First Era: Focus on Dysfunction of the Peripheral Neuromuscular and Musculoskeletal Systems

The first era involved the treatment of patients with peripheral neuromuscular or musculoskeletal system dysfunction as a result of war injuries or poliomyelitis. Manual testing of muscle for quantitative assessment of neurologic and muscular dysfunction was key in establishing the role of PT in diagnosis. Specific tests were performed, providing evaluation information to the physician, who would then formulate the diagnosis and define the extent of the dysfunction.

The relatively clear relationship between the loss of muscle function and the impairment of movement provided the direction for treatment. Although the relationship between motor unit loss and the consequences of weakness and loss of range of motion were defined, there was controversy surrounding the best management practices for patients with poliomyelitis, particularly during the acute phase of the illness. During this phase, the primary focus of treatment was to maintain range of motion through the use of stretching exercises and braces. During the recovery phase, exercises designed to strengthen the recovering and unaffected muscles were also important parts of the management of the patient’s condition. The most effective treatment included specific exercises that were based on the results of the manual muscle test. This information was also used to prescribe braces or other supports and to set expectations for functional performance. Precise exercises with careful consideration of each muscle and its directions of pull were keys to an optimal outcome. The role of the nervous system in activating muscle was certainly appreciated; however, the complexity of its role in regulating movement was not readily apparent in the patient with lower motor neuron dysfunction.

Second Era: Focus on Central Nervous System Dysfunction

With the eradication of poliomyelitis, patients with stroke, head or spinal cord injury, and cerebral palsy became the predominant patient populations receiving PT. Because the impairments in these patients were the result of central nervous system dysfunction, the previous methods used by physical therapists were no longer applicable. During this era the specific pathophysiology of movement problems that resulted from central nervous system dysfunction was not known. The methods of stretching and strengthening that were used in the treatment of the patient with poliomyelitis were considered unacceptable, because these methods were believed to augment the patient’s spasticity. Similarly, manual muscle testing was not considered an accurate indicator of muscle performance because spasticity was believed to augment the muscle response. The mechanisms contributing to impairments in the patient with neurologic dysfunction were not known. Therefore traditional methods of examination and treatment that were used in the management of the patient with musculoskeletal dysfunction were not considered acceptable. The lack of agreement surrounding the underlying mechanisms of the paresis and the suitable treatment meant that specific guidelines for the management of the patient with central nervous system dysfunction were not established. As a result, treatment regimens based on the clinician’s experiences and beliefs were developed. The lack of guidelines resulted in highly individual and eclectic treatment; unfortunately, this established a precedent of treatment based on loosely constructed hypotheses. This era also changed the relationship between diagnosis and treatment. The medical diagnoses of diseases of the central nervous system did not provide guidelines for PT treatment in contrast to the diagnosis of poliomyelitis in which the underlying physiologic problem was relatively well understood.

Physical therapists sought explanations for the mechanisms that contributed to the impairment of movement, as evident in the NUSTEP conference in 1967,² but as a result of the limited knowledge at the time, explanations that support clinical hypotheses concerning treatment mechanisms were necessarily vague and easily misconstrued. Unfortunately, the mechanisms of motor control still elude clear understanding, as do the mechanisms of the pathophysiology of movement impairments associated with central nervous system lesions. It became obvious during this period that the regulatory function of the nervous system is essential to movement. Although movement impairments associated with central nervous system dysfunction demonstrate the importance of the nervous system in movement, there remained a limited appreciation of the role of motor control and its contribution to musculoskeletal pain syndromes (MPS).

Third Era: Focus on Joint Dysfunction

In the 1980s, physical therapists, influenced by physiotherapists in Australia and New Zealand, began using assessment and treatment techniques directed primarily at joint function as the means of managing patients with musculoskeletal pain. These techniques required testing accessory joint motions and noting associated pain responses. This type of treatment was a departure from the standard, which emphasized the use of modalities to alleviate inflammation and the use of general exercises to strengthen muscles related to the affected segment. Some therapists also began using clinical methods advocated by Dr. James Cyriax³ to identify specific tissues that were the sources of the pain. Inherent in the use of these methods was a change in the role for the physical therapist. Previously, the physician prescribed treatment on the basis of the diagnosis. Although the majority of referrals merely directed the therapist to “evaluate and treat,” particularly when the problem involved the central nervous system, more specific direction was frequently provided for the treatment of the patient with musculoskeletal pain. Thus when the therapist examined joints to determine the source of the pain rather than applying modalities and prescribing a generalized exercise program to improve function, it was a significant change in practice.

Evaluating assessory joint motion represented a philosophical change for the profession; the focus became the identification of soft-tissue or joint restriction as the source of dysfunction, rather than the relief of pain with palliative modalities. However, because periarticular tissues and restricted joint motions were considered the primary problem, minimal consideration was given to the role that muscle and motor control plays in causing dysfunction. Another major development during this period was the classification of patients by directing him or her to perform movements of the spine to determine those movements associated with pain.¹¹

Current Era: Focus on the Movement System

During the 1990s, those with musculoskeletal pain have become the largest group of patients receiving PT.⁸ Thus the management of these patients is important to the profession. Providing treatment that addresses muscular, neurologic, or skeletal problems in isolation can only be considered incomplete and inadequate. The continued evolution of PT requires that movement remain the central focus. The American Physical Therapy Association adopted a philosophical statement clearly stating that movement dysfunction is the basic problem addressed by our intervention.¹

Movement is the action of a physiologic system that produces motion of the whole body or of its component parts.¹⁵ These components are the musculoskeletal, neurologic, cardiopulmonary, and metabolic systems. Thus this text is about the movement system and its contribution to movement impairment syndromes.

Because of my initial clinical interest in neurologic dysfunction, observing movement patterns almost became an obsession. Eventually I realized that everyone has a characteristic movement pattern, but these patterns are exaggerated in the patient with musculoskeletal pain. For the past 20 years, I have attempted to identify the organizing principles that best explain the characteristics of these movement patterns, their contributing factors, and why they are associated with or cause pain. Most of the explanations are based on clinical observations that have been used to guide treatment.

The observed clinical outcomes of treatment interventions have been used to refine the basic principles. Currently these principles are the subject of research studies that will further refine, modify, or refute the basic assumptions or syndrome descriptions. Although research is needed to validate these principles, they are based on well-accepted anatomic and kinesiologic relationships. The concepts of anatomy, kinesiology, and physiology that form the basis of PT education are the basis for assessing the patient’s muscle and movement performance.

The examination consists of (1) observing movement based on kinesiologic principles, and (2) testing muscle length and strength. Since the earliest days of the profession, physical therapists have used this type of examination to assess physical performance and to design exercise programs.⁹ This approach is named movement system balance (MSB) because of the importance of precise or balanced movement to the health of the movement system and its components. The MSB diagnostic and treatment scheme used by the physical therapist organizes basic information into syndromes or diagnostic categories and identifies the factors that contribute to the syndromes. The name of the syndrome identifies the primary dysfunction, or the movement impairment, and directs treatment.¹³ Neither outcome effectiveness nor cost containment will permit the physical therapist to continue to use a trial-and-error approach to patient care. This theory and the syndromes are presented with the expectation that others will join me in its validation and refinement.

Three main factors are key to the future growth of the PT profession. The first factor is developing diagnostic categories to direct treatment. The second factor is understanding and managing movement and movement-related dysfunctions and articulating the associated pathophysiology. The third factor is meeting the demands for evidence-based practice by conducting clinical trials based on diagnostic categories that direct PT treatment and knowledge of the underlying clinical science.