Neurological level for complete SCI, typical respiratory impairment and support [123, 155, 159, 160]
| Neurological level | Dysfunction |
| C1–C3 | Likely full time, ventilator dependent secondary to severe diaphragm weakness (paralysis) May be able to come off ventilation for brief period if able to adequately self-ventilate using frog/GPB Potential candidate for diaphragm pacing [155] |
| C3–C4 | Diaphragm function will be impaired, reducing tidal volume and vital capacity Periods of unassisted ventilation (ventilator-free time) are likely and may be adequately supported with nocturnal ventilation alone Domiciliary ventilatory support may be noninvasive, particularly if lung volumes are high enough during day while seated |
| C5 | Independent respiration possible in long term although initial ventilatory support common Diaphragm function intact but intercostal and abdominal muscle paralysis results in decreased lung volumes, and cough strength and effectiveness |
| C6–8 | Independent breathing People with lesions caudal to C7 typically can augment inspiration and cough with accessory muscles, particularly pectoralis major and minor |
| T1–T4 | Inspiratory capacity and forced expiration supported by intercostal activity; however, cough efficacy remains reduced secondary to abdominal (expiratory) weakness |
| T5–T12 | Progressive relative improvement in muscle strength at descending lesion levels Minimal disruption to autonomic dysfunction affecting the cardiovascular system below T6 |
| T12 | Respiratory function essentially comparable to that of an able-bodied person |