Have you ever taken a moment to ponder which muscle lifts your arm out to the side? It’s one of those things that you probably don’t think about until you have a shoulder injury and you’re desperately trying to figure out how to rehab it. Well, the answer to that question is the lateral deltoid muscle. It’s one of the three heads that make up the deltoid muscle group, and it’s responsible for moving your arm away from your body to the side.
The lateral deltoid muscle is more commonly referred to as the middle head of the deltoid muscle group. It sits on the outer edge of your shoulder and is triangular in shape. This muscle attaches to your humerus bone and is responsible for lifting your arm out to the side. So, if you’ve ever tried to do a lateral raise with dumbbells, you know exactly which muscle is doing all the work. This muscle is crucial for performing a number of upper body exercises and is often targeted specifically in workouts for building broader shoulders.
Many people assume that the larger muscles in your chest and back are the only ones responsible for stabilizing and moving your arms during exercises. But if you’ve ever experienced shoulder pain or weakness, you know that this isn’t the case. The lateral deltoid muscle plays a crucial role in shoulder movement and stability, and it’s important to focus on strengthening it in order to prevent injury and improve athletic performance. So, next time you’re hitting the weights, don’t forget to give a little love to your lateral deltoids!
Shoulder Anatomy 101
The shoulder joint is one of the most complex joints in the body, capable of a wide range of motion. To understand what muscle lifts arm out to side, we’ll need to take a closer look at the shoulder anatomy.
- The shoulder comprises three main bones: the clavicle (collarbone), scapula (shoulder blade), and humerus (upper arm bone).
- The glenoid cavity is a shallow socket on the scapula that the humerus fits into, forming the ball-and-socket joint of the shoulder.
- The rotator cuff is a group of four muscles and their tendons that hold the humerus in the glenoid cavity and help stabilize and move the shoulder joint.
Now that we have an overview of the shoulder anatomy, let’s talk about the muscle that lifts the arm out to the side.
Deltoid Muscle
The deltoid muscle, also known as the deltoid or shoulder muscle, is a large, triangular muscle that covers the shoulder joint. It is responsible for lifting the arm out to the side (abduction) and extending the arm backwards (extension).
The deltoid muscle has three parts, or heads:
| Part | Location | Action |
|---|---|---|
| Anterior (front) | Clavicle | Flexes the arm at the shoulder joint and horizontally adducts the arm. |
| Medial (middle) | Scapula | Abducts the arm at the shoulder joint. |
| Posterior (back) | Spine of the scapula, acromion process | Extends the arm at the shoulder joint and horizontally abducts the arm. |
So, to answer the question of what muscle lifts arm out to the side, it’s the medial head of the deltoid muscle.
Muscles of the Shoulder Joint
The shoulder joint is one of the most mobile joints in the body, allowing for a wide range of movements including flexion, extension, abduction, adduction, internal rotation, and external rotation. There are several muscles that contribute to these movements, including the:
Rotator Cuff
- Supraspinatus
- Infraspinatus
- Teres Minor
- Subscapularis
The rotator cuff muscles are a group of four muscles that originate from the scapula and attach to the humerus. They work together to stabilize the shoulder joint and help to rotate the arm. The supraspinatus is responsible for initiating abduction of the arm, while the infraspinatus and teres minor externally rotate the arm. The subscapularis internally rotates the arm and also helps to adduct the arm.
Because the rotator cuff muscles are so important for the stability of the shoulder joint, they are commonly injured, especially in athletes who perform overhead activities such as baseball pitchers and tennis players. Rotator cuff injuries can range from mild inflammation to complete tears, and can be treated with rest, physical therapy, and in severe cases, surgery.
