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Interdisciplinary Vertical Integration:
The Future of Biomechanics
Robert J. Gregor
The field of biomechanics has grown rapidly in the past 30 years in both size and
complexity. As a result, the term might mean different things to different people.
This article addresses the issues facing the field in the form of challenges biomechanists face in the future. Because the field is so diverse, strength within the
different areas of biomechanics also varies. Although the term might not always
appear in the curriculum, principles in biomechanics are felt to be highly integrated
into the broader fields of kinesiology, exercise science, etc. The major challenges
facing the field, as suggested in this paper, include the development of significant
hypotheses, integration with other disciplines such as psychology and motor control, “cross training” our graduate students so they might bring a richer perspective
to collaborations with colleagues in other subdisciplines, and the development of
funded postdoctoral experiences to support this aspect of student development.
Because of the integrative nature of our work, questions are also posed related to
the use of particular names, which at times places us in possibly more-restricted
categories then we wish. These issues are, of course, open to debate.
The field of biomechanics has grown markedly in the past 30 years (e.g., the
American Society of Biomechanics (ASB) celebrated its 30th anniversary, the
International Society of Biomechanics (ISB) was 35 years old in 2007, and the 5th
World Congress in Biomechanics hosted a full week of parallel sessions on topics
ranging from cell mechanics to comparative neuromechanics in Munich in 2006).
During this period of rapid growth, the field of biomechanics also became more
diverse through its integration with related disciplines (e.g., rehabilitation medicine,
psychology, orthopedics, motor development, physiology, and neurophysiology).
As with any discipline, change is requisite to success and important in successfully
challenging students and colleagues to advance the field. The boundaries of subject
matter, course work, and research objectives have become more focused on integrative hypotheses and collaborative efforts in teaching, service, and research, and
general interests now overlap to the degree that rigid structures must be reevaluated
as possible impedances to the needed change. Integration has been a theme in science
and education for some time. Hence, the purpose of this article is to describe the
previous growth in the field of biomechanics and to provide examples using vertical
integration to suggest ways in which future challenges to our field can be addressed.
Transfer of these ideas to the development of undergraduate curriculum will not be
The author (AAPKE Fellow #465) is with the School of Applied Physiology, Georgia Institute of
Technology, Atlanta, GA 30332-0356. E-mail: [email protected]
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discussed because the content and relevance of the curriculum in biomechanics to
the movement sciences has recently been presented (Hamill, 2007).
Previously, Richard Nelson (Nelson, 1994) published a summary of progress
(i.e., 40 Years of Progress: Biomechanics in Exercise Science and Sports Medicine)
describing the growth of sports biomechanics in the United States and its relationship to the American College of Sports Medicine (ACSM). While concentrating
primarily on sport and sport injury applications, Dr. Nelson provided some very
interesting comments on the future of our discipline. These comments included
(a) “prospects of modifying the environment to meet the needs of each individual
offer unlimited opportunities to apply the science of biomechanics,”(p. 6) (b) the
rehabilitation/clinical area will expand, (c) influence in the industrial setting will
expand, (d) interaction between biomechanists, physiologists, and motor-control
specialists will become more common, and (e) as a word of caution, “high-tech
systems are no substitute for human thought” (p. 7). Sport and human performance
were two of the most-important applications of principles of biomechanics during
the 1960s and 1970s, but the comments made by Dr. Nelson apply to our current
challenges and will be discussed again later.
