Technical cues - (1) Keep sit back like sitting in a chair (2) chest upright (3) More knees than hips.

Muscles worked - Quadriceps, hamstrings and gluteus maximus.

1. Video yourself performing the following movement patterns:

   • Provide two versions for each movement: one assisted/bodyweight and one weighted.

   • Record both front and side views in the video.

2. In each video, you must:

   • Identify the concentric, eccentric, and amortization phases.

   • Name the major muscles targeted.

   • Provide two technical cues.

   • Demonstrate correct technique.

Examples (to be explained in your video, not written):

1. Concentric, Eccentric, and Amortization Phases:

   • "During the squat, the eccentric phase occurs as you lower down, the amortization phase is the brief pause at the bottom, and the concentric phase is when you push back up to standing."

2. Major Muscles Targeted:

   • "In the push-up, the primary muscles worked include the chest (pectorals), triceps, and shoulders."

3. Technical Cues:

   • "For the deadlift: Keep your back straight and drive through your heels to lift the weight."

4. Demonstrate Correct Technique:

   • "In the lunge, ensure your knees track over your toes and maintain a neutral spine throughout the movement."

     
     

1. 录制自己完成以下运动模式的视频：

   • 每个运动提供两种版本：一种为辅助/自重版本，另一种为负重版本。

   • 录制视频时，请提供正面和侧面视角。

2. 在每个视频中，你必须：

   • 说明向心、离心和弹性三个阶段。

   • 说明主要目标肌肉。

   • 提供两个技术提示。

   • 展示正确的技术。

示例（这些内容必须在视频中解释，而不是书面形式）：

1. 向心、离心和弹性阶段：

   • “在深蹲时，离心阶段是你下降的过程，弹性阶段是在底部的短暂停顿，向心阶段是你重新站起时的过程。”

2. 主要目标肌肉：

   • “在俯卧撑中，主要锻炼的肌肉包括胸肌（胸大肌）、肱三头肌和肩部。”

3. 技术提示：

   • “对于硬拉：保持背部挺直，通过脚跟发力抬起重量。”

4. 展示正确技术：

   • “在弓步时，确保你的膝盖与脚趾对齐，并始终保持脊柱中立。”

Quadriceps: the main muscle on the front of the thigh.

Gluteus major muscle: the main muscle of the buttocks.

Posterior leg muscle group: including the cord muscle on the back of the leg.

Adcorctor muscle: the muscle of the inner thigh.

Calf muscles: the fibula muscle and flounder muscle of the calf.

Core muscle group: including abdominal and back muscles, which help maintain stability.

Preparation stage (equilength contraction):

Before starting to squat, the body is in a stationary state, and the muscles maintain tension and are ready to use force.

Squatting stage (centrifugal contraction):

The knee and hip joints begin to bend from the standing position, and the body gradually descends. This stage is centrifugal contraction, because the muscles are lengthened at the same time.

The centrifugal contraction stage is the most critical in squats, which establishes a strength foundation for the next centripetal contraction stage.

At this stage, the muscles slowly counter gravity under control to avoid injuries caused by rapid falls.

Bottom pause (equilength contraction):

When the thigh is parallel to the ground or lower, it usually pauses slightly at the bottom. This stage is isolength contraction, and the muscle length remains unchanged but the tension is maintained.

Squatting stage (centrimal contraction):

Starting from the bottom, push the body back to the initial standing position through the centripetal contraction of the leg and hip muscles.

The centripetal contraction stage requires muscle force to overcome gravity and push the body up.

Peak contraction (equilength contraction):

When the fully standing position is reached, the muscles are contracted again. At this time, the muscle length remains unchanged, but the maximum tension will be maintained for a short time to enhance the stability and strength of the muscles.

- [ ] Movement essentials: feet are the same width as the shoulders, the body is slightly tilted forward, and the elastic belt is held in both hands to do the rowing movement. This movement is divided into two parts: upper and lower. When doing the movement, we need to lower the waist while keeping our body straight and arms straight.

1. The feet are the same width as the shoulders, and the knees are slightly bent.

Two. Keep your back straight, keep your spine in a neutral position, and don't bend or arch your back.

3. Push your hips back and lean forward with your upper body. Imagine your hips sitting back while keeping your knees still.

Four. When your upper body is close to parallel to the ground, keep your back straight, and then push your body back to the starting position through the contraction force of the buttocks and posterior thigh muscles.