Arm Scissors
| English Name | Arm Scissors |
|---|---|
| Difficulty | Beginner |
| Movement Patterns | Gait / Locomotion |
| Muscle Contraction Types | Isotonic |
| Primary Muscle (EN) | Anterior & Lateral Deltoid |
| Muscle Groups | Chest muscles Shoulder Muscles |
|---|---|
| Workout Type | Corrective Recovery Stretching |
| Required equipment | No equipment |
💠 Exercise guide
✅ Arm Scissors is a dynamic, rhythmic exercise performed by opening and closing the arms in a scissor-like motion in front of the body. Its main purpose is to prepare the shoulders and chest for pressing movements, improve scapular control, increase blood flow, and reduce stiffness in the front of the shoulders. This exercise is highly effective for warm-ups, recovery, and postural correction (reducing rounded shoulders).
💠 Execution Guide
Setup
✅ Stand tall; feet hip-width apart, knees soft and not locked.
✅ Neutral spine; chest “up but ribs down” (no lower-back arch).
✅ Open the arms at shoulder height (T position), elbows nearly straight but not locked.
✅ Keep the shoulder blades gently down and back (avoid shrugging).
✅ Calm, rhythmic breathing; take a few deep diaphragmatic breaths before starting.
Execution
✅ Start with the arms open out to the sides (T position).
✅ Bring the arms together in front of the chest and cross them over each other (like scissors), without jerking.
✅ As the arms cross, keep the elbows nearly straight and move from the shoulders—not the lower back.
✅ Immediately open the arms back out and return to the T position.
✅ On the next rep, switch which arm goes on top (one rep right over left, next rep left over right).
✅ Recommended rhythm: smooth and controlled (not too slow, not ballistic).
✅ Move through a range where you feel a chest stretch, but without pain or shoulder pinching.
Coaching Cues
✔️ Keep the arms close to shoulder height throughout the movement (dropping the arms reduces effectiveness).
✔️ Don’t shrug the shoulders; keep the neck long and imagine the shoulder blades “down in your pockets.”
✔️ Chest open but no lower-back arch; keep the ribs under control.
✔️ Keep the movement smooth; avoid swinging or sudden acceleration.
✔️ During the crossing phase, allow controlled scapular protraction—but don’t let the shoulders collapse forward.
✔️ As the arms open, let the shoulder blades return to gentle retraction (improves scapular control).
✔️ If you feel pinching in the front of the shoulder, reduce the crossing range and set the arm angle slightly below shoulder height.
✔️ Keep the core active so the body doesn’t rotate during the movement and the lower back doesn’t assist.
Benefits of the exercise
1️⃣ Increases warm-up and blood flow to the shoulder girdle before training
2️⃣ Improves horizontal shoulder mobility (Horizontal Adduction/Abduction)
3️⃣ Reduces stiffness in the chest and front of the shoulders (great for people with rounded shoulders)
4️⃣ Enhances controlled scapular movement (protraction/retraction)
5️⃣ Helps prepare for bench press, shoulder press, and push-ups
6️⃣ Improves neuromuscular coordination and scapulohumeral rhythm
7️⃣ Increases light endurance of the shoulder muscles during longer sets
8️⃣ Supports better posture and reduces neck tension when performed correctly
9️⃣ An excellent option for active recovery between upper-body sets
🔟 Can be performed anywhere, without equipment, and is ideal for a quick warm-up routine
Common Mistakes
❌ Incomplete, partial range of motion (no effective chest stretch)
❌ Shrugging the shoulders and excessive neck/upper-trap involvement
❌ Arching the lower back and flaring the ribs to compensate for range
❌ Excessive elbow bending, turning it into an “arm exercise” instead of a shoulder movement
❌ Performing the movement too fast or ballistically and losing scapular control
❌ Rotating the torso side to side (using the lower back due to weak core)
❌ Letting the arms drop below shoulder height (reduced deltoid targeting)
❌ Over-crossing the arms with pain or shoulder pinching (overstretch)
❌ Forward head and neck posture
Breathing Pattern
🌬️ Inhale: When the arms are open or opening back to the T position
💨 Exhale: When bringing the arms together and crossing them in front of the body
🔸 For warm-up and mobility, the Valsalva maneuver is not needed; breathing should be free and rhythmic.
⚠️ If the goal is more aerobic or higher-intensity warm-up: keep exhales short and regular, without breath-holding.