Further to the comments provided by Nelson (Nelson, 1994), Enoka (2004)
discussed the interface between biomechanics and neuroscience as affected by the
ACSM. There is general agreement that collaborations are successful only if the
individual disciplines of each scientist are strong. In this case, both biomechanics
(the study of structure and function of biological systems using the methods in
mechanics) and neuroscience (the study of the function of the brain and nervous
system) have a strong foundation in the ACSM with the current challenge being
the need for better communication/collaboration between these two disciplines as
it applies to the mission of the ACSM. The concept of integration and the development of strong questions or hypotheses produced through collaboration between
scientists from each field was the issue addressed by Enoka (2004). The need to
achieve this goal (i.e., to enhance the general communication between these two
disciplines within the College in this case) remains. Biomechanists, despite the
attraction of other society meetings, (e.g., ASB, ISB, Neuroscience, the World
Congress in Biomechanics, and student meetings for ASB) still maintain a strong
presence in the ACSM for discussions related to studies applied to sport and human
performance (Gregor, 2004). To reemphasize, however, biomechanists should
continue to join/integrate with other disciplines, presenting joint seminars, tutorials, symposia, etc. at meetings of all related societies, not just in reference to the
ACSM, and follow the natural interface of subject matter moving the integrated
field of movement science forward.
Integration
The lessons learned in the just-mentioned examples related to neuroscience, biomechanics, and the ACSM apply to all disciplines in the movement sciences whether
or not they are related to sport and sports medicine. Regardless of application
(e.g., the study of children at play, the study of falls prevention in the elderly, or
the study of individuals with physical or mental challenges in everyday life), the
overall principle of collaborative, interdisciplinary, integrative research and the
development of interdisciplinary educational training programs applies. Diane
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Gill (2007, p. 270) stated that “Integration is the key to sustaining kinesiology as
an academic and professional discipline in higher education.” Kinesiology is the
science of movement; biomechanics is a subdiscipline in that field. Integration of
all subdisciplines, when appropriate to address a specific question, is important.
Development of interdisciplinary research serving as the base for interdisciplinary
curricula is critical to our success in meeting the challenges of the future.
Gill (2007) focused on integration in three ways, the first focus being integration of our multidisciplinary scholarship (research) with a clear focus on physical
activity (movement science). Within the field of biomechanics, this integration
can occur with scientists in neural control, for example, interested in sensorimotor integration. Cell biologists, neurophysiologists, biomechanists, and behavioral
psychologists would collaborate to address the challenges of rehabilitating someone
with a specific movement disorder. Efficient gait for everyday activity might be the
objective, or achievement in sport performance might be the higher goal. Certainly
movement is the domain, and an interdisciplinary approach is warranted. Translation of this information to other clinical populations (e.g., stroke patients or even
children with cerebral palsy) addresses the challenges raised by Gill in her second
form of integration—integration of academic scholarship and professional practice.
Physical educators teaching adaptive classes or physical therapists dealing with these
special clinical populations should use the results of integrative research to improve
their education and/or rehabilitation of individuals with movement disorders. Of
course, these examples might also serve as models related to Gill’s third aspect of
integration, that is, public service. Certainly public service related to education and
rehabilitation of challenged populations is important and a general responsibility
of scientists and educators in all subdisciplines of kinesiology.
The opposite of these interdisciplinary integrative efforts is the problem of the
silos of information or the silos of curriculum content. Focus on a particular subject
matter and strengthening expertise in that discipline are essential to the development of any scientist and educator. Once strength has been achieved in a certain
area, however, it is incumbent on researchers and educators to reach out to other
disciplines, either by training themselves in another subject area (this relates to
interdisciplinary research, which will be addressed later) or by initially collaborating with others on a common problem. Strength in a particular subdiscipline comes
first but must be followed by collaborative, integrative efforts to solve problems.
In this regard, each scientist and educator “brings a certain set of tools or expertise
to the table” and then integrates his or her toolbox with others, making an even
larger set of tools to address a common problem (sharing is good). Generally, the
more tools you have, the greater the chance of solving the problem whether it be
in a research laboratory or in curriculum development where the explanation of
certain complex principles might be more-easily understood.
In the field of biomechanics, the silo approach comes at times not in the methodologies used (e.g., instrumentation used) but rather in the application of analysis
techniques to a given population. Sports biomechanists, for example, do not have to
study sport alone but can use the same tools and instrumentation to study movement
in less-skilled populations and learn a great deal about how principles in mechanics
and biology apply to all levels of performance capabilities. Likewise, scientists in
the basic sciences can use the same instrumentation to study particular aspects of
sport as an appropriate model.
