Research in Pathokinesiology−−What, Why, and How
Joan M Walker
PHYS THER. 1986; 66:382-386.
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Research in Pathokinesiology—What, Why, and How
JOAN M. WALKER
Key Words: Pathokinesiology, Physical therapy.
The University of Southern California Department of Physical Therapy (USC-PT) is honored in being invited to present
a review of some of our research activities in pathokinesiology.
Specifically, I will address the following questions posed by
the organizers of this symposium: 1) Why has USC-PT been
conducting research in thefieldof pathokinesiology? 2) What
has been accomplished? 3) How was it accomplished? and 4)
How has this effort contributed, if it has, to the science of
pathokinesiology?
Many individuals deserve credit for providing the impetus,
inspiration, and opportunity to conduct research on normal
and abnormal movement. I recognize Dr. Helen Hislop,
Chairman of USC-PT and author of the pivotal paper "The
Not-So-Impossible Dream"1 that today retains its relevance.
As presenter, I am simply a voice for the many who have
contributed to these research efforts. The USC-PT effort has
been undertaken in cooperation with personnel from the local
area, particularly from Rancho Los Amigos Medical Center,
such as Dr. J. Perry, who is also a member of the USC-PT
faculty. Drs. R. Waters, J. Hackney, D. McNeal, and B.
Bowman have assisted with space, equipment, and financial
support.
We have taken a pragmatic and perhaps simplistic approach
to pathokinesiological research with emphasis on identifying
and answering questions that will provide clinically useful
data and a basis for the solution of clinical problems. Our
central mission at USC has been to build a body of knowledge
that will provide a solid foundation for the profession of
physical therapy and contribute to improved methods of
health care. Before analytical studies can be performed, normative data are needed.
The specific aims of our research into the science of pathokinesiology are as follows: 1) to develop methods to quantify
human performance with emphasis on the everyday activities
of human motion, such as gait and similar exercise demands;
2) to establish baseline data for healthy individuals (eg, sex,
age, race), "normative" values to which patient performance
can be compared, thus, permitting clearer definitions of disability and the extent of deconditioning that will assist in the
formulation of short-term and long-term goals for patients
and contribute to treatment response predictability; 3) to
establish data bases for various patient groups that will permit
the definition of grades of impairment within injury or disease
groups; and 4) to compare the performances of healthy and
patient groups and obtain quantitative measures of disability
important to the assessment of treatment effectiveness, employment potential, and disability pension reviews.
How has this effort contributed to the body of knowledge
of pathokinesiology? We have been involved in the development of the means to quantify human performance; for
example, the development of the Rancho Gait Analyzer,2
Dr. Walker is Associate Professor, Department of Physical Therapy, University of Southern California, Rancho Los Amigos Medical Center, 12933 Erickson Ave, Bldg 30, Downey, CA 90242 (USA).
which is designed for clinical use. We also have documented
the effects of exercise under adverse climatic conditions or
with muscle imbalance.3-5 Measurements are needed that can
be performed in the clinic without elaborate equipment or
extraordinary space. Refinement of testing methods will improve the quality of data needed to quantify patient performance. Results of testing are used to assess the severity of the
patient's problem and to reach decisions regarding the treatment program. The percentage of error of the measurements
used must be established so that changes in results on repeated
tests can be considered in the proper perspective. Adams (N.
J. Adams, unpublished data, March 1976) and other
researchers6-19 have accomplished this to some degree for gait
and for energy studies; these studies are still in progress.
Data in these areas have contributed to the establishment
of more realistic goals for the rehabilitation of patient groups,
such as those with spinal traumas, myelodysplasia, cerebral
palsy, hemiplegia, amputations, and fractures.13-15 The exertion requirements of activities such as crutch gaits in patients
with spinal traumas, fractures, or amputations have been
defined more clearly.14,16,20-23 The determination of endurance
limits for particular patient groups now allows a realistic
estimation of the feasibility of independent living (eg, a child
with myelodysplasia attending a regular school) or provides a
rationale for the acquisition of equipment for mobility (eg,
an electric wheelchair).
Without quantification of the energy cost of an activity,
poor patient performance (ie, less than that expected by health
care providers) may be thought to relate to inadequate motivation. Our energy cost data clearly show that motivation
alone will not allow some disabled individuals to perform
some routine activities on anything other than an occasional
basis.13,15,16,18,20-23 Eventually, the high energy demands of
such activities may seriously compromise the individual's
health.
Data regarding force, power, and work performed by both
healthy subjects and patients still are incomplete; these studies
are ongoing. Equipment for these studies is readily available
now, both in clinics and in laboratories of many physical
therapy education programs.
