How Does A Giraffe Support Its Own Body Weight?

Have you ever wondered how a giraffe with its long legs and neck is able to stay upright? Scientists have puzzled over the same question and have seemed to find an answer. Scientists have found that the animals are able to remain standing because of a specialized ligament structure which they believe prevents the legs of a giraffe from collapsing under the immense weight of the animal.

Giraffes are heavy beasts, weighing roughly 1000 kilograms, and for their size have very skinny limb bones which means their leg bones are under high degrees of mechanical stress says Christ Basu who was the lead researcher.

The equivalent of our metacarpal bone and metatarsal bone which are located in our hand and foot respectively, for giraffes are extremely elongated. There is a distinct groove that runs along the length of these bones which house what is known as the suspensory ligament. This ligament can be found in a number of other large animals including horses, however for the first time the structure is being studied in giraffes.

As they sought to understand whether the ligament was why giraffes are able to support their own body weight, the researchers looked at donated limbs from zoos. The researchers took the limbs and fixed them into a rigid frame and they by using hydraulic press, applied a force of as much as 2500 Newtons in order to simulate the weight of a giraffes body.

What the researchers found was quite interesting, the limbs were able to remain stable and upright without the need for extra support. What was more surprising was the limbs were able to withstand much greater loads. The ligament looked to be providing passive support and this means that the giraffe is able to support its own body weight without actively engaging as much muscle which cuts down on fatigue.

“We hypothesize that the suspensory ligament has allowed giraffes to reach large sizes that they otherwise would not have been able to achieve,” said Basu.