Deltoid
The deltoid muscle is a large muscle that covers the shoulder joint and is responsible for lifting the arm out to the side (abduction). It has three sections, known as the anterior, middle, and posterior deltoid, each of which contributes to different movements. The anterior deltoid assists with flexion and internal rotation of the arm, the middle deltoid is responsible for abduction of the arm, and the posterior deltoid assists with extension and external rotation of the arm.
| Deltoid Section | Origin | Insertion |
|---|---|---|
| Anterior | Clavicle | Deltoid tuberosity of humerus |
| Middle | Acromion | Deltoid tuberosity of humerus |
| Posterior | Spine of scapula | Deltoid tuberosity of humerus |
Training the deltoid muscles is important for both aesthetic and functional reasons. Strong deltoids can help to prevent shoulder injuries, as well as improve athletic performance in activities such as throwing and overhead lifting. Exercises such as shoulder presses, lateral raises, and upright rows can all help to develop the deltoid muscles.
Deltoid Muscle Function
The deltoid muscle, also known as the shoulder muscle, is a large muscle responsible for lifting the arm out to the side and rotating the arm up and down. It is located on the uppermost part of the arm and is comprised of three separate heads: the anterior (front), lateral (middle), and posterior (rear) deltoids. Each head has its own specific functions, but they work together to perform most shoulder movements.
- The anterior deltoid functions to lift the arm up and forward, such as during a shoulder press or front raise.
- The lateral deltoid is responsible for lifting the arm up to the side, such as during a lateral raise or lateral pull-down.
- The posterior deltoid primarily works to pull the arm backward, such as during a row or rear-delt fly.
These three heads of the deltoid muscle also work together to stabilize the shoulder joint during movements. When the rotator cuff muscles are fatigued or weak, the deltoid muscle helps to compensate and provide additional support to the shoulder joint.
In addition to its role in lifting and stabilizing the shoulder, the deltoid muscle is also involved in many upper body exercises such as push-ups, pull-ups, and bench presses. These exercises can help to strengthen the deltoid muscle and improve shoulder mobility and stability.
| Deltoid Head | Function | Exercise Examples |
|---|---|---|
| Anterior | Lifts the arm up and forward | Shoulder press, front raise |
| Lateral | Lifts the arm out to the side | Lateral raise, lateral pull-down |
| Posterior | Pulls the arm backwards | Row, rear-delt fly |
Overall, the deltoid muscle is an essential muscle for proper shoulder function and upper body strength. By incorporating exercises that target the different heads of the deltoid muscle, individuals can improve their shoulder mobility, stability, and overall upper body strength.
Rotator Cuff Muscles
The rotator cuff refers to a group of four muscles and tendons that connect your upper arm bone to your shoulder blade. These muscles are responsible for supporting and stabilizing the shoulder joint, as well as allowing for rotational movement of the arm. The four muscles that make up the rotator cuff are:
- Supraspinatus: This muscle is located on top of the shoulder blade and helps lift the arm out to the side.
- Infraspinatus: This muscle is located on the back of the shoulder blade and helps rotate the arm outward.
- Teres minor: This muscle is located on the back of the shoulder blade and helps rotate the arm outward.
- Subscapularis: This muscle is located on the front of the shoulder blade and helps rotate the arm inward.
While all four muscles are important for shoulder function, the supraspinatus is the most commonly injured rotator cuff muscle. This is because it passes through a narrow space between the shoulder blade and the collarbone, making it more prone to impingement and tears.
Rotator cuff injuries are common in athletes, particularly those involved in sports that require repetitive overhead movements, such as baseball, swimming, and tennis. However, they can also occur in individuals who perform tasks that require lifting or reaching overhead, such as construction workers or painters.
| Injury | Symptoms |
|---|---|
| Rotator cuff tear | Pain, weakness, limited range of motion, clicking or popping sounds |
| Rotator cuff impingement | Pain, tenderness, weakness, difficulty lifting the arm above shoulder height |
| Rotator cuff tendinitis | Pain and tenderness in the front of the shoulder, worsening with overhead activity |
If you suspect you have a rotator cuff injury, it is important to seek medical attention. Treatment may include rest, physical therapy, medication, or surgery, depending on the severity of the injury.
Strengthening Exercises for the Deltoid Muscle
If you’re looking to strengthen the deltoid muscle, there are a number of exercises that can help you achieve your goal. The deltoid, commonly referred to as the “shoulder muscle,” is located in the upper arm and is responsible for lifting your arm out to the side.
