Individuals with spinal cord injury (SCI) have frequent pulmonary complications, with impaired respiratory muscle strength and lung function.

To analyze the behavior of static and dynamic measures of inspiratory muscle strength in individuals with SCI after inspiratory muscle training (IMT).

Clinical, randomized, controlled trial, carried out at the Centro Estadual de Reabilitação e Readaptação Dr. Henrique Santillo (CRER), with individuals diagnosed with complete motor SCI, classified as having chronic quadriplegia, ASIA Impairment Scale (AIS) A or B, hospitalized for rehabilitation, from March 2020 to June 2021. Maximal inspiratory muscle pressure (MIP) was evaluated using manovacuometry and dynamic measurement of inspiratory muscle strength (S-Index) using the PowerBreathe K5. The subjects were randomized into blocks of six patients into three groups, two intervention groups, as follows: (Group I) care with conventional physiotherapy associated with low-pressure IMT (30% S-Index), (Group II) care with conventional physiotherapy associated with a specific IMT with high pressure (50% S-Index), and a control group (Group III) that received care with conventional physiotherapy. IMT was performed with the PowerBreathe K5 device, with load adjustment performed weekly and 10% increments based on the S-Index. The protocol consisted of 4 weeks of intervention, with training 5 times a week, 2 times a day. Parametric data were presented with mean and standard deviation and non-parametric data with median and 25th and 75th percentiles. Factorial and Friedman ANOVA were used for comparison between groups, and a significant value of p≤0.05 was adopted.

Partial data from 6 individuals with a mean age of 33±11.3 years, all male, mean height 1.75±0.08cm, Body Mass Index 73.3 ±19.9 kg/m2, with an average time of injury 28±17.4 months, 2(33.3%) with the neurological level of injury in C4, 2(33.3%) C5, 2 (33.3%) C6, 5 (83.3 %) classified as AIS A, 3 (50%) declared to be former smokers. Comparing MIP before and after IMT, we observed an increase in all groups, with predominance in group I (-60±14 vs -105±21cmH2O, p=0.18) followed by GII and GIII (-45±7 vs -57±3cmH2O, p=0.18; -80±0 vs -92±3cmH2O p=0.18, respectively) with no significant difference. The S-Index showed an increase in GI (79.5±38.39 vs - 112±38cmH2O, p=0.14) and GIII (107±57 vs - 180±149cmH2O, p=0.49) and a reduction in GII (193±55 vs - 166±159cmH2O, p=0.49) with no difference between groups.

The IMT seems to promote an increase in the static and dynamic inspiratory muscle forces, with a predominance in the training group with lower loads, however, we did not observe any difference in the inspiratory muscle forces with different loads in the IMT for the studied population.

The incipient data are still not enough.