USC-PT RESEARCH EFFORT
Levels of Research
Research is a requirement in all of our programs: the entrylevel master's degree program, the advanced master's degree
program, and the doctoral degree program. Faculty members,
especially those in the tenure track, are expected to conduct
their own research programs. Ideally, students sponsored by
an individual faculty member will work on a project constituting part of that faculty member's research endeavor. Faculty members also conduct research in collaboration with
local clinicians. These collaborative efforts offer the greatest
potential for conducting analytical studies on the effects of
specific therapeutic approaches.
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PHYSICAL THERAPY
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PATHOKINESIOLOGY
Constraints on our research in pathokinesiology that still
require attention are insufficient laboratory space, equipment,
and human expertise in the form of mechanical and electrical
engineers and computer programmers; insufficient time, a
factor in entry-level student research; inadequate funding,
including the availability of faculty members who have the
ability to write grant proposals; and too few patient samples
with characteristics that are relatively homogeneous and data
that are collectable over a reasonable time period. Increasingly
restrictive medical, legal, and ethical restraints also exist; for
example, the use of muscle biopsies, roentgenograms, needle
electromyograms, and animal studies.
Existing constraints to pathokinesiological research may be
lessened by remembering the important interrelationships
between research plans, grants, and publications. These interrelationships, we believe, should enhance the successful acquisition of funds to support additional research efforts in
pathokinesiology and reduce the aforementioned constraints
to this research. The individual and the department as a whole
must have a research plan. Accomplishment of that plan
should result in the publication of research findings in a peerreviewed journal. Such publication enhances the potential for
future successful grant awards.
Master Plan
Our research effort has not been directed according to any
formal long-term master plan with a single theme. This is not
to say that the research has been conducted without any
direction. Rather, the effort has been directed by the identification of a clinically relevant problem out of which several
studies have developed. The completion of one study has led
often to the need to conduct further studies. Sometimes,
completion of a particular project is delayed because only a
certain number of students may work on one problem in any
one year and then with a less than desirable sample size. As a
result, similar studies may be conducted over a period of two
to five years to obtain an adequate sample size, to test both
sexes, or to test subjects representing different age groups.
Some examples would be the establishment of normative
temporal gait characteristics; range-of-motion studies; normative data for two-point discrimination; the study of daily
activities, such as the act of rising from a chair; or the day-today variability of routine clinical measurements.6-11,24-28 A
major impetus to the direction of our research efforts to date
has been provided by questions addressed in grants acquired
by the Rancho Los Amigos Medical Center (RLAMC) Pathokinesiology Service, and currently the RLAMC Rehabilitation Center, and the availability of equipment. Hislop's plan
to establish a regional pathokinesiology research center that
would serve clinicians, faculty members, and students is delayed because of the decrease in funds from major agencies.
What, then, has been accomplished in research efforts at
USC-PT? Between 1979 and 1983, about 120 studies were
completed by students and faculty members. Few studies were
conducted solely by a faculty member without student involvement. These 120 studies involved more than 170 entrylevel students and 25 advanced master's level students. Three
doctoral studies were completed during 1984. The majority
of these studies were descriptive or they were designed to
determine if differences existed between various groups.
Eleven of these studies were analytical. In 20 studies, the
results of testing patient and healthy groups were compared.
TABLE 1
Areas of University of Southern California Department of
Physical Therapy Research in Pathokinesiology, 1979-1985
Area
n
Energy cost
Force
Gait
Hemiplegia
Cardiovascular
Anaerobic threshold
Joint mobility
Electrical stimulation
Pediatrics
Physical therapy education
Nerve stimulation
Special senses
Miscellaneous
16
15
12
12
10
9
9
9
5
5
4
4
7
TABLE 2
Publication Sites of University of Southern California Department
of Physical Therapy Research Papers
Archives of Physical Medicine and Rehabilitation
Journal of Bone and Joint Surgery. American Volume
Clinical Orthopaedics and Related Research
Medicine and Science in Sports and Exercise
Developmental Medicine and Child Neurology
Physical Therapy
European Journal of Applied Physiology and Occupational
Physiology
Perceptual and Motor Skills
Circulation
Physiotherapy Canada
Journal of Applied Physiology
Journal of Orthopaedic and Sports Physical Therapy
Physical and Occupational Therapy in Geriatrics
Yale Journal of Biology and Medicine
Journal of Pediatric Orthopedics
Areas covered in these studies are presented in Table 1. Thirtyone studies examined energy cost or force-work-power abilities. Gait studies and studies on hemiplegic patients account
for 12 each. Thirty-seven studies have been conducted to
examine the cardiovascular responses to exercise, to identify
the anaerobic threshold, to assess joint mobility, and to measure the effects of electrical stimulation. Fewer studies have
been performed on children, nerve conduction characteristics,
physical therapy education, and the special senses. We also
have conducted basic studies at the tissue and cellular level,
investigating spinal cord programming and aging changes with
and without exercise, in muscles and in joints.
