Muscular fatigue, maximum strength an stress reactions of the shoulder musculature in paraplegics

In paraplegic patients, shoulder complaints attributable to muscle dysbalan ces arising from the particular daily form of exercise are often observed. The goal of therapy is to correct these imbalances through muscular trainin g, whereby eccentric exercise might offer advantages due to lower fatigue w ith concurrent higher maximum strength. This study therefore examines muscl e fatigue, maximum strength, and suitability for paraplegics of eccentric e xercise of the shoulder. Muscle fatigue, isokinetic peak torque, and EMG ac tivity were determined eccentric (Ecc) and concentric (Con) in 41 paraplegi c subjects (13 early rehabilitants; 16 trained in wheelchair sports; 12 unt rained). Serum CK, myoglobin, and subjective pain were collected for one we ek after exercise. In eccentric exercise, there was less muscle fatigue in all groups. Highest Ecc/Con peak torque ratio was found in trained subjects in all movements, followed by the untrained and the early rehabilitants. E MG-activity was lower in eccentric compared to concentric exercise (Ecc/Con ratio <1). CK and myoglobin concentrations, like pain symptoms, showed a m arked increase after exercise. It is concluded that the Ecc/Con strength pa tterns among paraplegics are altered. Eccentric exercise offers advantages on the basis of lower muscular fatigue independent of training status and l esion time and higher maximum strength with increasing duration of parapleg ia and additional athletic training. However, due to structural damage and subjective pain eccentric exercise can only be recommended with reservation s in therapy and training.