Pushups and the AC Joint: Understanding Risks, Proper Form, and Injury Prevention

Are pushups bad for AC joint?

Pushups are not inherently bad for the AC joint, but improper form, pre-existing conditions, excessive volume, or a lack of shoulder stability can certainly exacerbate or lead to AC joint discomfort or injury.

Understanding the AC Joint

The acromioclavicular (AC) joint is a crucial articulation in the shoulder complex, connecting the acromion (part of the shoulder blade, or scapula) to the clavicle (collarbone). Unlike the highly mobile glenohumeral (shoulder) joint, the AC joint is a relatively small, gliding joint primarily responsible for transmitting forces from the upper extremity to the axial skeleton and allowing subtle movements of the scapula relative to the clavicle.

Key functions of the AC joint include:

• Stabilizing the shoulder girdle: It helps maintain the proper positioning of the scapula and clavicle.
• Facilitating scapular motion: It allows the scapula to rotate, elevate, depress, protract, and retract, which are essential for full range of motion in the arm, especially overhead movements.

Common AC joint issues often involve:

• Sprains or separations: Resulting from direct trauma, such as a fall onto the shoulder.
• Osteoarthritis: Degenerative changes due to wear and tear over time.
• Inflammation (AC joint synovitis): Often caused by overuse or repetitive stress.

The Biomechanics of a Pushup

The pushup is a fundamental compound exercise that primarily targets the chest (pectoralis major), shoulders (anterior deltoid), and triceps. It also heavily engages the core and numerous stabilizing muscles, including those around the scapula (serratus anterior, rhomboids, trapezius).

During a pushup, the AC joint experiences forces related to:

• Scapular movement: As you lower and press up, your scapulae should protract (move away from the spine) and retract (move towards the spine) smoothly, controlled by the serratus anterior and rhomboids.
• Shoulder flexion and horizontal adduction: The arms move in front of the body, which involves the AC joint contributing to the overall stability and movement of the shoulder girdle.
• Weight bearing: The AC joint, along with the entire shoulder complex, bears a significant portion of your body weight.

A well-executed pushup promotes robust shoulder stability and strength. However, when biomechanics are compromised, the AC joint can become vulnerable.

Pushups and AC Joint Stress: When Do Problems Arise?

While pushups are generally safe and effective, certain factors can place undue stress on the AC joint, potentially leading to pain or injury.

• Poor Form and Scapular Dysfunction: This is arguably the most common culprit.
  • Lack of Scapular Protraction: If the shoulder blades "wing" or collapse inwards (excessive retraction) at the bottom of the pushup, it can pinch the AC joint or strain its ligaments. The serratus anterior is crucial for protracting and upwardly rotating the scapula, preventing this.
  • Shoulder Shrugging: Elevating the shoulders towards the ears (upper trapezius dominance) can compress the AC joint.
  • Elbows Flared Out: This puts the shoulder joint in a vulnerable position, increasing internal rotation and potentially stressing the AC joint and rotator cuff.
• Pre-existing AC Joint Issues: Individuals with a history of AC joint separation, osteoarthritis, or chronic inflammation may find pushups aggravating, especially without modification.
• Excessive Volume or Intensity: Doing too many pushups, too frequently, or progressing too quickly can overload the joint and surrounding tissues, leading to inflammation or tendinopathy.
• Lack of Overall Shoulder Stability: Weakness in the rotator cuff muscles or poor control of the scapula can lead to compensatory movements that stress the AC joint.
• Improper Hand Placement:
  • Hands too wide: Increases horizontal abduction, placing more stress on the AC joint and anterior capsule.
  • Hands too high (above shoulder level): Forces the shoulder into an awkward, internally rotated position at the bottom, potentially irritating the AC joint.

Safe Pushup Execution: Protecting Your AC Joint

To perform pushups safely and effectively, minimizing risk to the AC joint, focus on these key principles:

• Master Proper Form:
  • Neutral Spine: Maintain a straight line from head to heels, engaging your core. Avoid sagging hips or arching your lower back.
  • Scapular Control: As you lower, allow your shoulder blades to retract slightly, but crucially, protract (push away from the spine) forcefully at the top. Think about "pushing the floor away" and rounding your upper back slightly as you extend your arms. This engages the serratus anterior, which is vital for AC joint health.
  • Elbow Angle: Keep your elbows tucked in at approximately a 45-degree angle to your torso, not flared straight out to the sides. This optimizes shoulder mechanics.
  • Controlled Descent and Ascent: Avoid dropping down quickly. Control the movement throughout the full range.
• Optimal Hand Placement:
  • Place hands slightly wider than shoulder-width apart, with your middle finger pointing forward.
  • Ensure your wrists are directly under your shoulders at the top of the movement.
• Listen to Your Body: If you feel any sharp pain in your AC joint or shoulder, stop immediately. Persistent discomfort is a sign to modify the exercise or seek professional advice.
• Progress Gradually: Don't attempt advanced variations or high volumes before mastering the basic pushup. Start on an incline (hands on a bench or wall) to reduce load, then progress to the floor, and eventually to more challenging variations.
• Incorporate Scapular Stability Exercises: Exercises like face pulls, band pull-aparts, Y-T-W-L raises, and serratus anterior punches can strengthen the muscles that stabilize the scapula and support the AC joint.
• Vary Your Pushup Stance: Experiment with different hand positions (e.g., slightly narrower, diamond pushups) and ensure they don't exacerbate any discomfort. Some individuals find neutral grip pushup handles more comfortable.

When to Consult a Professional

If you experience persistent pain in your AC joint during or after pushups, or if you have a known AC joint injury, it is highly recommended to consult a qualified healthcare professional, such as a physical therapist, sports medicine physician, or orthopedic specialist. They can accurately diagnose the issue, provide personalized guidance on exercise modifications, and recommend appropriate rehabilitation strategies to ensure your long-term shoulder health.