We estimate that since 1972 we have presented 67 papers
at national conferences, and we have published about 30
papers over the same time period. These papers were published in a variety of journals, which are listed in Table 2. No
journal entitled Pathokinesiology yet exists! The end point of
any worthwhile research project, however small-scale, is the
presentation of the findings at meetings and, if suitable,
submission of a paper for publication.
We must address the question, has this research effort made
a major contribution to the science of physical therapy, of
pathokinesiology? I will say yes but leave the degree of that
contribution to be assessed by others and time.
Volume 66 / Number 3, March 1986
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383
Strengths and Weaknesses
Among our strengths must be counted the exposure, just
in the last four years, of more than 200 physical therapists to
the research process. These experiences in designing and
conducting research in pathokinesiology should make them
more intelligent users of researchfindings,the only legitimate
basis for decision making in clinical practice. They also should
be more appreciative of the limitations and variability of
researchfindings.I hope that some of the former students will
continue to participate in research, even if only at the singlepatient level. Most of the research tools used in our studies
are tools that also can be found in clinics and hospitals with
patient testing laboratories. As studies were designed to answer
clinical questions or to provide normative data against which
to evaluate patient performance, the value of research to the
profession, in terms of improving patient care, should be
clear. Some unknowns have been identified, standards have
been formulated, and variability within healthy groups has
been established.
Results must be shared to ensure the growth of the body of
knowledge that will establish a recognizable science of pathokinesiology. We acknowledge that our publication efforts
have lagged behind completion of research studies. When
several students work on a clinical question over a period of
two to five years, someone else must analyze thefinalsample
and write the paper. An inadequate number of people have
been available to do that, to write grants, to supervise ongoing
research, and to fulfill normal faculty responsibilities. These
are problems familiar to most physical therapists. Furthermore, wefindthat students are keen to complete their research
projects because completion terminates their formal studies
and allows them to sit for the state board examination. In
theirfirstclinical appointment, however, conversion of their
accepted university paper to one suitable for submission for
publication in a professional journal has low priority, despite
prompting from faculty members. This problem decreases the
potential impact of the research conducted, but it has no easy
solution. We have changed from the thesis format to a directed
research format that permits the paper to be written in the
style of the journal to which it may be submitted. The number
of papers independently converted for publication and submitted by former students shows that this format change is
not enough. Where physical therapy faculty members are
highly involved in the supervision of student research, their
contribution to the science of pathokinesiology, and the overall development of the science of pathokinesiology, can be
lessened by high involvement with students below the doctoral
level of study. If the body of knowledge is to be increased, the
direction of those efforts of the still small number of adequately qualified and trained faculty members needs to be
reconsidered.
Other weaknesses in the research that may be identified but
not rectified easily are small sample sizes; subjects restricted
in age, geographic origin, and social group; inadequate use of
appropriate higher level statistical tests; a dearth of studies on
homogeneous patient groups; and absence of analytical studies investigating the effects of treatment regimens. These
factors, not unique to our situation, impede the growth of the
science of pathokinesiology.
We must discourage the tendency of the members of our
profession to speculate about the rationale for treatment based
384
on knowledge gained by the basic science studies and encourage documentation of the effects of physical therapy by actual
measurements of changes in physiological functions and physical characteristics. This documentation will define better the
scientific basis of physical therapy and will help define the
need for further studies. I believe that, despite research conducted in many places over the years, it is still true to say that
no physical therapy approach has been tested adequately.
Future Plans and Direction of Research
We plan to expand the vitally necessary normative data
bases and patient data. We need to obtain data on the characteristics and variability of patients with different disorders
and the degrees of those disorders. Do the gait characteristics
of a patient group, for example, vary with severity of the
disease? Can treatment also be assessed by monitoring improvement in walking? I selected gait because most people
walk in some manner, and tools such as the Rancho Gait
Analyzer,2 developed for use in the clinic, make it possible
for any therapist to quantify a patient's performance by the
measurement of the gait characteristics. How do members of
a specific patient group differ from healthy subjects? How do
they differ from other patient groups? Establishing these differences, if differences do exist, may contribute to the understanding of the disease process and the patient's rehabilitation.
When such data become available, we plan to place greater
emphasis, as conditions permit, on analytical studies to test
whether different treatments produce different effects, and if
so, what those effects are. We intend to continue to identify
variables that may affect data. Does the distance over which
gait data are collected, for example, influence those data?
What distance is ideal for an indoor gait walkway? What is
the influence of the time of day on data collection? Does it
matter? Should patients with disorders such as rheumatoid
arthritis only be tested after 10 AM? Is this hearsay or real?
What else is hearsay or real?