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First Challenge
The first challenge to biomechanists in the near future is posed as a result of
conclusions drawn from the recent publication by Thomas and Reeve (2006),
which reported on 32 university programs in the United States offering programs in kinesiology or related disciplines. Of the 32 universities in the report,
17 had kinesiology in the department name. Of the top 10 schools reported,
50% did not have biomechanics listed in the graduate curriculum. It seems
then, that the first challenge to biomechanists is to make sure biomechanics
programs are offered in the graduate programs of the top 10 schools.
Does the silos-of-information approach detract from the integrative presentation of information in biomechanics and ultimately from its integration with other
disciplines in kinesiology, OR are we already integrated into larger domains within
kinesiology and therefore not specifically mentioned in graduate programs and
areas of research emphasis?
Is kinesiology the preferred name, or do some university departments feel other
names are equally appropriate? Can kinesiology also be considered a philosophical approach to curriculum development in that exercise science, human movement science, or human performance departments are philosophically the same as
kinesiology? Kinesiology is the science of movement with the objective to take an
integrative approach to the study of movement including, for example, mechanics, physiology, behavioral aspects of movement, etc. Because all of the programs
mentioned in the study (Thomas & Reeve, 2006) have very common objectives, is
using the name kinesiology requisite to achieving the goals? It might be the muchpreferred term but not always necessary. Likewise, does biomechanics have to be
specifically mentioned in the graduate curriculum to be inherent in the graduate
training? Again, it might be preferred but not always necessary.
It seems the answer is no in 50% of the top 10 schools in the report. It also
seems that the name kinesiology is not requisite to success, preferred, but not requisite to success in 47% of the schools in the report. These data suggest that we
already integrate material in our study of movement, and the science base used to
teach our students is already integrated. These data also suggest that success might
not require either the phrase kinesiology or the term biomechanics.
Our challenge is to study these results and use this information to continue
integrating material at both the graduate and undergraduate levels of education from
all subdisciplines. Counter the limitations imposed by silos of information, listen to
colleagues in other disciplines, think outside the box, and develop question-oriented
curricula and research programs that use the expanded toolbox available from the
integration of subdisciplines to approach challenges in kinesiology, movement
science, human performance, exercise science, and similar fields of study.
Interdisciplinary Integration
The terms integration, multidisciplinary, and interdisciplinary are widely used
in both research and curriculum development. Indeed, these forms of interaction are
preferred by administrators, funding agencies, and educators in general. Integration,
by definition, means the act or the instance of combining into an integral whole
Interdisciplinary Vertical Integration 35
(e.g., a harmonious whole) and is a widely used term common to all levels of education. In the context of this article, however, a distinction will be drawn between
multi- and interdisciplinary work. Multidisciplinary work involves the collective
efforts of a group of scientists well trained in a specific discipline. Each brings
his or her own specific toolbox to the table and relies on experts in other fields to
solve certain aspects of the problem being addresses. For example, the evaluation
of running efficiency might involve both biomechanical and physiological data. The
experiments might be conducted in a physiology laboratory using a treadmill, and
the biomechanics expert will bring or supply the motion-capture system and kinetics equations to help perform the analysis. It might also be done in a biomechanics
laboratory with a metabolic cart brought in for the indirect calorimetry measures.
The exercise physiologist relies on the biomechanist’s expertise and vice versa.
Two scientists trained in two separate disciplines are each relying on the other for
specific expertise needed to address the research goal (i.e., running efficiency).
