The Kinetic Edge Approach to Functional Capacity Evaluation (FCE): Why Evaluator Philosophy Matters - Kinetic Edge Physical Therapy

by Dr. Troy Vander Molen, PT, DPT

For 20 years I have been performing a variety of assessments in the arena of work injury management and prevention. There are many strategies to help maintain a healthy and productive workforce, and each employer should consider their unique needs when determining solutions to their problems. One of those strategies is called a Functional Capacity Evaluation (FCE).

What is an FCE?

That question can be answered quite literally.

Functional means something that is meaningful or useful. In the context of an FCE, functional indicates purposeful activity that is an actual work movement. A functional activity has a beginning and an end, as well as a result that is measurable.

Capacity speaks to an individual’s maximum ability. It indicates existing abilities for activities including the maximal function identified through observation.

An evaluation is a systemic process of observing, reasoning, and correlating, which results in a conclusion. In other words, the evaluation process implies an outcome statement that is supported through objective measurement of the activity.


“The purpose of the evaluation is to stress the physical abilities of the client to safe maximum in order to accurately document observations regarding work and activities of daily living.”


Putting it all together, an FCE is a comprehensive, objective test of an individual’s ability to perform work-related tasks like lifting, carrying, pushing, pulling, gripping, pinching, bending, reaching, standing, walking, and stair climbing. The purpose of the evaluation is to stress the physical abilities of the client to safe maximum in order to accurately document observations regarding work and activities of daily living.

The outcome of the FCE can be used to for a variety of purposes including, but not limited to:

  • Providing objectivity to guide the return-to-work process for an employee after injury,
  • Justifying a referral for work rehabilitation, and
  • Highlighting necessary worksite modifications.

How can you determine a person’s safe maximum capacity?

There are several different philosophies that govern FCE providers in determining safe maximum capacity. My training in the FCE process was performed by WorkWell, a group that has been involved in this process since its infancy several decades ago. The WorkWell FCE process is considered a gold standard by many in the work injury management world.

The foundation of WorkWell’s FCE is a kinesiophysical approach whereby a skilled medical evaluator observes body movement and control, metabolic changes, pace, and various behaviors in one comprehensive functional evaluation. Those physical changes that are observed during the various functional movements help determine effort levels during the evaluation.

For example, when activity is performed at low effort, only primary muscles are needed to perform the movement. As the demand increases due to increases in the load or postural hold times, accessory muscles are automatically and involuntarily employed to assist the prime movers, and that will be apparent with observation of changes in body mechanics, balance, posture, heart rate, breathing rate, and movement quality.

I am a significant proponent of the kinesiophysical approach to functional capacity evaluation for a number of reasons. Most important to me, though, is the fact that as a rehabilitation professional, first and foremost, I have an ethical responsibility to care for my clients’ health and wellbeing in a conscientious and diligent manner.


The kinesiophysical approach, in my experience, allows me to best fulfill my most foundational ethical responsibility, which best serves all my clients – the patient, the employer, the insurer, and the employer.


In a 2011 Letter to the Editor of Work (Volume 38, 2011, p. 195), M.F. Reneman and D.P. Gross, researchers who have done substantial study on FCE processes, state the following: “It is doubtful that this ethical obligation can be met when we place ourselves in a situation whereby we are asked by a third party payer to judge the sincerity and legitimacy of our patients’ presenting problems for purposes of claims management decision-making. Ultimately, for patients, employers and insurers, it is much more constructive to conduct FCEs with a neutral or therapeutic [perspective] as opposed to a litigious perspective, because it may then be used to assist with facilitating work participation.”

The kinesiophysical approach, in my experience, allows me to best fulfill my most foundational ethical responsibility because it contributes to an atmosphere of trust and teamwork, and that type of testing environment best serves all my clients – the patient, the employer, the insurer, and the employer.

Is the kinesiophysical approach different than other FCE approaches?

There are other FCE philosophies that have some notable contrasts to the WorkWell kinesiophysical approach, most notably those that use what is known as a psychophysical approach.


“The evaluator uses criteria-based testing and acts as a coach, educator, and guide as he performs the evaluation with, not to, the client.”


In the WorkWell kinesiophysical approach, the therapist is a skilled evaluator that is in charge of the evaluation. The evaluator uses criteria-based testing and acts as a coach, educator, and guide as he performs the evaluation with, not to, the client. If the evaluator observes that the client is not putting forth full effort), he confronts the client in a positive manner and communicates with the client in a way that facilitates trust and cooperation, which typically leads to a more legitimate determination of safe maximal function.

The psychophysical approach, in contrast, allows the client to determine stopping points during testing. Therefore, the process can become more subjective since the evaluator is not observing true functional capabilities and full effort and, therefore, isn’t helping the client reach his/her safe maximal function.

Utilizing the kinesiophysical approach, the evaluator observes the client for consistency and uses integrated consistency checks. If inconsistencies are identified, the therapist’s goal is to further evaluate if there is any clinical rationale to support the inconsistency, which often leads to more fact seeking and critical conversations with the client.

