The historical evolution of the six-minute walk test as a measure of functional exercise capacity: a narrative review
Chronic disorders are usually associated with impairment of functional capacity (ability to perform activities of daily living), hence, necessitating routine evaluation and monitoring of this impairment at baseline and in response to interventions as part of standard of care. The six-minute walk test (6MWT) is one of the most common modalities for the measurement, monitoring and prognostication of functional capacity. Since its development in the early 1980s, it has witnessed an increasing use as a valid and reliable tool for the objective quantification of the functional capacity of children, adolescents and adults with various chronic cardiopulmonary, haematologic, neuromuscular and metabolic disorders. It has become the most widely used tool for the evaluation of functional capacity by physicians, physical therapists, physiologists, rehabilitation specialists and nurse practitioners involved in the care of adults and children with these disorders. There exists a rich and growing body of literature on the evolution of this test from pre-existing measures of functional capacity, its measurement properties and utility in various adult and paediatric chronic disorders, as well as reference standards derived from healthy paediatric and adult populations. This review chronicles the landmark milestones in the evolution of this test and provides an up-to-date reference of important contributions to the development of the test for clinicians and researchers. Thus, it not only fills a need for the historical background of this test, but also provides a rich reference source of key works on different aspects of the test for the benefit of clinicians and researchers. The documentation of the historical background of clinical tests may also serve as inspiration for practitioners to be curious and innovative as they seek to optimise patients’ care and functioning.