Patients with cervical spine pathology can have respiratory system dysfunction due to weakness of respiratory muscles including diaphragm or involvement of the respiratory center and lower cranial nerves secondary to medullary compression. Pulmonary aspiration, atelectasis, poor respiratory function, and inadequate cough mechanism secondary to the diaphragm or respiratory muscle involvement can lead to preoperative respiratory abnormalities in patients with cervical spine pathology that might get exaggerated in the postoperative period because of various anesthetic and surgical causes.

Respiratory function is controlled by the phrenic (C3–C5) nerves, the intercostals (T2–10) nerves,  and autonomic nerve, especially the sympathetic (T1–L3) nerves. Therefore, smooth and effective breathing under normal conditions would be impaired by disrupting descending neural pathways at any level in the cervical spine. People with respiratory muscle weakness have a higher risk of PPCs. This is thought to be due to inspiratory muscle fatigue leading to the collapse of alveoli. Even if the impairment of neural function was subclinical, the effect might lead to the deterioration of pulmonary function during the acute postoperative stage. PPCs are comprised of atelectasis, bronchospasm, respiratory failure, pneumonia, and ARDS.

There are several techniques for preoperative respiratory optimization. However, the commonly used IS had been found to have little benefit. IMT can be defined as a technique that aims to improve the function of the inspiratory muscles through specific breathing exercises to increase strength and endurance of the respiratory muscles and therefore improve respiration.   Several authors have reported that preoperative IMT resulted in significant improvement in mean inspiratory muscle strength and endurance after thoracic and abdominal surgery without causing adverse effects.Preoperative IMT has been shown to decrease the incidence of PPCs in patients undergoing cardiac and major abdominal surgery. Thus, it is reasonable to assume that an increase in inspiratory muscle strength and endurance through preoperative IMT can lead to better‐quality deep breathing after surgery, which would in turn result in a decreased incidence of PPCs in patients with cervical myelopathy who have a pre-existing muscle dysfunction.

There are no studies on the role of preoperative muscle training with IMT in patients with cervical myelopathy. In the present study, we have compared pulmonary function after IMT in cervical myelopathy patients and have looked for the incidence of PPCs.