Top 5 Strengthening Exercises for the Deltoid Muscle
- Seated Dumbbell Press: This exercise targets the entire deltoid muscle and can be performed using a set of dumbbells while sitting on a bench or chair.
- Standing Military Press: This exercise focuses on the middle and front portions of the deltoid muscle and is a great way to build overall shoulder strength.
- Side Lateral Raise: This exercise specifically targets the side portion of the deltoid muscle and can be done using a set of dumbbells while standing or seated.
- Bent-Over Rear Delt Raise: This exercise targets the rear portion of the deltoid muscle and can be done using a set of dumbbells while standing or seated.
- Upright Row: This exercise targets the middle portion of the deltoid muscle and can be done using a barbell, dumbbells, or a cable machine.
Tips for Effective Deltoid Muscle Strengthening
When performing these exercises, it’s important to focus on form over weight. Use a weight that allows you to complete each movement with proper form and technique, and gradually increase the weight over time as your strength improves.
In addition to the exercises listed above, incorporating compound exercises that target multiple muscle groups (such as bench presses and pull-ups) can also help to strengthen the deltoid muscle.
Deltoid Muscle Anatomy
To better understand the deltoid muscle and how it functions, it’s helpful to take a closer look at its anatomy. The deltoid is a triangular-shaped muscle that originates on the clavicle and scapula and inserts on the humerus (upper arm bone).
| Deltoid Muscle Portion | Function |
|---|---|
| Anterior | Internal Rotation of the Arm, Shoulder Flexion |
| Middle | Abduction of the Arm, Shoulder Flexion |
| Posterior | External Rotation of the Arm, Shoulder Extension |
By incorporating these strengthening exercises into your routine and focusing on proper form, you can effectively target and strengthen all three portions of the deltoid muscle, leading to greater overall shoulder strength and stability.
Common Shoulder Injuries and Treatment
The shoulder is the most mobile joint in the human body and is often subject to injury or trauma from overuse, repetitive motion, and direct impact or falls. Here are some of the common shoulder injuries and their treatments.
Common Shoulder Injuries
- Rotator cuff tear: A tear in the tendons or muscles in the shoulder that can occur suddenly or over time due to repetitive overhead motion. Symptoms include pain, weakness, and limited range of motion. Treatment includes rest, physical therapy, and surgery in severe cases.
- Shoulder impingement: An irritation or inflammation of the rotator cuff tendons due to overuse or repetitive motion. Symptoms include pain and weakness when lifting or reaching overhead. Treatment includes rest, physical therapy, anti-inflammatory medication, and cortisone injections in severe cases.
- Dislocated shoulder: When the upper arm bone comes out of the shoulder socket due to direct impact or trauma. Symptoms include severe pain and inability to move the arm. Treatment includes sedation and relocation of the shoulder joint and immobilization with a sling for several weeks.
Treatment for Shoulder Injuries
Treatment for shoulder injuries depends on the severity of the injury and the underlying cause. Here are some of the common treatment options:
- Rest: Resting the shoulder and avoiding activities that exacerbate pain or inflammation is the first line of treatment for most shoulder injuries.
- Physical therapy: A physical therapist can design a customized exercise program to help strengthen and stretch the shoulder muscles, reduce pain, and improve range of motion.
- Anti-inflammatory medication: Non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or aspirin can help reduce pain and inflammation.
- Cortisone injections: In severe cases of inflammation or pain, a cortisone injection may be given directly into the shoulder joint to reduce inflammation and pain.
- Surgery: Surgery may be necessary in severe cases such as rotator cuff tears or dislocated shoulder joints.