Interdisciplinary research, on the other hand, involves scientists trained in more
than one discipline interacting to solve a problem. One example might involve an
individual trained as a physical therapist and as a biomechanist working with a
physical therapist also trained in cognitive neuroscience. The objective might be to
design an intervention to improve the quality of life of a physically and mentally
disabled child. The bond between the two investigators is training in physical
therapy, with the development of more-efficient movement patterns being the
goal of the interaction. One individual brings skills in movement quantification,
the other in the cognitive sciences. Although a very long list of examples could be
developed to explain the difference between multi- and interdisciplinary work, the
point is that scientists and educators trained in more than one discipline bring a
certain degree of richness to the interaction that can only benefit the situation. If a
graduate or undergraduate class were developed by the two scientists described in
the second example, it would be an interdisciplinary integration of course content
and very likely would provide a very rich environment for interactive, outside-ofthe-box thinking.
Second Challenge
The second challenge to biomechanists in the near future is to encourage
the training of our students in other disciplines in the movement sciences.
Postdoctoral experiences are growing, and new avenues and funding sources
must be developed to cross train our students and enrich their contribution
in both research and education. If someone has training and a vested interest
in two separate disciplines, their contributions will only further enrich the
collaboration.
Some methods of cross training currently used in many successful programs
include (a) laboratory rotations, which might be used to learn different skills or
might just be used to acquaint new students with the various laboratories in the
program; (b) minor areas of subject matter, which might focus, for example, on a
technical skill (e.g., statistics) or actually on a discipline other than biomechanics
(e.g., motor control); and (c) actually collecting data in another experimental setting, an integrative setting involving the students’ primary and secondary mentors.
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The idea here is not to build bigger silos but actually, especially at the graduate
and postgraduate levels, to break them down. Imagine common laboratory space
for biomechanical, physiological, and behavioral measures and common goals to
improve motor performance, movement efficiency, etc., with the resource being
a very large toolbox. Scientists and educators would be cross trained and able to
contribute in an enriched environment.
The challenge to biomechanists is to cross train their students—not just take
other classes, but to engage in another discipline, listen and learn and become familiar with hypotheses and ideas from a discipline other than biomechanics, and then
subsequently to make a larger contribution to a more-integrated problem. Integrated,
interdisciplinary research is fundable and supported at the university, state, and
federal levels. The greatest challenge to young faculty is indeed the dilemma that
independence (i.e., an independent focus to research) is one of the major criteria for
promotion and tenure, whereas integrated, interdisciplinary research is extremely
fundable. The message here, of course, is that strength must first be attained by
independent young scientists, and once this is achieved, they bring this strength
to the table in their future collaborative work.
Interdisciplinary Integration: An Example
The major areas of research and education in the School of Applied Physiology
at Georgia Tech are shown in Figure 1, indicating four major disciplines of study.
These include (1) exercise physiology, (2) motor control and motor behavior, (3)
biomechanics and neuromechanics, and (4) muscle physiology and cell biology.
Faculty in the School are truly interdisciplinary in that many of them, individually,
are trained in more than one discipline. This cross training mentioned previously
includes, for example, combinations of exercise physiology, systems physiology,
and biomechanics; mechanical engineering, cell biology, and systems physiology;
and neurophysiology, muscle physiology, and biomechanics. In some instances, data
can be collected in more than one discipline in the same laboratory, and in some
cases, two or more laboratories are involved. The School also has common laboratory space, specifically for muscle physiology, mechanics, and neuromechanics,
designed to support the faculty’s strong interest in interdisciplinary research.
Although at times department names are selected for reasons outside the
domain of science and education, philosophically, the School of Applied Physiology
teaches integrated systems physiology using the integration of disciplines common
to many kinesiology, exercise science, and departments of human performance
across the United States. The disciplines found in the School of Applied Physiology are also commonly found, but to a lesser degree currently, in departments of
physiology in the United States. When these well-established disciplines engage in
an integrated approach to research and education, whether it is multidisciplinary or
interdisciplinary as defined in this article, the field of kinesiology and movement
science in general move forward. In our case, the interests in systems physiology
move forward as well.
Interdisciplinary Vertical Integration 37
Figure 1 — Schematic diagram of the four disciplines in the School of Applied Physiology at Georgia Tech. Arrows show the strong interconnections and integrated interests of
the School faculty.
