Inspiratory muscle training in quadriplegic patients

To determine whether inspiratory muscle training can increase strength and endurance of these muscles in quadriplegic patients.

Eight quadriplegic patients (7 males and 1 female) with injury to the lower cervical spine (segments C4-C7) were submitted to inspiratory muscle training with a threshold inspiratory muscle trainer adjusted to 30% of MIP. The training sessions were carried out with the patients in a sitting position, 5 days a week for 8 weeks. Endurance time, MIP, MEP and FVC were determined at baseline, week 4 and week 8.

In comparison with the mean baseline value, there was an increase in MIP, measured in the sitting position, at weeks 4 and 8 (-83.0 +/- 18.9 cmH2O vs. -104.0 +/- 19.4 cmH2O and -111.3 +/- 22.7 cmH2O). There was an increase in MEP, also in the sitting position, at week 4 (from 36.8 +/- 8.1 to 42.6 +/- 8.8 cmH2O). There was an improvement in FVC at week 4 (from 2.1 +/- 0.8 to 2.5 +/- 0.6 L, representing an increase of 24 +/- 22%). Although there was an increase in endurance (sitting) at week 8, the difference was not significant in comparison with the baseline value (29.8 +/- 21.0 vs. 35.9 +/- 15.5 min, an increase of 173 +/- 233%).

Quadriplegic patients can benefit from training at low loads (30% of MIP), which can improve inspiratory muscle strength, FVC and expiratory muscle performance.