WHEN Tanya Markova was just 12 years old, her life changed literally overnight when a rare disease of the spinal cord left her completely paralysed. “I woke up one day, wanted to get dressed and go to school,” says the Bulgarian-born student, who’s now 24. But suddenly she felt a sharp pain in her back and had to lie back down. Two hours later when she tried to get up, she could not move either her arms or her legs.
After the infection, she needed months of rehabilitation and two operations to get back to a halfway normal life. Markova still has problems with her right leg and walks slowly, laboriously setting one foot in front of the other. “I like to be able to run again.
I dream about it every night,” she says. Her doctors at the Rummelsberg Hospital in Schwarzenbruck, southern Germany are hoping an exact analysis of her gait will help her further. In a large room at the hospital’s gait analysis laboratory there are eight high-speed cameras with a resolution of 2 megapixels. Six cameras hang from the ceiling and two are placed at hip-height.
They take 100 pictures per second – recording far more than the human eye can distinguish. The images are used to create a three-dimenstional image of Tanya on a computer, which the doctors can slow right down and examine from all possible angles. For the analysis, Markova has to walk up and down the room a few times. Sports science graduate Verena Hirschmann and orthopaedic specialist Walter Strobl are on hand to help with the diagnosis. “You have to analyse a patient like Tanya very carefully,” says Strobl.
Their verdict? The muscles in her right thigh are too tense, while her tibialis anterior, a muscle in the lower leg which helps control the movement of the foot, is too weak. Another operation is now planned, to stretch one muscle and shorten the other.
Most laboratories, including that in Rummelsberg, use infrared light and reflective markers – in the form of lots of small plastic balls – stuck to the patients’ bodies.“ We want to move away from the markers though, and start analysing the patients’ silhouettes,” says Strobl, adding that the Rummelsberg laboratory is one of the first in the world to try such a technique.
Only a few markers are now needed. Analysing the silhouettes should make the examination easier, as it can be difficult to attach the markers to people with severe paralysis. New software can now recognise people’s joints without the markers, though the pictures produced are not yet good enough for scientific analysis. Dieter Rosenbaum of the University Clinic Munster says that an examination of the patients without using the markers would have clear benefits.
“You would not have to strip people down to their underwear, it would be quicker and we hope that it would also be cheaper,” he says. The Rummelsberger researchers now have to show that their pictures can compete with those produced by using infrared and markers. Gait and motion analysis are not new, says Strobl.
The first attempts began in the 1960s. The Society for the Analysis of Human Movement (Gamma) lists 18 registered laboratories in Germany, and four in Austria and Switzerland, though even more, such as that in Munster, are not listed.
The labs are usually used in cases of severe deformity, muscle weakness and walking disorders such as those suffered by people who have had polio or a stroke, or who develop Parkinson’s disease. In the 270,000-dollar laboratory in Rummeslberg, around 20 analyses a week are carried out. “But gait analysis has to be combined with a medical examination,” says Strobl.
Felix Stief of the Orthopaedic University Hospital Friedrichsheim in Frankfurt adds, “The most important thing is to view the data in an interdisciplinary way – the best way is with a doctor, a physiotherapist, or sports scientist or with a physicist.”
One of the benefits of a lab analysis in comparison to a normal method of diagnosis is that the data is completely objective, it provides exact angle measurements. How much does the upper body move? How far do the hips rotate inwards? “This way you can provide evidence to health insurers of whether a treatment is working,” says Stief.
Markova hopes that after her operation she will be able to live a “normal life” again. She wants to have children one day. “And for that you have to be able to run fast,” she says. – dpa
