Qual ângulo mais intenso na Elevação Lateral? - Torque na Musculação #2

Summary

In this video, the focus is on understanding torque in muscle training, specifically in resistance training. The instructor explains the concept of torque, highlighting its role in generating rotational force around joints. Using the lateral raise exercise as an example, the script explores the relationship between force, resistance, and muscle effort. The video delves into how torque varies with angles during the exercise, emphasizing how the length of the lever arm (distance from the joint to the weight) impacts the intensity of the workout. Viewers are encouraged to experiment and analyze how torque affects their own training for better muscle engagement.

Takeaways

• 😀 Torque is a rotational force that depends on an axis and is essential in understanding human movement, especially in exercises like lateral raises.
• 😀 The experiment from last week explored the concept of torque in the context of muscle leverage and resistance, using weights in a physical exercise setting.
• 😀 The shoulder joint's anatomical movements, including abduction and adduction, are examples of rotational movements that torque helps explain.
• 😀 Torque is produced when a force is applied at a distance from an axis of rotation, and the force’s distance must be perpendicular to the axis to create torque.
• 😀 In exercises like lateral raises, the axis of rotation is located in the shoulder joint, with the deltoid muscle being responsible for abduction.
• 😀 The resistance force (weight) applied during lateral raises creates an opposing torque, which is key in understanding muscle activation during exercise.
• 😀 The concept of the lever arm or moment arm is crucial in torque calculations, with the length of the arm changing as the angle of the exercise movement changes.
• 😀 As the angle of the arm during lateral raises increases, the distance from the axis of rotation increases, which results in a larger torque and higher muscular effort.
• 😀 The greatest muscle effort and torque occur at the 90° angle of abduction, where the arm’s lever arm is at its longest and the resistance torque is highest.
• 😀 The video explores the interaction between the torque generated by muscles (muscle torque) and the resistance (resistive torque), demonstrating how these forces influence muscle fatigue and effort in exercises.

Q & A

What is torque, and how does it apply to the exercise demonstrated in the video?

Torque is a force that generates rotational movement around an axis. In the video, the concept of torque is applied to the human body during exercises like lateral raises, where the deltoid muscles produce a motor torque while lifting a weight, and the gravitational force on the weight produces a resistive torque.

How is the axis of rotation defined in the lateral raise exercise?

The axis of rotation in the lateral raise exercise is an imaginary line running from front to back of the body (anteroposterior axis) that allows the shoulder joint to perform the rotational movement (abduction and adduction) during the exercise.

What role do the deltoid and supraspinatus muscles play in the lateral raise?

The deltoid, particularly the middle (medial) part, and the supraspinatus muscle, which is part of the rotator cuff, are the primary muscles responsible for the abduction of the arm. These muscles generate the motor torque during the movement of lifting the weight in the lateral raise.

Why is understanding the concept of torque important in strength training?

Understanding torque helps to better grasp the mechanics of strength training exercises. By analyzing how torque is generated, trainers can optimize exercise techniques, improve performance, and minimize the risk of injury by understanding how forces interact with body movements.

How does the force of gravity affect the resistance during the lateral raise?

The force of gravity pulls the weight downward, creating a resistive torque. This resistive force acts vertically downward, and its intensity depends on the weight being lifted and the distance from the axis of rotation (shoulder joint).

What is the significance of the arm's position in determining the torque during the exercise?

The position of the arm significantly affects the torque experienced during the exercise. As the arm abducts, the lever arm (the distance from the axis to the point of application of force) increases, which increases the torque. The torque is greatest when the arm reaches 90 degrees of abduction, as this position maximizes the distance from the axis to the weight.

What does the 'arm of leverage' (braço de alavanca) refer to in the context of this exercise?

The 'arm of leverage' refers to the distance between the axis of rotation (the shoulder joint) and the point where the resistive force (the weight) is applied. This distance affects the amount of torque generated by the resistive force. A longer arm of leverage increases the torque, making the exercise more challenging.

How does the angle of the arm affect the intensity of the deltoid contraction?

The intensity of the deltoid contraction is higher when the arm is at an angle closer to 90 degrees of abduction because this position generates the greatest torque. At smaller or larger angles, the torque is lower, leading to less intensity in the deltoid contraction.

What is the key takeaway regarding the resistance torque during the lateral raise?

The key takeaway is that as the arm abducts, the 'arm of leverage' increases, which increases the torque resistive force. The greatest resistive torque occurs at around 90 degrees of abduction, making this position the most demanding for the deltoid.

How does the concept of torque differ when using free weights versus cables?

When using free weights, the resistance force is always vertical (due to gravity). However, when using cables, the angle of resistance changes based on the direction of the cable, which affects the arm of leverage and torque. This difference in resistance direction changes how the torque is applied and experienced during the exercise.