Study Design: Prospective study cohort describing lung function, exercise tolerance and strength inspiratory and expiratory muscles.

Objective: To analyze lung function and ventilatory response to exercise in adolescents with thoracic curves > 45, candidates to surgery.

Summary of background: Adolescents with symptomatic scoliosis have little or no impairment of resting lung volumes. We have limited information about moderates scoliosis. In some series not found abnormalities and in others ones report little restrictive pulmonary function and lower exercise tolerance. We have found no one study that it have valuated the strength of the respiratory muscles.

Methods: From 2002 until 2003. They were evaluated 19 patients with AIS (4 males and 15 females) who were indicated to surgical treatment. Mean age of 16 (13–26). The mean Cobb angle was 61 (45–105). Flow curves were obtained by maximal forced expirations. Incremental exercise was performed by cycloergometry using the protocol described by Neder et al. Muscle strength was measured by one system of valve with incremental weight.

Results: The mean values of spirometry were FEV 1 81 (+/−14% ref), %FEV 1/FVC 82 +/−6, TLC 86 +/− 11%ref, RV 106 +/− 20% ref. The strength of respiratory muscles was significant lower, Pimax. 67% (p=0’030), Pemax 65% (p< 0’0001). In the exercise capacity the VO2 max was significantly lower (54’5 % ref., p< 0’05) but without to be the VE max and the heart rate the restricted factor.

Conclusions:

The rest lung volumes are into the normal values but in the lower side.