Medical Research Council - London Institute of Medical Sciences

Now in our 9th year of bringing you beautiful imagery from biomedical science every day

Lazy Legs
07 October 2015

Lazy Legs

A person may take to the treadmill to get fit, but subconsciously their body is trying to spend the least energy possible. Scientists have known for decades that people minimise energy expenditure during movement, but what wasn’t clear was the time scale needed for such optimisation. It's been suggested that evolution tweaked our movement efficiency, and that further enhancements occur during a person’s development and life. But researchers now show that people monitor and adjust their locomotion continuously to maximise efficiency. In a recent study, scientists asked participants to don computer-controlled exoskeletons (pictured) while they increased or decreased (left and right) resistance to certain parts of the subjects’ legs. These tiny changes made the participants’ normal gaits ever so slightly more energy-demanding, and within minutes the subjects adapted to more efficient gaits. Exactly how the body monitors energy expenditure and executes these little energy-saving adjustments is the next question.

Written by Ruth Williams

Search The Archive

Submit An Image

What is BPoD?

BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.

Read More

BPoD is also available in Catalan at with translations by the University of Valencia.