Planks: Why Your Arms Hurt More Than Your Core and How to Fix It

Why do planks hurt my arms more than my core?

Planks frequently cause more discomfort in the arms than the core primarily due to improper form, insufficient upper body stability, and a lack of conscious core engagement, leading to excessive reliance on the shoulders, triceps, and wrists to maintain the position rather than the intended abdominal and spinal musculature.

Understanding the Plank: More Than Just a Core Exercise

The plank is renowned as a foundational isometric exercise for core stability. However, its execution demands integrated strength and stability from various muscle groups beyond just the rectus abdominis and obliques. A true plank is a full-body engagement, requiring synergistic activation of the core, glutes, quads, and particularly the muscles of the shoulder girdle and arms to create a rigid, straight line from head to heels. When the core fails to engage optimally, the body compensates by shifting the load to more easily fatigued support structures, often the arms and shoulders.

Common Biomechanical Reasons for Arm Discomfort

Several biomechanical factors and common errors can shift the primary load from your core to your upper extremities during a plank.

• Incorrect Form & Alignment:
  • Shoulder Positioning: Often, individuals allow their shoulders to elevate towards their ears or their shoulder blades to "wing" or collapse. This puts undue stress on the trapezius and levator scapulae muscles, which are not designed for sustained isometric support in this manner. Instead, the shoulders should be depressed and retracted, creating a stable platform.
  • Elbow Placement: If your elbows are positioned too far forward or too far back relative to your shoulders, it alters the leverage, forcing your triceps and deltoids to work harder to maintain the static hold. Elbows should be directly beneath the shoulders.
  • Hand/Forearm Pressure: Excessive pressure through the hands or elbows (depending on the plank variation) can indicate a compensatory strategy. If you're gripping the floor tightly or digging your elbows in, you're likely over-relying on these points of contact because your core isn't providing sufficient stability.
• Lack of Core Engagement:
  • Pelvic Tilt: A common error is allowing the hips to sag (anterior pelvic tilt) or pike too high (posterior pelvic tilt). Both positions disengage the deep core muscles (transversus abdominis, multifidus) and shift the load. Sagging hips place stress on the lower back, while piking hips reduces the challenge to the core, allowing the arms to take over.
  • Spinal Alignment: The goal is a neutral spine. If your back is excessively arched or rounded, the core's ability to act as a brace is compromised, leading to the arms bearing more of the body's weight.
• Upper Body Weakness Relative to Core Strength:
  • Scapular Stability: The muscles surrounding the shoulder blades (serratus anterior, rhomboids, lower trapezius) are crucial for stabilizing the shoulder joint. If these muscles are weak or not properly activated, the shoulders will struggle to maintain their position, leading to rapid fatigue and discomfort in the arms and upper back.
  • Triceps and Deltoid Fatigue: While these muscles are involved in supporting the body, they are not the primary movers for a plank. If your core isn't effectively bracing, your triceps (which extend the elbow) and deltoids (which stabilize the shoulder) will bear an disproportionate amount of the load, leading to burning sensations and fatigue.
• Over-reliance on Passive Structures: When muscles fatigue or fail to engage, the body often resorts to hanging on ligaments and joint capsules, particularly in the shoulders and elbows. This can cause discomfort, strain, and even contribute to joint issues over time.

The Anatomy Behind the Discomfort

Understanding the specific anatomical structures involved clarifies why discomfort manifests in the arms.

• Shoulder Girdle: This complex of bones (scapula, clavicle, humerus) and muscles (rotator cuff, deltoids, trapezius, serratus anterior) is crucial for supporting the upper body's weight. When form is compromised, muscles like the anterior deltoids and triceps work overtime to prevent shoulder collapse, leading to fatigue. The trapezius and levator scapulae can become strained if the shoulders are shrugged.
• Elbow Joint: The triceps brachii muscle, which extends the elbow, is constantly engaged during a forearm plank. If the core isn't stabilizing the trunk, the triceps will bear excessive load, leading to a burning sensation.
• Wrist Joint: In a high plank, the wrists bear significant weight. Poor alignment (wrists not directly under shoulders), lack of wrist mobility, or weak forearm muscles can lead to strain and pain in the wrist extensors and flexors.

How to Re-Engage Your Core and Reduce Arm Strain

To shift the load back to your core and alleviate arm discomfort, focus on these corrective strategies:

• Mastering Proper Form:
  • Elbows Under Shoulders: Ensure your elbows are directly beneath your shoulders for forearm planks, or wrists under shoulders for high planks.
  • Neutral Spine: Imagine a straight line from your head to your heels. Avoid arching or rounding your back. Engage your glutes by squeezing them gently to prevent hip sagging.
  • Engage Your Core: Think about drawing your navel towards your spine (without holding your breath) and bracing as if preparing for a punch to the stomach. This activates the transversus abdominis.
  • "Pull" the Floor: For forearm planks, imagine pulling your elbows towards your toes and your toes towards your elbows without actually moving. This isometric action can help activate the lats and serratus anterior, creating more upper body stability.
  • Depress Shoulders: Actively push the floor away (for high plank) or press your forearms into the ground (for forearm plank) to prevent your shoulders from shrugging up towards your ears. This engages the serratus anterior and helps stabilize the scapula.
• Mind-Muscle Connection: Consciously focus on feeling your core muscles work. If you feel it more in your arms, adjust your form until you feel the burn in your abdominals.
• Progressive Overload & Variations:
  • Start on Knees: If maintaining proper form on your toes is too challenging, begin with a plank from your knees to build core strength and learn the proper body alignment.
  • Shorter Durations: Focus on holding perfect form for shorter periods (e.g., 15-30 seconds) rather than struggling through longer, poorly executed planks.
  • Plank Variations: Incorporate dynamic planks (e.g., plank with hip dips, plank shoulder taps) or stability ball planks to challenge your core in different ways and improve proprioception.
• Strengthen Supporting Muscles: Incorporate exercises that strengthen the muscles responsible for shoulder and scapular stability, such as:
  • Push-ups (focus on full range of motion and scapular protraction)
  • Rows (e.g., bent-over rows, cable rows)
  • Overhead presses (light weight, focus on shoulder stability)
  • Face pulls

When to Seek Professional Guidance

If you consistently experience significant pain (not just muscle fatigue) in your arms, shoulders, or wrists during planks, or if you're unable to achieve proper core engagement despite trying corrective measures, consider consulting a qualified fitness professional, physical therapist, or kinesiologist. They can assess your form, identify underlying muscle imbalances or weaknesses, and provide personalized guidance to help you perform planks safely and effectively.

Conclusion

The plank is a powerful core exercise, but its effectiveness hinges on proper execution and integrated body awareness. Arm discomfort during planks is a common indicator that your core isn't bearing its intended load, often due to subtle form errors or relative weaknesses in supporting muscles. By meticulously focusing on alignment, consciously engaging your core, and strengthening your shoulder girdle, you can transform your plank from an arm-straining ordeal into a truly effective core-strengthening movement.