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Part A of Assessment 3: Exercise Library Creation

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."

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Exercise phases - The eccentric phase is the lowering phase of the squat where the muscle lengthens. The concentric phase is the standing up phase where the muscles shorten. The amotization phase is the one the transition between the lowering and standing phase.

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.

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第三部分 A：运动库创建

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第三部分 A：运动库创建

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。”

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This is the simple version. In knee push-ups, the body's descent stage is eccentric movement, and the body's ascent stage is concentric movement. The main muscles involved in concentric movement are the pectoralis major, anterior deltoid, and triceps brachii. These muscles contract and exert force to prop up the body. During eccentric movement, these same muscles are elongated to control the slow descent of the body. During the exercise, keep both knees on the ground, place both hands on the ground slightly wider than shoulder-width apart, and maintain a straight line from head to knees. Bend the elbows and slowly lower the body, then straighten the arms to prop up the body.

In a kneeling push-up, the body's descent phase is centrifugal, and the body's ascent phase is centripetal.

The main muscles that do the centripetal movement are the pectoralis major, the deltoid anterior bundle, and the triceps, which contract to lift the body up. During centrifugal exercise, these same muscles are elongated to control the body's slow descent.

Action points: Kneel on your legs, hands slightly wider than shoulder support, keeping a straight line from head to knee. Bend your elbows and slowly lower yourself, then straighten your arms and lift yourself up.

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In a kneeling push-up, the body's descent phase is centrifugal, and the body's ascent phase is centripetal.

The main muscles that do the centripetal movement are the pectoralis major, the deltoid anterior bundle, and the triceps, which contract to lift the body up. During centrifugal exercise, these same muscles are elongated to control the body's slow descent.

Action points: Kneel on your legs, hands slightly wider than shoulder support, keeping a straight line from head to knee. Bend your elbows and slowly lower yourself, then straighten your arms and lift yourself up.

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This is a simplified version of seated rowing. Centripetal movement is pulling the instrument towards the body. When sitting on the rowing machine, retract the shoulder blades, and the back muscles (latissimus dorsi, trapezius muscle, etc.) contract to pull the rod close to the abdomen or chest. The muscles shorten and the main back muscles generate force. Centrifugal movement is returning the instrument to the starting position. After centripetal movement, control the arm and back muscles to return the rod. The muscles are stretched. Controlling the speed and feeling the muscle stretch is very important for flexibility, muscle growth and muscle control. During the exercise, be slow and avoid relying on inertia. At the same time, keep the back straight and tighten the core.

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In gym machine rowing, centripetal movement is pulling the instrument to the body. Sitting on the rowing machine, shoulder blades retreat and back muscles contract to pull the rod near abdomen or chest. Muscles shorten and main back muscles generate force. Centrifugal movement is returning the instrument to starting position. After centripetal movement, control arm and back muscles to return rod. Muscles are stretched. Controlling speed and feeling muscle stretch is important for flexibility, growth and control.The muscles mainly exercised by seated rowing are: latissimus dorsi, middle and lower bundles of trapezius muscle, rhomboid muscle, biceps brachii, etc. Put your feet on the pedals, bend your knees slightly, lean forward slightly but keep your back straight. Retract your shoulder blades, use the back muscles to pull the handle towards the abdomen. When pulled to the maximum extent, pause for a moment and feel the contraction of the back muscles.

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This is the simple version of the movement, in the vertical push action, usually the upward push stage, the upper limb muscles (such as triceps, etc.) contract force, so that the arm is extended upward, at this time with the direction of the arm movement in the same muscle part of the centripetal movement; In the downward reduction stage, the muscles gradually relax, the arm falls under the action of gravity, and the muscle part that is opposite to the direction of the arm movement does centrifugal movement. The muscles used are the deltoids and triceps. Focus on keeping your core tight and your back straight during this exercise. Keep your elbows slightly forward and don't extend your head

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This is an upgraded version of the action, in the process usually push up the stage, the upper limb muscles contract force, so that the arm extended upward, at this time with the arm movement direction of the same muscle part to do centripetal movement; In the downward reduction stage, the muscles gradually relax, the arm falls under the action of gravity, and the muscle part that is opposite to the direction of the arm movement does centrifugal movement. The muscles used are the deltoids and triceps. Focus on keeping your core tight and your back straight during this exercise. Keep your elbows slightly forward and don't extend your head

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This is a simple pull-down. Although it looks similar to the simple version of push-up, there are still differences. In pull-down exercises, actively contracting muscles usually do concentric movements. Muscles like the biceps and latissimus dorsi that contract actively to pull the body up are doing concentric movements. In this process, the opposing muscles are elongated and do eccentric movements. For example, the muscles responsible for straightening the arms and lifting the body (such as the triceps) in pull-up and lowering exercises do eccentric movements. During the exercise, keep the back straight and chest up, avoid shrugging, and pull the elbows above the body.

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This is an advanced action.In a pull-down exercise, the muscles that are actively contracting are usually doing the centripital exercise. For example, in a pull-up exercise, the muscles that are actively contracting to pull the body up, such as the biceps and lats, are doing the centripital exercise.

The opposing muscles are elongated in this process and centrifuged, such as those responsible for straightening the arms and lifting the body (such as the triceps) in a pull-up and down exercise.Keep your back straight and your chest straight, avoid hunching your shoulders and pulling your elbows above your body

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Centripetal movement: The process of bending down to lift the bar from the ground until the body stands up straight.

