Diaphragm strengthening is recommended for all patients with less than normal vital capacity. Patients with lower thoracic or lumbar lesions and a fair or better grade of diaphragm strength are usually candidates for progressive resistive exercises until they regain full activity. Patients with cervical and high thoracic lesions and a less than fair grade of diaphragm strength are usually candidates for active-assistive exercises.

1. Progressive Resistive Exercises, with weights, manually, with positioning, and incentive inspiratory spriometry, for example, should allow the diaphragm to contract through its full range, to prevent altering the patient's normal breathing pattern, and should be done carefully to prevent fatiguing the diaphragm, with the patient in a lying position:
   • Weights - After the placing the patient in supine, the therapist places a diaphragm weight pan over the epigastric region, without the pan resting on the ribs which can prevent full excursion. The amount of weight used as resistance should allow the epigastric rise to be the same as before the weight is applied. If the diaphragm is innervated, 5 pound weights can usually be used at first. When the patient can maintain a coordinated, unaltered breathing pattern for 15 minutes, with full epigastric rise and without substituting the sternocleidomastoid muscles, the weight can be increased until the patient's strength reaches an acceptable plateau, such as vital capacity remaining the same in a subsequent evaluation, or the patient being able to tolerate full activity with early signs of fatigue.
   • Manually - As inspiratory capacity increases, the therapist can apply manual resistance while the patient breathes deeply. If the intercostal musculature is functional, the therapist can provide manual, visual, or verbal feedback on chest motions during inspiration to increase the ventilation of isolated lobes.
   • Positioning - Since resistance to the diaphragm provided by abdominal contents increases in the head-down position, resistive strengthening can be achieved by changing the patient's position. For example, a 15-degrees head-down incline supplies a resistive force equal to 10 pounds.
   • Incentive Spirometry - After placing the patient in the preferable supine position (the weaker the diaphragm, the greater the necessary incline), the therapist has the patient take 4 slow, easy breaths. Expiration after the first 3 breaths should be normal, but, after the 4th breath, the patient should exhale slowly until there is no more air to exhale. The patient then places the spirometer in the mouth, forms a tight seal, takes a slow, deep breath, watches the ball in the spirometer rise, maintains the rise as long as possible, removes the spirometer mouthpiece, and relaxes. This should be repeated 8-10 times and done during 3-4 sessions each day.

2. Active-Assistive Exercises are done with active-assistive devices, such as pneumobelts and corsets, after the patient with poor diaphragm strength begins to sit.
   • Pneumobelts - Also called exhalation belts, pneumobelts are used for patients with an initial vital capacity between 500 and 1000 cc in an upright position. They have inflatable bladders, placed over the abdomen, and connected, with a hose, to an easily adjustable positive pressure respirator. As the bladder is inflated, it pushes the abdominal contents in and up, which push the diaphragm into the optimal position for exhalation. When the patient has been upright and on an active program for 8 hours, with no signs of fatigue and/or sternocleidomastoid muscle substitution, the patient can begin to be phased off the pneumobelt, by decreasing the pressure in the bladder, first while the patient is inactive, and then while he/she is active.
   • Corsets - Corsets are used for patients with weak, or "less than fair" abdominal musculature, whose diaphragms therefore are in a descended position, which causes a decrease in inspiratory reserve volume. Corsets are placed just over the last two floating ribs and covering the iliac crest. They should be snug (but not too tight) to support the abdomen and displace the diaphragm to a higher resting position, with the lower buckles tighter than the upper ones. A hand should be able to be placed under the upper part of the corset. Blood pressure and heart rate should be carefully monitored for hypotension and blood pooling. If diaphragm strength improves or abdominal tone increases enough to adequately support the abdominal contents, the corset can be discontinued after the patient's vital capacity, breathing pattern, and vital signs (with the body positioned at a 45 degree incline and the head up) test the same with, and without, the corset.