[[1]] muscles consist of flexible muscle fibres.

Skeletal muscles are the muscles which are connected to the skeleton to form part of the mechanical system which moves the limbs and other parts of the body. They are responsible for skeletal movement. 

Skeletal muscles consist of flexible muscle fibres that range from less than half an inch to just over three inches in diameter. 

These fibres usually span the length of the muscle; they contract (tighten), which allows the muscles to move bones so you can perform lots of different movements.