The interpretation of results is not individualized and observational in the psychophysical approach. Rather, the results are typically based on formulas that do not take individualized evaluation into account and may negatively label the client by comparing their performance to norms or assigning improper motives to the observed inconsistencies.

Since the kinesiophysical approach simulates relationship between coach and athlete, teacher and student, safety is critical. When the client utilizes unsafe techniques during the FCE, the therapist stops the test and teaches the client how to perform the activity safely, a practice that often results in better functional measurements.

Client safety may not be emphasized in the psychophysical approach since it is not common for the evaluator to correct the client, and if correction is not provided, the client may assume that unsafe body mechanics are acceptable.

Ultimately, the kinesiophysical approach is essential for accurate work placement since the outcome has ensured safe maximum ability for the client, while the psychophysical approach may have limited usefulness in return-to-work since the results likely represent what the worker is willing to perform.

Why is rare so rare?

To objectively define exposure tolerance, the language of FCE reports use specific frequency or exposure definitions. The most commonly used definitions include the categories of never, occasionally, frequently, and continuously. The WorkWell process includes one additional frequency category: rare (Table 1).

Table 1. Definition of Frequency
Frequency % of Workday

Hours:Minutes

(8-hour day)

Never 0% 0:00
Rarely 1 – 5% 0:01 – 0:24
Occasionally 6 – 33% 0:25 – 2:40
Frequently 34 – 66% 2:41 – 5:20
Continuously 67 – 100% 5:21 – 8:00

It is important to note that in most FCE protocols, the maximum lifting capacity achieved by the client would be something the client would be approved to perform on an occasional basis since that is the lowest frequency category. Therefore, according to Table 1, we understand that the evaluator is clearing the client to perform lifting work at that level for a time period that may accumulate to a total of 33% of the workday (or up to 2:40 in an 8-hour workday).

By contrast, using the WorkWell protocol, the maximum lifting capacity would be the weight level that the client would be approved to perform on a rare basis, which means that the client could potential do lifting activities at that level of work for a time period that may accumulate to a total of 5% of the workday (or 0:24 in an 8-hour workday). This is more appropriate, which is easy to justify by considering a practical example.

During lifting portion of the WorkWell FCE, the client is asked to perform each type of lift at each weight level beginning with a light load for five repetitions. Typically, lifting of light loads can be accomplished quite easily and with a low effort level, which is confirmed using the kinesiophysical approach by observing in the client the use of only the primary muscle movers and with excellent, smooth body mechanics while experiencing minimal changes in heart rate and respiration.

At the conclusion of each weight level, additional weight is added until it is clear that the client has reached his safe maximum capability for that lifting task, which is confirmed by observing significant use of accessory muscles, less smooth movements, and noticeable changes in heart rate and respiration. The safe maximum five-repetition weight level is the level that the client is approved to lift on a rare basis (Table 1).

Now consider how you might perform in this lifting task. If we advanced the lifting demand until you were giving maximal effort and reached, for example, a 75-pound maximum on your waist to floor (i.e., squat) lift, which do you think is more likely to be your true frequency tolerance level to lifting objects that match your maximum lifting capacity in a real-world work environment? Up to 33% of the workday (2:40 in an 8-hour workday) or up to 5% of the workday (0:24 in an 8-hour workday)? The former (occasionally) would be the maximum capacity assigned to you by many FCE protocols while the latter (rarely) is the maximum capacity you would be approved to perform using the WorkWell approach.

Are FCEs error proof?

The WorkWell FCE protocol has been demonstrated to be reliable and reproducible. It has been supported by a significant amount of independent research, nearly one hundred peer reviewed articles, in fact, and it continues to evolve as scientific evidence grows. It is considered by many to be a gold standard for a reason, but, like each and every test and procedure used in medical professions, there exists some degree of error in any FCE process.

Indeed, there is error in some of the most basic measures we use in our standard physical therapy evaluation process. When we measure range of motion (ROM), research indicates that there is a +/- 5-10 degree margin of error. Although we recognize that the measurement is not perfect, we continue to use these fundamental measurements since they provide information on the status of a patient as various markers of improvement, particularly when we understand that changes of less than 5 to 10 degrees may not be statistically significant. Similar principles apply to other medical measurements in the medical field like blood pressure changes.

The overall result of a review of decades of research has determined that there is great value in FCEs despite their imperfections, and the body of research continues to accumulate and consistently advises the medical team and other stakeholders who rely upon the objective information to make solid, informed decisions.


The kinesiophysical approach is a unique blend of functional assessment and client coaching, an approach that is necessary to alleviate unnecessary errors and avoid inappropriate and subjective explanations of function in a process that is intended to be objective.


FCEs are not error proof, and they never will be, but it is important to understand the value they bring to the marketplace, which is understandable given that the snapshot of performance observed during an FCE is up to 20 times longer than the amount of time a physician dedicates to functional performance during a standard medical evaluation.

Perhaps more germane than the question of whether an FCE is error proof is an understanding of the assessment approach used by the evaluator during the FCE process. The kinesiophysical approach is a unique blend of functional assessment and client coaching, an approach that is necessary to alleviate unnecessary errors and avoid inappropriate and subjective explanations of function in a process that is intended to be objective.