The radius connects to many muscles, such as the biceps, supinator, flexor digitorum superficialis, flexor pollicis longus muscles, extensor ossis metacarpi pollicis, extensor primi internodii pollicis and the pronator teres muscles Furthermore, the radius is found on each arm thus contributing a total of two bones to the human body skeleton. http://www.learnbones.com/arm-bones-anatomy/
A normal adult human skeleton consists of 206 named bones (or 213 if each of the nine fused vertebrae of the sacrum and coccyx are counted as independent bones). The individual bones of the skeleton are connected by three types of joints, which differ in the type and amount of movement they allow. The human skeleton is divided functionally into an axial skeleton that supports the main body axis and an appendicular skeleton that supports the arms and legs.
The two shoulders are located beneath the head connecting the arm and the chest. Each shoulder consists of 2 bones, the clavicle and the scapula, and collectively both shoulders account for 4 bones in the body. http://www.learnbones.com/shoulder-bones-anatomy/