Moving the forearm from anatomical position to the prone position is called pronation and is achieved by contracting the muscle.

It is achieved by the rhomboid muscle, examples where the rhomboid muscles can be seen are pronator quadratus in the forearm, rhomboids in the shoulder girdle and gluteus maximus in the hip region. if only elbow flexion is wanted, the pronator teres muscle contracts to counteract the supination component of the biceps muscle.

a. decomposes use carbon from dead organisms as fuel for cellular respiration, returning carbon dioxide back into the atmosphere.