Shoulder Rehabilitation Exercises
Rehabilitation exercises are an important part of the treatment plan for shoulder injuries. The following exercises can help improve strength, flexibility, and range of motion:
| Exercise | Description |
|---|---|
| External rotation | Lie on your unaffected side with the elbow of your affected arm bent at 90 degrees. Hold a light weight in your hand and slowly rotate your arm outward, keeping your elbow close to your body. Repeat for 10-15 repetitions. |
| Internal rotation | Stand with a resistance band attached to a stationary object and holding the other end of the band with your affected arm. Start with your hand by your stomach and slowly rotate your arm inward across your body. Repeat for 10-15 repetitions. |
| Scapular retraction | Stand with your arms at your sides and shoulder blades squeezed together. Hold for 5-10 seconds and repeat for 10-15 repetitions. |
It is important to seek medical attention if you experience persistent pain, weakness, or limited range of motion in your shoulder. Early diagnosis and treatment can help prevent further damage and improve recovery outcomes.
Importance of Stretching Before Shoulder Workouts
Stretching plays a crucial role in every workout routine, especially before a shoulder workout. It is an essential component of a warm-up routine as it helps to increase blood flow, loosen up muscles, and reduce the risk of injury.
It is crucial to have proper shoulder mobility to perform exercises that involve lifting arms out to the side such as lateral raises, upright rows, and lateral pull-downs. Lack of flexibility in the shoulders can lead to poor form, which can cause undue stress on the shoulders and result in painful injuries and impingement. Therefore, stretching the shoulder muscles before a workout can significantly enhance the quality of your shoulder exercises.
7 Shoulder Stretches to Incorporate in your Warm-up Routine
- Shoulder Rolls
- Arm Across Chest Stretch
- Overhead Triceps Stretch
- Doorway Stretch
- Chest and Shoulder Stretch
- Side Lying Rotation
- Thread the Needle Stretch
Performing these stretches for approximately 10-15 minutes before a workout can help to improve the flexibility of the shoulder muscles, increase the range of motion, and reduce the risk of injury.
Another essential factor to keep in mind when stretching before a shoulder workout is to make sure that you don’t overstretch. Overstretching may lead to tears and cause more harm than good. Hence, it is essential to stretch just enough to feel tension in the muscles and hold the stretch for approximately 20-30 seconds.
Shoulder Stretches for Shoulder Injury Recovery
If you have suffered a shoulder injury or experiencing shoulder pain, incorporating the following stretches in your routine can help in the recovery process.
- Pendulum Swing
- Shoulder Blade Squeezes
- Shoulder External Rotation Stretch
Performing these exercises can help improve shoulder mobility, reduce pain, and promote healing in the shoulder muscles.
Remember, stretching before a workout is as essential as the workout itself. Incorporate these stretches in your shoulder routine, and you’ll notice a significant improvement in your shoulder mobility and flexibility.
FAQs: What Muscle Lifts Arm Out to Side?
1. What is the muscle responsible for lifting the arm out to the side?
The muscle that lifts the arm out to the side is the deltoid muscle.
2. What other muscles are involved in lifting the arm out to the side?
The supraspinatus muscle, part of the rotator cuff, is also involved in lifting the arm out to the side.
3. How do I strengthen the muscles responsible for lifting the arm out to the side?
To strengthen the deltoid and supraspinatus muscles, you can do exercises such as lateral raises, overhead presses, and external rotations.
4. Can lifting weights incorrectly cause damage to the muscles that lift the arm out to the side?
Yes, lifting weights incorrectly or using too much weight can lead to strains or tears in the deltoid and rotator cuff muscles.
5. Are there any stretches that can help prevent injury to the muscles that lift the arm out to the side?
Stretching the chest and shoulders can help prevent injury to the muscles that lift the arm out to the side. The doorway stretch and the sleeper stretch are both effective stretches for this purpose.
6. What can I do if I experience pain when lifting my arm out to the side?
If you experience pain when lifting your arm out to the side, it is important to rest and avoid activities that aggravate the pain. You should also seek medical attention to determine the cause of the pain and receive appropriate treatment.
Closing Thoughts
Thanks for reading our article on what muscle lifts the arm out to the side! Strengthening and stretching exercises can help prevent injury and keep your muscles healthy. If you experience any pain or discomfort, be sure to take appropriate precautions and seek medical attention if needed. Visit us again soon for more health and fitness tips!