Excess Fat Mass = Weak Legs in Older Women

Overweight women aged 65–80, take heed: Excess fat significantly impairs ambulation and leg strength, say researchers from the University of New Hampshire. The researchers separated 25 women into a normal-weight group and an overweight group. The women were tested for strength and rate of torque development in the knee extensors and flexors and the ankle plantarflexors and dorsiflexors. Then, during walking tests at standard and maximal speeds, the scientists measured muscle-activation, spatiotemporal and kinetic-gait variables.

“Relative to mass, overweight older women had 24% lower maximal torque and 38% lower rate of torque development than normal weight women,” reported the study authors. Overweight women also walked more slowly and took shorter strides, and they had lower vertical ground reaction force, longer foot-ground contact and double-limb support times and significantly greater knee extensor and plantarflexor activation.

“Overweight, older women demonstrated altered gait and reduced walking performance related to poor relative strength and rate of torque development of lower-extremity muscles,” the authors concluded. This population should take measures to lose weight and build strength in order to maintain or improve their gait and be better able to perform daily living activities, they added.

The study appeared in the Journal of Electromyography and Kinesiology (2011; 21 [5], 754–61).