In studies carried out, keeping fixed of the head in direct position for looking on blackboard with high height create some pain in lower neck area and thoracic vertebra and this pain brings to arms and causes to some side effects such as headache, nausea, perspiration and vertigo. This position cause to increased scoliosis in cervical in long-term, so the neck muscles will short and rhomboid and trapezoid muscles will be spastic and painful [16].