motricity is also affected as in PDS, the brain does not recognise the correct state of tonicity of vascular smooth muscle that is fundamental to regulate the caliber of the blood vessels
The understanding of why other treatments may also be effective
Our understandings would not have been possible without extensive multidisciplinary research, and the exchange of ideas and clinical practices, in particular during the late 1970’s and throughout the 1980’s and the 1990's, with leading researchers and clinicians from a variety of countries, including Portugal, France, Romania and Japan. We have presented our work at many international conferences and published various papers (see publications).
Note: the terms Proprioceptive System and Proprioception are frequently used interchangeably, even though this is a simplification. The term Proprioception Dysfunctions is used to mean Dysfunctions of the Proprioceptive System. Clinicians in France have more recently coined the term Dysproprioception.
Sherrington CS. On the proprioceptive system, especially in its reflex aspect. Brain, 1907; 29:467-85
See for example Burke RE. Sir Charles Sherrington's The integrative action of the nervous system: a centenary appreciation, Brain, 2007; 130, 4:887–894
Martins da Cunha H. Le syndrome de déficience posturale – S.D.P. Actualités en rééducation fonctionnelle et réadaptation, 4 série, L Simone Ed. Paris: Mallon, 1979.
Martins da Cunha H., Alves da Silva O. Syndrome de déficience posturale. Un Nouveau et Grand Chapitre de L’Olphtalmologie, J Fr Ophtalmol (Paris), 1986, 9:747-755