Messenger - Vol. 4, No. 3, Page T-3
On Technology
Biomechanics: Helping children and athletes improve

     A computer program being developed by the UD and the A.I. duPont
Institute, a children's hospital in Wilmington, Del., may some day
help surgeons correct disabilities that make walking difficult for
children with cerebral palsy.
     Because it shows life-like, side-by-side images of the child's
gait before and after surgery, the program should also help parents
understand the possible consequences of various surgical procedures,
reports James G. Richards, an associate professor in the University's
College of Physical Education, Athletics and Recreation. "Before
surgeons perform these procedures, they talk with the family about
what to expect," Richards says. "But, it's sometimes difficult for
parents to visualize how their child might walk after surgery. This
new computer program will let them see what might happen."
     Children with cerebral palsy often cannot walk more than a few
steps without resting because their movements tend to be spastic, and
sometimes their leg muscles are improperly aligned, says Dr. Freeman
Miller, director of the Gait Laboratory at the A.I. duPont Institute.
Doctors can perform a variety of surgical procedures, such as
repositioning thigh muscles, to improve a child's gait. But, surgeons
must use their best judgment to determine exactly how much of a
correction is needed. "Right now, these procedures are basically an
art form," Miller says. "An experienced surgeon has to decide whether
to move a muscle 10 degrees or 25 degrees, based on his or her prior
experience with similar cases."
     To take the guesswork out of surgery, Miller's research team has
already compiled data on about 30 children whose rectus muscles (those
attached to the kneecap) were surgically repositioned. In each case,
children were videotaped while walking before and after surgery.
Information from sensors attached to different muscle groups was then
fed into a database at the University. Thus far, Richards' research
group has enough information to complete a program that will predict
the impact of this surgical procedure. Additional programs are planned
to simulate the effects of different types of surgery.
     "We hope that this technology will give surgeons the ability to
make modifications before they go into the operating room, before they
even make the first incision," Richards says.
     Through biomechanical analysis conducted as part of the
University's Physical Education Program, athletes also can learn to
move more efficiently and perhaps even avoid injuries.
     Reflective markers are placed on ice skaters, baseball players
and other athletes, explains Richards. As the athlete jumps, runs or
throws a ball, specialized hardware records the movement of each
marker at a rate of 240 frames per second. Because the athlete's
movements are captured simultaneously by several different cameras, a
three-dimensional image is generated.
     Data from such images is then analyzed at a workstation. Software
developed by University researchers calculates, for instance, the
amount of stress each joint must endure at any given moment, or the
speed of a fast pitch.
     Working with student researchers, Richards has developed a
"composite" graph that shows the force typically required to pitch a
baseball effectively. The graph was developed by recording and then
analyzing the movements of 30 different pitchers. "If pitchers come
into the Biomechanics Laboratory and their pitch falls somewhere
within the normal range on our graph, then we know that they're in
pretty good shape," Richards explains. "If they're way outside the
norm, that almost always indicates that they're predisposed to
     Similar technologies allow University researchers to analyze the
performance of various types of footwear. "We work with major shoe
manufacturers on a regular basis to help them improve their designs,"
Richards says. "When it comes to athletic performance, shoes can
really make a difference."