Daniel Cury Ribeiro

Critérios mecânicos para progressão de exercícios de rotação interna e externa do ombro no plano sagital

Introduction: Knowledge of torque and force production capacity and moment arm patterns throughout the movement, and their influence on the torque produced, are essential for understanding human movement and may be of great use for controlling the overload imposed on the muscle-tendon structure. Objective: To present mechanical criteria for progression in internal rotation (IR) and external rotation (ER) exercises of the shoulder in the sagittal plane. Method: Six individuals were assessed using an isokinetic dynamometer and an electrogoniometer. From the data collected, the mean torque, mean resultant force and weighted mean moment arm were calculated using the SAD32 and Matlab ® software. Results: The angles at which the peak ER and IR torque occurred were -34° and 6o with values of 43 Nm and 69 Nm, respectively. The peaks for ER and IR muscle force were at 35o and -14o, and the values at these angles were 10227 N and 8464 N, respectively. The weighted mean moment arm for ER presented an increasing pattern over the whole range of motion (ROM) and the peak was at the end of the ROM, i.e. at -50o (0.91 cm). The weighted mean moment arm for IR was almost constant with its peak at 50o (0.96 cm). Conclusion: The mechanical criteria for progression in internal and external rotation exercises of the shoulder are torque, force and weighted mean moment arm because different overloads on the muscle-tendon structure can be caused according to their patterns over the ROM.

Análise por dinâmica inversa, um complemento da avaliação fisioterapêutica do ombro

The purpose of this study was to describe forces acting on the shoulder joint during upper limb elevation at the scapular plane by means of the inverse dynamics method, here suggested as a complementary means of physiotherapeutic assessment of the shoulder. The method allows for determining proximal net moment (PNM) and proximal net force (PNF) peaks during movements, hence providing an objective assessment of loads on the joint. Twenty-one male subjects were studied, their shoulder movements being analysed by videogrammetry in three load situations: with and without load, and with elastic resistance. A three-dimensional mathematic model was used to calculate PNM and PNF peak values, as well as to describe their evolution during movement along the anterior-posterior, superior-inferior, and lateral-medial axes. The inverse dynamics method was thus shown to provide objective information on the loads which shoulder joint is submitted to at the diverse ranges of motion and load situations during arm elevation; such information may be taken as a factual basis for planning shoulder rehabilitation programs.