what is the function of the supraspinatus muscle
Supraspinatus muscle The supraspinatus muscle performs abduction of the arm, and pulls the head of the humerus medially towards the glenoid cavity.[5] It independently prevents the head of the humerus to slip inferiorly.[5] The supraspinatus works in cooperation with the deltoid muscle to perform abduction, including when the arm is in adducted position.[5] Beyond 15 degrees the deltoid muscle becomes increasingly more effective at abducting the arm and becomes the main propagator of this action.[6]
Lateral corticospinal tract Descending motor pathways carry motor signals from the brain down the spinal cord and to the target muscle or organ. They typically consist of an upper motor neuron and a lower motor neuron. The lateral corticospinal tract is a descending motor pathway that begins in the cerebral cortex, decussates in the pyramids of the lower medulla[1] (also known as the medulla oblongata or the cervicomedullary junction, which is the most posterior division of the brain[2]) and proceeds down the contralateral side of the spinal cord. It is the largest part of the corticospinal tract. It extends throughout the entire length of the medulla spinalis, and on transverse section appears as an oval area in front of the posterior column and medial to the posterior spinocerebellar tract.