By Michael P. Reiman, PT, and Robert C. Manske, PT
“Functional” can be defined in various ways. Functional activities have been defined as “those activities identified by an individual as essential to support physical, social, and psychological well-being and to create a personal sense of meaningful living” (American Physical Therapy Association 2001). Austin (2007) defines function as “any movement at the level of the person that is task related, goal oriented, environmentally germane and involves the integration of multiple body systems and structures.” “Testing” is defined as using a set of problems to assess abilities. Therefore, “functional performance testing” means using a set of tests to determine performance abilities or functional limitations. A functional limitation is the inability to perform a particular activity at a normal level (American Physical Therapy Association 2001). “Normal” should be based on such factors as a client’s age, sex, body type, and occupation. Normative values are highly dependent on the tasks in the specific sport or occupation and their associated demands or requirements. Normative values are determined via collection of data on large numbers of subjects performing a task.
More specifically for this book, functional testing is defined as using a variety of physical skills and tests to determine (1) one’s ability to participate at the desired level in sport, an occupation, or recreation or to return to participation in a safe and timely manner without functional limitations and (2) one’s ability to move through up to three planes of movement as assessed via nontraditional testing that provides qualitative and quantitative information related to specialized motions involved in sport, occupation, and exercises. Functional performance is an aspect of everyday life, whether for the elite athlete, the industrial worker, the homemaker, or anyone else. The commonality among all groups is that some aspect of performance is needed for them to be successful in performing their respective skills or duties.
Successful performance often requires multiple skills, and sometimes these multiple skills are difficult to assess and quantify. For this reason clinicians may use multiple functional performance tests depending on the set of physical attributes they need to assess. We believe that these tests or series of tests can be used to determine functional performance outcomes. Scores on functional performance tests should help to predict the level of activity at which a client can perform or to which the client can safely return. For clients who are reimbursed by third-party payers, functional performance outcome scores may provide justification for reimbursement or for the need for further rehabilitation or care, or conversely, justification that further care is not needed.
In the case of clients who have been injured, immediately after injury there is normally, at minimum, a brief period of impairment. Impairment is a dysfunction or a significant structural abnormality in a specific body part or system (Verbrugge & Jette 1994). Of importance in our context, the abnormality can have consequences for physical functioning (Verbrugge & Jette 1994). It is during the immediate postinjury period that the more classical objective measures of physical function are used, such as range of motion, anthropometry, muscle strength, reflexes, and joint integrity. These measures are somewhat generic in that taken as a whole, they indicate the ability of the body or system to perform work. But, although these clinical examination measures are important, they do not appear to correlate directly with actual physical function. This is the reason for functional performance testing. The lack of clinical correlation also makes it imperative that functional testing as described in this book be performed to ensure that the individual can safely return to the given activity.
Compared to the classical objective measures of physical function, functional performance testing more closely mimics physical activities that people wish to return to. For example, the fact that a person has full shoulder range of motion does not mean that he or she can throw a softball far enough to return to full unrestricted play. If this same person has full range of motion, full strength, and full neuromuscular control and additionally is able to achieve an excellent score on the Underkoffler softball throw without adverse symptoms, we are much more confident about the prospect of a safe return to unrestricted overhead throwing activities. Even though some feel that observing the performance of an individual’s usual activities is time-consuming (Verbrugge & Jette 1994), many functional tests closely approximate the activities that people need or wish to do.
Physical performance tests have varying amounts of complexity and impose different levels of physical demand. The clinician should ensure that testing is at the appropriate level and occurs at the appropriate time for the individual client. Functional performance testing should not be done in a random, haphazard manner. As with any objective measurement used to assess an injured client, one should carefully evaluate the appropriateness of each test before introducing it. For example, a client who is only six weeks post anterior cruciate ligament reconstruction is not an appropriate candidate for performance of the single-leg hop test. This test would be far too aggressive. It would be more appropriate and much safer to use the single-leg timed stance. Davies and Zillmer’s (2000) functional testing algorithm (FTA) is an objective, systematic, functional-based testing progression according to which the client must pass one level of functional performance testing before proceeding to a higher-level test. The FTA appears to provide a safe and effective way to perform a variety of testing maneuvers. Chapter 3 describes the use of the FTA in detail.
This is an excerpt from Functional Testing in Human Performance.