How Strong Are Spiders Legs?
WouterIf you have ever wondered how strong are spiders legs, you are not alone. The smallest of the insects can lift eight times their own weight. Jumping spiders can jump thirty to forty times their own length. These creatures can also carry up to 173 times their own body weight. They also have the ability to walk on wet or slippery surfaces.
Spiders have seven different leg segments. Each segment is hinge-like and can bend in one direction. Each leg has special hairs with microscopic feet that enable the leg to grip the surface. A combination of hydraulic pressure and muscular contraction is used to extend and straighten the legs.
Each spider leg is supported by a thin, light chitin exoskeleton. The chitin is five times stronger than steel wires and is finer than human hair. The legs also have a thin membrane covering the fluid space within the skeleton.
The haemolymph (a fluid similar to blood) in the skeleton helps stiffen the leg structure. When the excess fluid flows back into the spider’s body, the pressure decreases and the leg is extended.
The hind legs are mainly supported by muscles while the frontal legs are primarily driven by the ground reaction forces. These forces are as strong as the force derived from the hind legs.
The muscles of the frontal legs are able to produce a net force of 0.025 N. However, the spider’s skeleton lacks bones that are able to support strong flexing muscles.