ROM Guidelines
🔵 Recommended range: Move the arms only to the point where you feel a stretch in the chest/front of the shoulder—without pain
🔵 Minimum acceptable range: hands touch or come close together in front of the chest + fully open back to the T position
🔵 Risky range: excessively deep crossing with front-shoulder pain, pinching, numbness, or tingling
Precautions & Contraindications
⚠️ Acute shoulder pain or inflammation (especially impingement or supraspinatus tendon issues)
⚠️ History of shoulder dislocation or instability (limit the range of motion)
⚠️ Acute neck pain or severe upper-trap trigger points (be extra mindful of keeping the shoulders down)
⚠️ If numbness in the arm or sharp, radiating pain occurs: stop the movement and reduce the range / seek professional evaluation
Variations & Alternatives
🔹 Easier version: smaller range + slower speed + 1-second pause in the T position
🔹 Advanced version: faster rhythmic speed or longer duration (45–60 seconds)
🔹 Limited equipment: light band around the wrists (adds tension during opening)
🔹 Alternatives for pain/limitations:
- Wall Angels
- Light Band Pull-Aparts (if there is no front-shoulder pain)
- Light Arm Circles
Advanced Biomechanics
🧠 The movement occurs primarily in the horizontal/transverse plane:
Bringing the arms together = Horizontal Adduction (assistance from the chest and anterior deltoid)
Opening the arms = Horizontal Abduction (assistance from the posterior deltoid, rhomboids, and mid-trapezius)
🧠 Scapular control is critical:
Closing = controlled protraction
Opening = gentle retraction without locking the shoulder blades
The higher the arms and the straighter the elbows, the greater the moment arm and the higher the demand on shoulder control.
Programming Tips
📌 General upper-body warm-up: 2–3 sets × 20–40 seconds (or 15–30 reps)
📌 Active recovery between sets: 1 set × 20–30 seconds at low intensity
📌 Mobility / corrective goal: 2 sets × 8–12 controlled reps with a short pause in the T position
📌 Recommended tempo: 1–0–1 (1 second in, no pause, 1 second out) or a steady rhythm
📌 Placement in the program: at the start of upper-body / pressing workouts, or as a corrective superset with back exercises
💠 Muscle Involvement
✅ Arm Scissors, by creating a back-and-forth arm motion in front of the body and returning to the T position, simultaneously engages the deltoids, chest, and scapular control muscles. The closing phase primarily activates the chest and anterior deltoid, while the opening phase places greater emphasis on the rear deltoid and scapular stabilizers; therefore, it is an excellent exercise for balancing the shoulder girdle and preparing the body before pressing movements.
Main muscles
Deltoid Muscle
Deltoideus Muscle
🔹 The deltoid muscle is one of the most important and voluminous muscles of the shoulder region. Its primary function is to move the arm in various directions and stabilize the shoulder joint. Due to its triangular shape, it is named “deltoid,” derived from the Greek word “Δέλτα” (delta), meaning triangle.
🔹 The deltoid muscle is divided into three distinct heads, each playing a specific role in shoulder movement. The anterior head assists in forward motions and arm flexion, the middle head is responsible for abduction and lifting the arm, and the posterior head supports extension and movements behind the body. This muscle is essential for the stability and strength of the shoulder joint, and its weakness can lead to limited range of motion, reduced shoulder power, and an increased risk of injury.
🖼️ Image Gallery
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🔷 Full Description
Click on the title to read the sections.
✅ Persian Name: Deltoeid
✅ Latin Name: Deltoideus
✅ Common Name: Shoulder Muscle
✅ Location:
🟡 A superficial muscle located at the top of the upper arm, covering the shoulder joint.
🟡 It forms a cap-like structure over the shoulder joint.
🟡 It directly overlays the head of the humerus and originates from the clavicle, scapula, and the upper part of the arm.
✅ 🔹 Origin
✔ Anterior part: from the outer surface of the clavicle
✔ Middle part: from the acromion, a portion of the scapula
✔ Posterior part: from the spine of the scapula
✅ 🔹 Insertion
✔ All parts of the deltoid muscle insert onto the deltoid tuberosity of the humerus.
✅ 🔹 Function
📌 The deltoid muscle is divided into three parts, each with a specific function:
1️⃣ Anterior Head
- ✔ Moving the arm forward (shoulder flexion)
- ✔ Internal rotation of the arm
- ✔ Assists in horizontal adduction of the arm (moving the arm forward across the body)
2️⃣ Middle Head
- ✔ Lifting the arm outward (shoulder abduction)
- ✔ Assists in stabilizing the shoulder during arm elevation
3️⃣ Posterior Head
- ✔ Moving the arm backward (shoulder extension)
- ✔ External rotation of the arm
- ✔ Assists in horizontal abduction of the arm (moving the arm backward across the body)
📌 Function Summary: The deltoid muscle plays a key role in all shoulder movements and is one of the primary muscles responsible for moving the arm in various directions.