We also will expand the methods of data analysis. We, for
example, will make better use of multivariate and discriminant analyses; identify major variables that influence performance to determine which data should be collected; and improve the criteria for selection of candidates for specific
therapeutic interventions, such as strengthening programs or
functional electrical stimulation. These plans include educating physical therapy students to have exposure to research, to
gain a sound awareness of the importance of research to the
profession in providing the legitimate basis for clinical decision making, and to participate in some form of research in
their clinical practice.
We need to reevaluate the kinds and scope of research that
are requirements at the entry and advanced master's degree
levels. I believe that this component of our educational programs has the potential to affect significantly the development
of the science of pathokinesiology; to either increase or delay
its development. We need to identify the approach that will
be the most effective in achieving the goal of building a sound
knowledge base for the practice of physical therapy. Academic
requirements for student research must be balanced by the
necessity of allowing faculty members adequate time to perform their own responsibilities. As the number of doctoral
programs increases, the need for additional faculty members
to provide adequate supervision and to serve as role models
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PHYSICAL THERAPY
PATHOKINESIOLOGY
to their students also increases. In facilitating the acquisition
of grant monies by faculty members and in providing sound
training to the future physical therapy research leaders, faculty
members will need to determine where their time would be
spent most profitably—in giving research education to entrylevel students or to more advanced students, such as those at
the doctoral level.
A research laboratory, or laboratories, under the direction
and control of the physical therapy education program is
pivotal to the achievement of the objectives specified in a
research plan. A gait laboratory is a vital component. Humans
are bipedal and upright. Walking is a goal to be achieved by
most patients; thus, motor activity associated with gait is a
common denominator of health, injury, and disease. Change
in gait characteristics provides an index of motor ability and
independent function regardless of a patient's specific disease
or diagnostic label.
A thought for the future, indeed now, is contract research,
in which a research project will be conducted by faculty
members for a clinical group or a manufacturer of physical
therapy equipment, similar to the management of Department of Defense contracts. This may maximize the clinician's
skills and the research expertise available in the university
and in the clinical facilities. Such an arrangement should help
us obtain answers to the many questions posed by clinicians
who lack the time or facilities to pursue them.
The Research Process and Roles
To paraphrase a recent article on engineering by Harrison,29
the research process consists of selecting a problem, the methodology, and the protocol; executing the study; and reducing
the data. This process results in the development of constructs
that are useful in assessing the reliability of the results and in
establishing the clinical importance of statistically significant
results. The legacy of investigating clinical problems or phenomena will be scientific knowledge, a data base, an array of
methods, and an array of concepts. This is the legacy of
problem-solving investigations. This process of investigation
should lead to improved patient care, more efficient treatment
approaches, and more realistic predictions of the outcomes of
disease or injury.
To test, reevaluate, and revise constitutes the safeguard of
knowledge integrity. It is necessary and valuable for studies
to be repeated, in the same or different laboratories, to ensure
that the standards the profession may use are soundly based.
The exposure of students to the scientific process will
facilitate communication and collaboration among physical
therapy faculty members and scientists in university or private
research institutions and among clinicians. Endeavors to expand knowledge and the understanding of the scientific process are the responsibility of scientists and clinicians. These
two groups should maintain their distinctive roles and, in
their respective roles, serve as expert witnesses and advocates.
Clinicians more often adopt the role of the advocate. This
role is adopted when a value judgment is made in favor of a
particular therapeutic approach that then is supported over
other approaches (eg, neurodevelopmental therapy over proprioceptive neuromuscular facilitation or Williams's flexion
routine over MacKenzie's extension approach). This waives
the role of the expert who should have attained and demonstrated competence in a specific area of expertise. The expert,
Volume 66 / Number 3, March 1986
the scientist, is obligated to delineate, without prejudice, what
is known, what is not known, and what probably is known
using current methods.29 The advocate, the physical therapy
clinician, advances or defends a particular approach through
selective presentation of information to support that approach. The physical therapy clinician and the lay person
need to understand the uncertainty associated with scientific
knowledge and to understand the concept of probability.
Without this understanding, it is difficult, if not impossible,
to use scientific knowledge as a basis for decision making. I
hope that the research efforts of USC-PT not only have
contributed to the body of knowledge of pathokinesiology but
also have prepared clinicians to understand, use, and participate in the research process.
CONCLUSION
I end with a quote from Hislop's paper:
If you want a bee to make honey you do not issue directives
and protocols on carbohydrate metabolism and solar navigation. You put him together with other bees. If the air is right,
the science will come in its own season, like pure honey.1
In this review of one facility's efforts toward the development of the science of pathokinesiology, I have described and
discussed the many facets of research at our facility. Research,
scientific inquiry, is the sole means whereby the profession of
physical therapy stands to gain a sound scientific basis for its
practice. The growing body of knowledge of pathokinesiology
is that basis.
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Research in Pathokinesiology−−What, Why, and How
Joan M Walker
PHYS THER. 1986; 66:382-386.
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