Centrifugal exercise: The process of slowly lowering the barbell back to the ground from a standing position. Main: gluteus maximus, hamstring muscle, erector ridge muscle. Auxiliary: quadriceps, forearm muscle group, trapezius middle and lower bundle. Stand with your feet shoulder-width apart, toes slightly extended, the barbell is placed directly above the center of your feet, hold the bar with both hands, straighten your chest, pull your shoulder blades back, and lift your head slightly.

Pull up: bend the hips and bend the knees to hold the bar, start the gluteus maximus and hamstring muscles, extend the hips and knees to pull the barbell to stand straight, keeping the barbell close to the body.

Stand up straight with your chest pulled in and your spine neutral. Lower: Lower the barbell and feel the centrifugal contraction of the gluteus maximus and hamstrings.

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In the load-bearing version, the process of pulling the weight from the ground to the body standing straight is centripetal movement; The process of slowly lowering the weight from the standing position to the ground is centrifugal movement.

The main muscles used are gluteus maximus, hamstrings (biceps femoris, semitendinosus, semimememes), erector spinalis (core muscles of the lower back) and so on. At the same time, the quadriceps muscle in the front of the thigh will also play a certain stabilizing role.

1. Starting position: Feet shoulder-width apart, toes slightly extended, barbell in front of feet. Bend your knees and hold the bar with your hands slightly wider than your shoulders. Keep your back straight and your core tight. Pull up process: Pull the bar up from the floor by stretching your hips (pushing your hips back and forward) and extending your knees, keeping your back straight and the bar close to your body. Peak contractions: With the body standing straight and the bar on the front of the thigh, hold for 1-2 seconds and feel the contraction of the hips and hamstrings. Drop process: Slow and controlled drop the barbell, feel the centrifugal contraction, avoid sudden unloading and free fall of the barbell.

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This is a simple version of lunge. In lunge, the forward leg squat is a centrifugal motion, mainly the front and back of the thigh muscles are elongated to control the body descent; This is a centripetal movement in which the muscles of the thighs and hips contract to return the body to its starting position. The exercise uses the gluteus maximus, gluteus medius, quadriceps and hamstrings. In the process of exercise, the front foot heel first, and then the ball of the foot, kneeling down, the thigh as far as possible parallel to the ground, the calf is perpendicular to the ground, the back knee as close to the ground but do not touch. Keep your weight between your feet and your upper body straight. Don't lean forward or back. Push off with your front legs and push your body up while stepping forward with your back legs.

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Lunge walking in the forward leg center of gravity drop stage is centrifugal movement, backward leg center of gravity rise stage is centripetal movement. Stand with your feet together and your hands on your hips. Take a step forward, bend your front leg to about 90 degrees, straighten your back leg, and sink your weight. Then push your back leg up, pull your front leg back, and repeat on the other side. During the process, the body is kept stable and the core is tightened. The exercise uses the gluteus maximus, gluteus medius, quadriceps and hamstrings

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This is a simple version of the squat. During the squat, when the body is squatting down from the standing position, the quadriceps muscles in the front of the thighs, the hamstrings in the back and the gluteus maximus in the buttocks are elongated. These muscles perform centrifugal movements to control the body's slow descent. When standing up from a lower squat, the quadriceps, hamstrings, and gluteus maximus actively contract and shorten in length, and these muscles make centriolar movements to lift the body against body gravity. During this process, keep your feet shoulder-width apart, your back straight, your core tight, and your knees unbuttoned

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During squats, the main muscle groups are the quadriceps in the front of the thighs, the hamstrings in the back, and the gluteus maximus in the buttocks. When the body is squatting down from the standing position, the quadriceps, hamstrings and gluteus maximus are stretched, and these muscles do centrifugal movements to control the body's slow descent and avoid falling too fast and injury. When standing up from a lower squat, the quadriceps, hamstrings, and gluteus maximus actively contract and shorten in length. At this time, these muscles do a centriolar motion to lift the body upward against the body's gravity. Do this with your feet shoulder-width apart, your core tight, and your back straight.

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In the concentric movement stage when the body turns to one side, it is mainly completed by the contraction and exertion of the oblique abdominal muscles. When the body turns back to the middle position from one side or turns to the other side, the oblique abdominal muscles are elongated. At this time, it is eccentric movement.

Action points: Sit on the ground, bend the knees and lift the legs, with the feet off the ground. Tilt the body backward about 45 degrees. Hold a weight (such as a dumbbell) with both hands and keep the arms straight. Turn the body and move the weight from one side to the other. At the same time, keep the body stable and do not shake. The turning amplitude should be as large as possible, but pay attention to avoiding waist injuries.

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In the weight-bearing version of the Russian twist, the side rotation phase of the body is a centripetal movement, which is mainly completed by the contraction of the obliquus muscle. When the body rotates from one side back to the middle position or to the other side, the obliques are elongated, and this is a centrifugal movement.

Action points: Sit on the ground, knees raised, feet off the ground, leaning back about 45 degrees. Hold a weight (such as a dumbbell) with both hands and keep your arms straight. Turn your body and move the load from side to side while keeping your body steady and not swaying. Rotate as much as possible, but be careful to avoid waist injury.