✅ 💪🏻 Muscle Fiber Types
✔ The deltoid muscle consists of a combination of fiber types. ✔ A combination of slow-twitch fibers (Type I) and fast-twitch fibers (Type II). ✔ It is composed of both fiber types.
✔ The anterior and posterior heads contain more fast-twitch fibers, which are suited for powerful and rapid movements.
✔ The middle head has a higher proportion of slow-twitch fibers, which help maintain muscular endurance during sustained activity.
✅ 🏋🏻♂️ Role in Sports and Physical Activities
✔ Plays a key role in all overhead movements, such as shoulder press and bench press.
✔ Crucial for sports like weightlifting, swimming, gymnastics, and wrestling.
✔ Considered one of the primary muscles involved in carrying heavy objects, throwing, and raising the arm.
✅ 🧗🏻♂️ Strength and Endurance
✔ The deltoid plays a vital role in maintaining shoulder joint stability, and its weakness can reduce control over shoulder movements.
✔ This muscle is well-suited for both strength and endurance activities and is heavily engaged in many professional sports.
✅ 🧠 Innervation
✔ Axillary Nerve (also known as the underarm nerve) – responsible for controlling deltoid muscle movements and providing sensation to the shoulder area.
✅ 🩸 Blood Supply
✔ Posterior Circumflex Humeral Artery
✔ Thoracoacromial Artery
✅ 🤼♂️ Role in Sports and Physical Activities
✔ Directly involved in all shoulder and arm movements.
✔ A key muscle for athletes in bodybuilding, weightlifting, swimming, boxing, and combat sports.
✔ Strengthening this muscle improves shoulder shape, prevents injuries, and boosts upper body strength.
✅ 🏌🏻♂️ Interaction with Other Muscles and Joints
✔ Works closely with the rotator cuff muscles, back muscles, and pectoralis major.
✔ Weakness in this muscle can lead to excessive strain on the shoulder and scapular joints, increasing the risk of injury.
✅ 💉 Vulnerability and Potential Issues
✔ One of the most injury-prone muscles in bodybuilding and strength sports due to its crucial role in heavy movements.
✔ Common injuries include tears, strains, tendon inflammation, and cramps—often caused by improper use of heavy weights.
✅ 🏋🏻♂️ Strength Training Exercises for the Deltoid Muscle
1️⃣ Dumbbell or Barbell Shoulder Press – Strengthens all parts of the deltoid
2️⃣ Lateral Raise – Targets the middle head of the deltoid
3️⃣ Bent-Over Reverse Fly – Strengthens the posterior head of the deltoid
4️⃣ Front Raise with Dumbbell or Barbell – Focuses on the anterior head
5️⃣ Arnold Press – Activates all heads of the deltoid simultaneously
✅ 🧘🏻♀️ Stretching and Recovery
✔ Forward and backward shoulder stretches
✔ Wall walks with the hand to improve flexibility
✅ Fun Fact
✔ The deltoid muscle is actually one of the key muscles that shapes and enhances the appearance of the upper body.
✅ Practical Tip
✔ Overtraining the deltoid without strengthening the back and rotator cuff muscles can disrupt shoulder muscle balance.
🔴 Name and Location: A superficial muscle that covers the shoulder joint and originates from the clavicle, scapula, and humerus.
🟠 Anatomy: Composed of three parts—anterior, middle, and posterior—each responsible for different shoulder movements.
🟡 Function:
✔ Anterior: Arm flexion and internal rotation
✔ Middle: Arm abduction and elevation
✔ Posterior: Arm extension and external rotation
🟢 Physiology: A combination of slow- and fast-twitch fibers, allowing for both endurance and explosive power movements.
🔵 Innervation: Axillary nerve, which controls the muscle’s movement and sensation in the shoulder area.
🟣 Importance: Active in all upper-body movements, bodybuilding, weightlifting, swimming, boxing, and combat sports.
🟤 Exercises: Shoulder press, lateral raise, front raise, bent-over raise, Arnold press.
⚫ Fun Fact: A key muscle for shoulder strength and aesthetics, yet one of the most injury-prone muscles during heavy training.
💠 Other Exercises
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💠 Muscle Training
Pelank is a comprehensive encyclopedia of the body’s muscles, providing an accurate and scientific review of all muscles. Below, you can find muscle groups. By clicking on each muscle group, you will have access to complete information about it, including:
1️⃣ Basic information about the muscle
2️⃣ Muscle anatomy
3️⃣ Muscle physiology
4️⃣ Innervation and blood supply
5️⃣ Importance of the muscle in the body and sports
6️⃣ Strengthening exercises
7️⃣ Scientific and interesting facts
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