From Reuters Health Information

Patellofemoral Problems May Prompt Hip Muscle Weakness in Women Runners

By David Douglas

NEW YORK (Reuters Health) Jun 14 - Hip muscle weakness in female novice recreational runners may be due to patellofemoral malalignment and the development of the patellofemoral dysfunction syndrome (PFDS), Belgian authors say.

More work is needed to confirm the direction of association - but if the authors are right, it's the reverse of what some assumed to be the case.

"Out of the results of the study, we concluded that isometric hip muscle strength might not be a predisposing factor for the development of PFDS," Dr. Youri Thijs told Reuters Health by email.

"(Instead) we suggest that hip muscle weakness in PFDS patients rather might be a consequence than a cause of the pathology."

Dr. Thijs and colleagues at Ghent University note that PFDS is the most prevalent injury in runners, and as public interest in running grows, more people are at risk for this knee condition

Whether hip weakness is a cause or an effect is unclear. To investigate further, the researchers studied 77 women, enrolling them just before they began a "start to run" training program, according to a June 1st online paper in The American Journal of Sports Medicine.

All were sedentary and asymptomatic at the time of entry. During the 10-week training period, 16 developed patellofemoral pain. There were no significant differences in age, height, weight, and body mass index between this group and the others.

Also, say the investigators, "the strength of none of the different hip muscle groups of the female runners who developed patellofemoral pain differed significantly from those of the asymptomatic runners."

This is contrary to the findings of some other researchers, but it's conceivable that their subjects "developed a decrease in hip muscle strength attributable to disuse atrophy from reduced activity caused by the long presence of the patellofemoral pain."

The team says hip muscle strength is worthy of evaluation in patients with PFDS syndrome. "However, on the basis of the information from this study, we cannot conclude that decreased isometric strength of the hip muscles predisposes people to the development of PFDS," the researchers add.

For further information: http://www.medscape.com/viewarticle/744548?src=mp&spon=8