courtesy of David Perrin and Sandra J. Schultz
researchers are conducting several tests, using the device
at right, which records muscle responses when a sudden motion
makes participants attempt to stabilize the knee in response.
Why female athletes tear the anterior cruciate ligament, pictured
below, more often than males is the question U.Va. researchers
are trying to answer.
women get physical, knees take the brunt of it
Ida Lee Wootten
women and girls have made great strides in sports, their knees
may be paying a price.
high school, college and Olympic athletes, female players suffer
substantially more knee injuries than men. Injuries to the anterior
cruciate ligament (ACL), one of the primary stablizing ligaments
inside the knee, usually require six to nine months down-time,
which adds to athletes' physical and mental stress.
injury happens more frequently in sports that require changing
directions while running, cutting and landing from a jump, such
as basketball and soccer. Finding out why female athletes suffer
more ACL injuries than men and learning how to prevent such disabling
occurrences are some of the hottest research topics in sports
medicine and athletic training.
collaborative effort at U.Va. may be on the verge of finding some
answers. The National Institutes of Health has awarded researchers
in the Curry School
of Education's kinesiology department $222,000 to support
its investigation into why females participating in interscholastic
and intercollegiate sports experience injury to the anterior cruciate
ligament at a higher rate than males.
studies are probing the factors that may determine if females
have less joint stability and, therefore, experience lower tolerance
to stress on the knee joint. The central thrust of the research
is to determine the role that gender and hormones play in ACL
injuries and neuromuscular stability, according to principal investigator
David Perrin, the Joe Gieck Professor of Sports Medicine and chair
of the human services department, and study coordinator Sandra
Shultz, a research assistant professor.
researchers are taking blood samples daily from 20 collegiate
females during one complete menstrual cycle to determine estrogen,
progesterone and testosterone concentrations. The samples are
drawn after the females participate in a ligament stress test
that determines how much the joint is displaced when force is
applied to it.
-- the study of the art and science of human movement.
fall semester marked the beginning of a new area within
the Curry School of Education; the former health and physical
education program in the school's department of human services
has been renamed the kinesiology program.
... more accurately reflects what we do,² said Maureen Weiss,
professor and program director. Noting Thomas Jefferson's
quote that ³a strong body makes the mind strong,² Weiss
said the kinesiology program advances the discovery, development
and application of knowledge that relates the study of human
movement and physical activity to human well-being.
is a multidisciplinary field, focusing on the physical,
psychological, social and biological determinants and outcomes
of physical-activity participation in all its forms, such
as competitive and recreational sport, leisure-time physical
activity, exercise and fitness, and rehabilitation,² she
area's 15 faculty conduct research on the antecedents and
consequences of physical activity as well as teach courses
and seminars on how theory and research translate to practical
applications for fitness instructors, physical education
teachers, youth sport coaches, and athletic and physical
research efforts include the effects of exercise on cardiovascular
disease risk factors, gender-related risk factors in anterior
cruciate ligament injury (see story, above), exercise behavior
in middle-aged adults, and body composition in young and
older exercisers and non-exercisers. Other efforts focus
on attitudes of children with disabilities toward physical
education, goal-setting strategies to improve children's
fitness levels, peer relationships and children's psycho-social
development through sport, and teaching bilateral sport
skills to adolescents.
kinesiology area offers courses leading to bachelor's degrees
in teacher education and sports medicine, which gives students
the opportunity to pursue advanced studies in pedagogy or
the allied health sciences. Master's and doctoral degrees
are available in six specializations within kinesiology:
adapted physical education, athletic training/sports medicine,
exercise physiology, motor learning, sport and exercise
psychology, and teacher education/pedagogy.
and students are involved in numerous public service efforts,
including working with area agencies on the Special Olympics
and area schools in adapted physical education, motor learning
and teacher education. Faculty and students in the sport
and exercise psychology area work with national, regional
and local youth sports agencies on coach and parent education,
as well as with senior centers and fitness facilities on
aging and exercise issues. Sports medicine personnel perform
services at the McCue Center and the Kluge Children's Research
Center, and exercise physiologists perform services at the
General Clinical Research Center and the Adult Fitness Program
collegiate males serve as controls and are tested once every seven
days over a 28-day period after undergoing the same testing.
test the compliance of the knee, participants are placed in a
Telos Device that applies force to the back of the calf, causing
the lower leg to move forward relative to the thigh, stressing
the anterior cruciate ligament.
The studies will help the researchers understand the relationship
between hormone levels and how well the knee handles stress-loads.
"Fluctuation of sex hormones during a women's menstrual cycle
may have an impact on the ligament's compliance and how tight
or how loose the knee is," said Perrin. He noted that preliminary
studies have shown there is a difference in tightness and looseness
of the knee during menstrual cycles.
next step in the research could be to determine a link between
injury risk and elevations of hormones, Perrin and Shultz said.
a link is found, injuries could be prevented through several strategies.
One possibility would be to change women's hormone levels through
birth control pills. Another possibility would be engaging in
training programs to improve muscular control and knee protection.
Still another would be to start intervention strategies each month
before female athletes start their menstrual cycles.
work has lots of promise," said Perrin, who chaired a symposium
on the topic at an American College of Sports Medicine conference
if a link is not established, the research is important because
it is likely to determine what other factors come into play,"
investigation is based on Perrin's and Shultz's ongoing research
into how gender and lower extremity limb alignment affect muscle
reflex times and activation patterns. Supported by approximately
$53,500 to date from the National Athletic Trainers Association,
the studies are trying to determine how quickly and efficiently
knee muscles respond to joint stress.
test muscle responses, they designed a "lower extremity perturbation
device" that produces a sudden, unanticipated forward rotation
of the trunk and femur on the weight-bearing tibia. After experiencing
the perturbation, muscle responses are recorded as the test participants
attempt to stabilize the knee. Participants complete 10 trials
of both internal and external rotation; muscle activity and response
time are measured for analysis.
researchers have found that females tend to activate the front
thigh muscles faster than males, which may increase the stress
placed on the ACL. One factor that may explain the gender disparity
in sports-related injuries is differences in lower extremity limb
alignment, Shultz and Perrin believe. As a follow-up to this study,
they are evaluating the influence of excessive knee angulation
and flattened arches in feet, alignment faults commonly seen in
females due to their wider pelvises, on activation patterns at
support from the Health System's General Clinical Research Center,
the studies are being conducted in the Sports Medicine/Athletic
Training Research Laboratory in the kinesiology department of
U.Va.'s Curry School of Education. The Curry School researchers,
including Brent Arnold and Bruce Gansneder, are collaborating
with other colleagues across Grounds: Arie Rijke in materials
science and engineering, Susan Kirk in endocrinology, and Kevin
Granata in orthopedics and biomedical engineering.