Vertical Integration
Vertical integration is analogous to the phrase molecules to movement. Vertical
integration of subject matter ranges from the study of molecules and cells to the
study of movement in a complex organ system (e.g., the human body). Laws that
govern the interaction of protein molecules (i.e., systems biology) might some
day be applied to the integrated interaction of physiological systems involved in
movement control. The plasticity of the human body in response to age, disease,
gender, or trauma exemplifies the interdependence of all physiological systems
designed to maintain the homeostasis of human function. The interdependence of
the respiratory and renal systems, for example, in maintaining blood pH during
acute exercise and the interdependence of the brain, spinal cord, peripheral nervous
system, and muscle in learning a new physical skill as a child or in response to
an intervention designed to attenuate falls in the elderly represent only two of a
large number of examples that could be used to make this point. Although the four
subdisciplines described in the previous section are interdependent, and faculty are
trained in interdisciplinary integration of material, vertical integration of subject
matter is the theme of the graduate curriculum in the School of Applied Physiology
at Georgia Tech. Three semesters of systems physiology, for example, start with cell
biology and end with a discussion of the integration and adaptation, and eventually
homeostasis, of physiological systems in response to interventions (e.g., trauma,
age). The text that follows focuses on two examples of vertical integration in which
knowledge of cell and tissue response, as well as knowledge of systems mechanics
and physiology, is needed in the investigation of a selected problem.
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Peripheral Nerve Injury
Peripheral nerve injuries are common, and despite the well-known capacity for these
injuries to heal, poor functional outcomes following peripheral nerve injuries remain
an important clinical problem. The Centers for Disease Control and Prevention
estimate that in 2002, more than 250,000 US patients suffered major traumatic
wounds to peripheral nerves. Probably because of the low efficacy of treating
peripheral nerve injuries, only about 15% of these patients were actually treated.
More than half of those patients who received treatment made no measurable signs
of recovery or suffered drastically reduced muscle strength or sensitivity. In addition,
more than 485,000 patients in 2002 were treated for nontraumatic peripheral nerve
injuries, the vast majority of which were attributed to nerve compression and
adhesion problems known as entrapment syndromes. The most common entrapment
syndrome is carpal tunnel syndrome, which has been studied and reported in the
biomechanics literature in human factors research.
Peripheral nerve injury results in both sensory and motor loss to the muscles
involved. Understanding recovery from such injury begins with the interface
between the motor neuron and the muscle cells (i.e., the motor endplate). Reinnervation of the muscle fiber is requisite to regaining motor function in the muscle.
Hence, the study of peripheral nerve injury and its effect on total-body motor function begins at the level of the cell (i.e., the motor endplate and muscle fiber). Unlike
development and synaptogenesis, reinnervation of the muscle fiber post traumatic
injury can be relatively complete depending on the severity of the injury. There
will remain, however, some loss of motor function.
Understanding the recovery process involves the vertical integration of information beginning at the level of the cell, on to the recovery of the whole muscle,
and eventual recovery of motor coordination in human performance. Knowledge
of cell behavior, muscle-fiber behavior, and whole-muscle function, function of the
integrated neuromuscular system, and eventually quantification of the recovery of
motor coordination will involve an understanding of cell physiology, neuromuscular integration, and biomechanics. An interdisciplinary scientist working on these
projects might have training in biomechanics, neurophysiology, and sensorimotor
integration, whereas another might have interdisciplinary training in neurophysiology and motor control. A third might have training in cell biology and muscle
physiology. Each would bring their interdisciplinary training to the group, and given
the overlap in expertise, the group would perform very effectively with common
interests and individual contributions.
