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

Abstract

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 do torque de resistência e da força muscular resultante durante exercício de extensão de quadril no Pilates e suas implicações na prescrição e progressão

“…In spite of the limitations from this approach, described on the methodological section of the present study, previous studies, not related to Pilates, showed that a mechanical analysis of the external demand offered by an exercises and the estimative of the resultant muscle effort made from biomechanical techniques, as a representation of the acting strengths through FBD and the use of movement equations, can be used objectively for the prescription of exercises during training and rehabilitation programs [11][12][13][14][15][16] . The analysis and investigation of the biomechanics of Pilates exercises gained great value, given the wide spread of this modality in clinical practice.…”

“…When HE is performed with the subjects positioned in supine on the equipment, the external load is obtained mainly from the external springs with different constants of strain and from the variation of the equipment's spring vertical regulation ( fixed height) 10 . In genneral, it has been recommended that rehabilitation programs use the exercises with progressive intensities according to the necessities of each patient [11][12] . However, when Pilates' exercises are used in clinical practice, it is observed that the external loads are chosen based on subjective information, such as the substitution of a less resistent spring to another with higher resistance, without noticing the amount of resistance offered in both situations 10 .…”

“…The reason for this is that the sping's strength (given by the constant of strain and the variation of its length) in addition to its respective perpendicular distance (directly determined by the fixation site of the spring) compose the resistance torque (T R ) offered by this exercise, during the exercise range of motion (ROM). Thus, in clinical practice, Γ R assessment (which considers the variations in the constant of strain and the fixation height of the spring) may provide useful quantitative data for progressing the intensity of the program over the course of the treatment and also indicate in which joint position the external load is maximum 11,[13][14][15] , allowing clinicians to prioritize strength gains in specific ranges of motion.…”

Comparative study between two elbow flexion exercises using the estimated resultant muscle force

“…These variations produce differentiated external resistance, and consequently require distinct muscle efforts in each case. Although the organization of different activation strategies for muscle groups is highly complex and is not fully understood 16 , mechanical analysis has recently been used to understand exercises 10 , and even to choose one exercise over another 17,18 . Hence, in an attempt to understand the elbow flexion exercise from a mechanical perspective, the objective of the present study was to compare the estimated resultant muscle force required throughout the full ROM in two distinct elbow flexion exercises.…”

Modelo para estimativa da força e torque muscular durante a abdução do ombro

“…Alguns estudos dedicaram-se a identificar o grau de envolvimento de cada músculo no gesto analisado durante rotações internas e externas do ombro (5,7,11,29) . Outros voltaram-se para a análise das forças musculares resultantes durante os movimentos referidos (17,30,31) . Muitos estudos mediram a magnitude do braço de alavanca de abdução dos músculos do ombro (12,18,21,27) .…”