O controle dos movimentos voluntarios do ombro em nadadores com instabilidade glenoumeral

AUTOR(ES)
DATA DE PUBLICAÇÃO

2001

RESUMO

The Shoulder Impingement Syndrome (SIS) is often observed in repetitive movements of the shoulder above 60° during the performance of occupational or athletic activities. This dysfunction affects a great number of athletes, and in special 80% of the professional swimmers. In this population the glenohumeral instability is frequently associated with this syndrome. The purpose of this investigation was to analyze possible deficits of the motor control in the subjects with History of Shoulder Impingement Syndrome and Instability when compared with Normal subjects, in this way can provide better basis for evaluation of pathology. Methods. Eight swimmers without any neurological or orthopedic disorder (NN) and history of pain in the shoulder, and eight swimmers with (HSIS) took part in this experiment. Each subject performed bilateral and simultaneous elevation movements of the shoulder, "as fast as possible" in the scapular plane into three different target distances (30°, 90°, and 150° ). The Angle, velocity and acceleration , such as EMG muscle activities of the shoulder joint were recorded. The musc1es available were anterior deltoid, pectoralis major, latissimus dorsi from the glenohumeral joint and the scapulothoracic joint musc1es were serratus anterior, upper and lower trapezius. The biceps and triceps long head musc1es also were recorded. Results. The angular excursion and the angular velocity increase with distance for both groups of the subjects. The linear translational movements of the shoulder did not varied between groups for each of the three directions analyzed. However, the shoulder linear translation at each of the three direction increased with target distances. The intensity, in which each of the agonist musc1e of the glenohumeral an scapularthoracic joints were activated did not change with the target distances, and were similar for both groups of subjects. The amount of musc1e activities of the agonist and antagonist muscles increased with target distance, the only exception was for the amount of musc1e activity of the lower trapezius that did not increase with target distances. The two way ANOVA did not showed significant difference between two groups. The antagonist latency did not moduleted for three distances analized in the both groups. A despite of the recruitment ordem, all muscles of the two groups had the same time of the activation. Conclusion and Discussion. Compared with normal individuals, the swimmers with HSIS performed these movements with similar amplitude of movement and velocity and accuracy. The movements of the scapula was not affected by the movements of the humerus and vice-versa, contrary the any studies (Lukasiewicz, et al, 1999; Ludewig &Cook, 2000). Both groups of subjects used similar strategies to modula te the activities of the agonist and antagonist musc1es using the same rules of modulation that were described as "Speed Insensitivity Strategy" (Gotllieb, et al, 1989). So we can conclude that the history of shoulder impingement and/or the presence of shoulder instability did not affect the ability of the motor control system to activate and modulate the glenohumeral and scapulotoracic muscles to generate unloaded voluntary fast movements at the shoulder joint

ASSUNTO(S)

nadadores ombro

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