The actual performance of muscle fibers in specific muscles (i.e., length changes
in muscle fascicles) and the electrical output of the whole muscle (which is representative of the use of that muscle in a given task) during recovery from peripheral
nerve injury are illustrated in Figure 2. This form of information represents the
next two steps in the vertical integration process (i.e., the level of the muscle fibers
and then the whole muscle including electrical and force output; see Figure 3 for
normal muscle). The analysis of total-joint mechanics during the recovery process,
a traditional approach taken in the field of biomechanics, represents the next level
of information (i.e., the mechanical output of the total joint integrating all muscles
involved in the control of the ankle during recovery; see Figure 4 for patterns of
joint moments during slope walking). Understanding the mechanics of joint function
is requisite to the final step in the integration process, a step involving analysis of
Figure 2 — EMG patterns and changes in muscle-fascicle length in the soleus muscle
during successive step cycles in over-ground walking. PC represents the point of ground
contact, and PO represents the end of stance and the beginning of swing. Notice the increase
in muscle-fascicle length immediately after ground contact together with a very high level
of muscle activity in the soleus at the beginning of stance.
Figure 3 — Electrical activity and muscle force from the gastrocnemius muscle during
a single step cycle in over-ground walking. Vertical lines (the line most left in the figure)
indicate ground contact and the beginning of stance, the second line represents the beginning of swing, and the last line is the end of the step cycle. Note the period of silence in the
muscle immediately after ground contact and that most of the force is developed during
stance. Note. Reprinted from Sherif, Gregor, Liu, Roy, and Hager (1983), with permission
from Elsevier.
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Figure 4 — Ankle-joint moment patterns during seven conditions of slope walking during
recovery from peripheral nerve injury involving the plantar flexors. Notice the increase in
peak moments and successively greater kinetic demands placed on the joint as slope intensity
varies from a 50% downslope to a 100% upslope (i.e., 45°).
the control and coordination of adjacent joints in the performance of a given task,
in this case locomotion (data not shown).
Application of the information obtained in this last step is relevant to studies in
other disciplines as well. For example, information related to total-joint mechanics
and mechanical work can be used in the study of gait efficiency, which might involve
exercise physiologists or scientists in motor control. In understanding movement
behaviors, one might find information about total-joint mechanics very useful in
the interpretation of behavioral outcomes. In short, there are a wide variety of interdisciplinary integrated investigations involving a variety of scientists and educators
from many subdisciplines (e.g., biomechanics) in which the process of vertically
integrating information from the cell to total-body performance is useful.
Knee Ligament Damage During Exercise
Some of the most-common injuries incurred during physical activity involve strains
or tears of a tendon and/or ligament in the knee joint. Magnitudes of the loads placed
on these tissues and, more important, the rate of loading of these tissues can be
extremely high during very strenuous activity in elite athletes (e.g., weightlifting;
Figure 5). While most musculoskeletal injuries do not occur under conditions permitting quantitative analysis, a single case study has been reported in the literature
involving the rupture of the patellar tendon during a weightlifting competition
(Whiting & Zernicke, 1998). During the second phase of a clean-and-jerk attempt,
a world-class lifter ruptured his patellar tendon. Using a rigid link biomechanical
model (Figure 5), the tensile load in the tendon at the time of rupture was estimated
Interdisciplinary Vertical Integration 41
Figure 5 — The figure at the left shows the “clean” portion of the clean-and-jerk weightlifting technique when the bar is resting near the shoulders of the lifter (Position 1 of graph
b). The figure on the right shows the calculated joint moment during five movement phases
in the “jerk” phase of the movement. Position 4 shows the largest knee moment and the
time of rupture of the patellar tendon. Note. Reprinted with permission from Whiting and
Zernicke (1998, p. 161). Originally adapted with permission from The Journal of Bone and
Joint Surgery, Inc. (Zernicke, Garhammer, & Jobe, 1977).
to be 17.5 times the individual’s body weight (i.e., 14.5 kN of load; Whiting &
Zernicke, 1998). Understanding this injury, planning a surgical approach, and
then recommending rehabilitation protocols involves the interdisciplinary vertical
integration of information from cell behavior to total-joint kinetics.
