Pregnant runners, there is hope yet
THERE are changes that happen in a woman's body when she is pregnant, and those changes can linger and significantly affect her running stride.
More pregnant women and new mothers run today, and many experience aches and pains and a niggling feeling that their stride has somehow changed.
Dr Bryan Heiderscheit, director of the running clinic at the University of Wisconsin in Madison, conducted studies examining running biomechanics in women's pregnancy and post-partum periods.
The early results, published in The Journal Of Orthopaedic & Sports Physical Therapy, are among the first to look into how those changes might be managed.
One of the cases involved a 27-year-old runner who, beginning in the sixth month of her pregnancy, began visiting the exercise lab every four weeks. Scientists used 3-D motion-capture technology to study her running form.
The scientists found that as her pregnancy progressed, her pelvis began tilting forward, altering how she landed during each stride.
Six months after giving birth, much of that forward tilt remained. She also displayed more side-to-side pelvic motion while running.
Another post-partum runner was a 33-year-old mother of two who visited the running clinic 14 months after her second child was born, because of considerable hip and lower-back pain while running.
After she ran on the lab treadmill, the researchers determined that her pelvis tilted forward abnormally during running and moved too much from side to side.
Her pelvis remained unstable a year after her last pregnancy. Her right leg struck the ground harder than the left, absorbing about 30 per cent more force with each stride.
"Pregnancy and labour stretch the muscles and connective tissues in the abdomen", which allows the slightly unmoored pelvis to tilt and sway, said Dr Heiderscheit.
Unless a woman strengthens the affected muscles after pregnancy, the tissues will remain stretched.
Crunches won't do the trick, though. Dr Heiderscheit suggested pulling the belly up and in multiple times, and "imagining that you're trying to cut off the flow of urine".
These techniques, together with traditional abdominal exercises like squats, planks and bridges, can help stabilise the pelvic area.
The studies suggested that women shorten their stride by about 10 per cent to reduce the pounding that they experience while running.
"I think it's time we acknowledged that having a baby is going to change how you run," Dr Heiderscheit said.
There is no evidence that a majority of mothers are slower runners or are more injury-prone after giving birth.
"But things are likely to feel different, and probably for a long time", he said.