In hands-on healthcare, especially in osteopathic manual practice, assessment is central to the choice of methods utilized when interacting with a patient (1,2). With the preceding as our starting point, it is important to acknowledge several things that are common in any hands-on healthcare practice with respect to assessment. Broadly, hands-on healthcare is performed with the environment of observation being external to the patient. Stated differently, hands-on healthcare is unable to accurately observe past the skin of the patient. It will be acknowledged that the chiropractors utilize periodic x-ray images with, depending on the particular research cited, a high degree of variance and frequency (3), day to day practice does not include a new x-ray image. Again, stated another way, some hands-on healthcare practitioners have access to the ability to produce radiological images of patients however these images are not taken at every patient interaction. The lack of images at every patient interaction supports the claim that hands-on healthcare is broadly performed at the level of an external environment of observation. 

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Following from the argument that hands-on health care is performed from an external environment of observation, it is possible to consider some of the common challenges associated with assessment in hands-on health. Please keep in mind that the vast majority of this argument is based on evidence from osteopathy with a high degree of likelihood that this evidence does generalize due to the external environment of observation common to hands-on healthcare. The first issue to be highlighted is palpatory accuracy. The ability to accurately identify specific structures with palpation has problems. It will be clearly stated that the assessment of reliability or validity of palpation is generally performed on smaller structures (i.e. a spinous process and not a humerus) so it does make superficial sense that accurate identification of structures has problems. If we consider the validity of utilizing palpation to identify lumbo-pelvic structures we are able to identify that low levels of accuracy make it difficult to argue that palpation may be claimed to accurately identify landmarks (4). Along with issues of validity there is further observation that accurate identification of structures is generally low with palpation (5,6). In order to be explicit, prior to furthering this discussion we will note that the term validity broadly describes the level of confidence that a measurement is assessing what it says it is (7) and reliability broadly describes how consistent an assessment is with respect to the normal range of results it provides (8). Please note that the broad definitions of validity (7) and reliability (8) do specifically come from educational assessment; however, the broad sentiment is consistent with any form of testing/assessment. 

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With the apparent lack of accuracy to identify landmarks/structures with palpation (4–6) we may predict issues with the reliability of palpation. When considering agreement between individuals with palpatory assessment we are able to note that it is generally poor but does improve on specific types of assessment with consensus training (9,10). Consensus training, essentially training individuals to perform the same tests the same way, does lead to improvement with respect to the identification of tenderness (pain provocation) and tissue texture (variations in yield to pressure broadly) but not in the identification of static asymmetry or dynamic asymmetry of lumbar landmarks (9,10). There is some interesting evidence that expertise (essentially experience across time) far more than specified training improves reliability with respect to palpation identifying the location of a heel lift (11). 

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Instead of simply noting the challenges presented by assessment methods performed by hands-on healthcare practitioners, we will use the same evidence (plus more) to build a model for how to leverage current assessment methods. The initial signal to concern ourselves with does have a negative valence which is accuracy/validity. The current attempts at accuracy in identification of structures is less than ideal (4–6) which would primarily predict that accuracy claims may be worth abandoning. The second signal already presented is that consensus training improves interobserver reliability (9,10) for assessment tissue texture and tenderness which allows for the prediction that consistent assessment methods might improve reliability. Further, in experts who have received specific training, intraobserver reliability has shown improvement for identification of the location of a heel lift (11) which further supports the prediction that consistent assessment methods might improve reliability. The third concern is where a new line of evidence will provide insight. The third concern stems from the issues surrounding palpation such that, instead of maintaining the cognitive paradigm that palpation is the primary assessment method in hands-on health care and that osteopathic practitioners have “seeing and listening hands” (12). In order to shift out of the paradigm that palpation is primary in hands-on assessment we are able to identify observational studies of osteopathic practitioners that note the use of both palpation and vision during assessment (12–14) as well as textbooks which explicitly note the use of both visual and palpatory assessments (1,2,15). It is important to note that observation of practitioners assessing patients in the hopes of generating a classification system of the assessment methods displays that the categories are all based on motion, including deep and superficial palpation which is achieved by applying pressure to soft tissues which will generate yield or resistance as a quality of motion (13).