The development of any strength training program in an injury-free young
athlete should use the appropriate information regarding the ability of both hard
and soft tissues, bone and muscle, ligament and tendon, respectively, to withstand
load. Age, for example, will complicate the issue because the properties of the
muscle, tendon, ligament, and bone are dependent on age, initial degree of physical
activity and training, etc. When injury occurs (e.g., the patellar-tendon rupture
just mentioned), the surgeon should know the nature of the injury (e.g., the loads
involved at the time of injury) to plan a surgical approach. The surgeon will also
know the physiology and mechanics of the tissues involved and the general picture,
at the level of the cell, regarding how these tissues will recover. Kinesiologists
(e.g., biomechanists) study the science of movement, and movement, as we well
know, is critical to the recovery process in the example just mentioned. Although an
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understanding of tissue repair is important, using this information in the design of
a physical therapy program and extended, rehabilitative strength training program
is also important. At the level of the muscle-tendon unit, understanding aspects
of muscle stimulation, the load-sharing between muscles used synergistically to
control movement, and the general interdependence of other physiological systems
are all important to the recovery process. And maybe the most-important part of
the process is the psychology of recovery. The mental approach injured athletes
take in dealing with the recovery process, how they are encouraged to continue
with rehabilitation, is a critical element in recovery.
In this example, vertical integration of knowledge progresses from the level
of the cell, the tendon, muscle and the bone, to the level of the whole muscle,
synergistic groups of muscles, joint kinetics and interjoint coordination, and the
mental and behavioral approach to the recovery process. Certainly someone trained
in physical therapy and biomechanics could contribute to the recovery team, and
certainly someone trained in sports psychology, physical therapy, and generalsystems physiology would be a valuable member of the team.
Meeting Future Challenges
The growth of biomechanics over the past 30 years has resulted in such a broadly
based discipline that the name itself now means something different to different
people. As referenced in the paper by Hamill (2007), the 5th World Congress in
Biomechanics hosted a full week of parallel sessions, sometimes 16 parallel sessions
per day, invited lectures, and plenary sessions on topics ranging from cell mechanics
to cardiovascular fluid mechanics to sport movement analysis. Even within the
domain of human performance, the domain most aligned with kinesiology, the
topics in biomechanics are very broad. Because the discipline is so expansive,
my comments regarding future challenges in biomechanics will be restricted to
those most appropriate to human performance and the science of movement more
closely associated with kinesiology and physical education. In this regard, the future
challenges to the field of biomechanics as they relate to kinesiology and physical
education include the following:
• The development of hypothesis-driven research must continue to improve.
Some programs and scientists already have developed some interesting hypotheses driving their research, but improvement is needed here.
• Historically, biomechanics has been a technically driven discipline. As stated
at the beginning of this article, however, Nelson (1994) warned us that technology is no substitute for human thought. On many occasions, much of the
discussion in biomechanics is related to methods. Although understanding
the laws of physics and mechanics is requisite to successful science, so is the
development of good hypotheses (Challenge #1). The comments made by
Hamill (2007) on current challenges in undergraduate biomechanics classes
that focus on math and physics (i.e., challenges related to students’ interest in
the field) apply here. In this regard, our challenge might be to teach using a
top down approach rather than a bottom up approach. Instead of teaching all
the details of methodology to undergraduates, we should be teaching them why
Interdisciplinary Vertical Integration 43
the field is important. Get them excited. If they wait until their senior year to
integrate all the material and understand why biomechanics is an important
part of the curriculum, it will be too late. The top down approach dictates the
teaching of general principles to lower-division students, general hypotheses
in biomechanics that apply to human movement within the field. Once they see
these applications, then the specifics of how we study them can be taught.
• Make sure our subject matter is integrated into the general curriculum. This
issue was presented in Challenge #1 at the beginning of this article, discussed
elsewhere in the article forming questions designed to stimulate discussion, and
is extremely important to the integration concept. Fifty percent of the programs
in the top 10 programs reported by Thomas and Reeve (2006) did not mention
the field of biomechanics in their graduate curriculum. Maybe the information
is already integrated in the programs but not specified in the program description. Or, maybe the programs would like to have a biomechanist on site but do
not at the present time. I think the former answer is more correct and that the
principles in biomechanics are integrated into the existing program. If this is
not the case, biomechanists face another challenge, that is curriculum design
and the integration of our material into the current curriculum.
• Students in biomechanics, and I would assume in all disciplines, should be
cross trained in another discipline. Completing a minor concentration during
their graduate work is a start, but postdoctoral work serves this purpose much
better. The challenge here is to develop, use, and fund postdoctoral fellows,
students who have just completed their training in biomechanics, and train them
in another field. Although biomechanics seems better aligned with physiology,
neurophysiology, comparative zoology, rehabilitation medicine, prosthetics
and orthotics, and physical therapy, I feel a richer challenge is to integrate the
analysis of movement mechanics into the behavioral sciences (e.g., psychology). For example, biomechanists interested in learning in children about the
acquisition of a skilled movement pattern, should integrate their work with
scientists in psychology and motor behavior. Cognition, using fMRI scans to
study brain function during learning, and knowledge of mechanical outcomes
or the mechanical demands on the human system during the process of learning are all very important to the study of the overall developmental process
in children. The challenge is to expand existing programs that have already
started.
• Finally, the last challenge is to vertically integrate knowledge within the discipline of biomechanics, as well as our interdisciplinary efforts with scientists
in related fields. The two examples provided previously, vertically integrate
information within the field of biomechanics but also across fields such as cell
biology and electrophysiology. The systems person, and many biomechanists
in the human movement sciences are systems scientists, must look to the
level of the cell to properly evaluate human movement. Likewise, analyzing
and understanding the mechanics of interjoint coordination is important, but
collaborating with behavioral psychologists in these studies would stimulate
new questions requiring the synthesis of information across levels of study,
cells to organ systems, and across disciplines. We can no longer look to silos
44 Gregor
of information or take this limited view of science and be successful. The real
strength and future of biomechanics lies in the more-expanded, integrated
domains looking across levels of human performance and across traditional
disciplines. Being cross trained in interdisciplinary science will only enrich
this approach for the many challenges ahead.
References
Enoka, R.M. (2004). Biomechanics and neuroscience: A failure to communicate. In: C.
Oldham (Ed.), Advances in sports medicine and exercise science: 50 years of ACSM
(pp. 140–141). Tampa, FL: Faircount.
Gill, D. (2007). Integration: The key to sustaining kinesiology in higher education. Quest,
59, 270–286.
Gregor, R.J. (1993). Skeletal muscle mechanics and movement. In M.D. Grabiner (Ed.),
Current issues in biomechanics (pp. 171–211). Champaign, IL: Human Kinetics.
Gregor, R.J. (2004). ACSM: Biomechanics of movement performance. In: C. Oldham (Ed.),
Advances in sports medicine and exercise science: 50 years of ACSM (p. 102). Tampa,
FL: Faircount.
Hamill, J. (2007). Biomechanics curriculum: Its content and relevance to movement science. Quest, 59, 25–33.
Nelson, R.C. (1994). Biomechanics in exercise science and sports medicine. American College of Sports Medicine 40th anniversary lectures (pp. 1-9). Indianapolis, IN: American
College of Sports Medicine.
Sherif, M.H., Gregor, R.J., Liu, L.M., Roy, R.R., & Hager, C.L. (1983). Correlation of
myoelectric activity and muscle force during selected cat treadmill locomotion. Journal
of Biomechanics, 16, 691–701.
Thomas, J.R., & Reeve, T.G. (2006). A review and evaluation of doctoral programs
2000–2004 by the American Academy of Kinesiology and Physical Education. Quest,
58, 176–196.
Whiting, W.C., & Zernicke, R.F. (1998). Biomechanics of musculoskeletal injury. Champaign, IL: Human Kinetics.
Zernicke, R.F., Garhammer, J., & Jobe, F.W. (1977). Human patellar-tendon rupture: A
kinetic analysis. Journal of Bone and Joint Surgery, 59A, 179–193.