Mobility: Understanding Passive, Active, and Controlled Articular Rotation

What are the 3 levels of mobility?

Mobility, distinct from mere flexibility, encompasses the active control, strength, and neurological command over a joint's full range of motion. Understanding these three progressive levels—Passive Range of Motion, Active Range of Motion, and Controlled Articular Rotation—is crucial for optimizing movement health, performance, and injury prevention.

Understanding Mobility: More Than Just Flexibility

Before delving into the levels, it's vital to clarify what mobility truly is. Flexibility refers to the passive lengthening of soft tissues (muscles, tendons, ligaments) around a joint, allowing for a certain range of motion, often achieved with external assistance. Mobility, on the other hand, is the active ability to move a joint through its full range of motion with control, strength, and neurological input. It's about owning that range, not just possessing it.

Mobility is a critical component of:

• Joint Health: Ensuring synovial fluid distribution and cartilage nourishment.
• Injury Prevention: Preparing joints and surrounding tissues for varied stresses.
• Performance Enhancement: Allowing for optimal movement patterns in sport and daily life.
• Pain Reduction: Addressing restrictions that can contribute to compensatory movements and discomfort.

The Three Levels of Mobility

The concept of "levels" helps us understand the progression from simply possessing range to actively controlling and strengthening it.

Level 1: Passive Range of Motion (PROM)

Definition: Passive Range of Motion refers to the maximum extent a joint can be moved by an external force (e.g., a therapist, gravity, a strap, or your other hand) without the active muscular contraction of the person whose joint is being moved.

What it indicates:

• Tissue Extensibility: The length and elasticity of muscles, tendons, ligaments, and fascia surrounding the joint.
• Joint Capsule Integrity: The health and pliability of the fibrous capsule enclosing the joint.
• Absence of Bony Blocks: Structural limitations that might prevent further movement.

Importance: PROM is the potential range available to a joint. If you don't have adequate PROM, you physically cannot achieve that position, regardless of your strength. It's the foundation upon which active control is built. Exercises like static stretching, PNF stretching (when assisted), and manual therapy often aim to improve PROM.

Level 2: Active Range of Motion (AROM)

Definition: Active Range of Motion is the extent to which a joint can be moved by the active contraction of the muscles that cross that joint, without any external assistance.

What it indicates:

• Muscular Strength: The ability of the muscles to generate force to move the limb through the range.
• Neuromuscular Control: The brain's ability to coordinate muscle activation and inhibition effectively.
• Motor Control: The learned ability to execute smooth, controlled movements.

Importance: AROM is the usable range of motion. It tells us how much of your passive range you can actually control yourself. Ideally, your AROM should be close to your PROM. A significant discrepancy (e.g., you can passively lift your leg much higher than you can actively lift it) indicates a lack of strength or control in those end ranges, which is a common area for injury. Dynamic stretches and bodyweight movements often target AROM.

Level 3: Controlled Articular Rotation (CARs) / End-Range Control

Definition: This advanced level involves actively and slowly rotating a joint through its entire available active range of motion, with a conscious effort to expand and control the outer limits of that range. It emphasizes generating tension and strength at the end ranges of motion. This concept is popularized by systems like Functional Range Conditioning (FRC).

What it indicates:

• Neurological Drive & Irradiation: The ability to create tension throughout the body to stabilize and isolate the moving joint, enhancing neural input to the joint.
• End-Range Strength & Control: The capacity to generate force and maintain stability at the extreme limits of the joint's active movement.
• Proprioception & Kinesthetic Awareness: A heightened sense of the joint's position and movement in space.
• Articular Health: The deliberate and controlled movement helps distribute synovial fluid, nourish cartilage, and maintain joint capsule health.

Importance: CARs and end-range control are about owning your mobility. They bridge the gap between simply having range and being strong and resilient within that range. By regularly moving joints through their full, controlled active range, you communicate to your nervous system that these ranges are safe and usable, thereby expanding and solidifying your functional mobility and reducing the risk of injury from sudden, uncontrolled movements.

Why Differentiate These Levels?

Understanding these three levels allows for a more targeted and effective approach to mobility training:

• If PROM is limited, the focus should be on tissue extensibility through stretching, foam rolling, or manual therapy.
• If AROM is significantly less than PROM, the focus should be on strengthening the muscles responsible for moving the joint through its active range, particularly in the weaker end ranges.
• If AROM is good but control is lacking, especially at end-ranges, the focus should be on exercises like CARs to build neurological control, end-range strength, and joint resilience.

Practical Application: Integrating Mobility Training

A comprehensive mobility program should ideally address all three levels:

1. Initial Assessment: Identify areas of restricted PROM and discrepancies between PROM and AROM.
2. Targeted PROM Improvement: Use static stretches, PNF, or soft tissue work to increase tissue extensibility where needed.
3. AROM Development: Incorporate dynamic movements, bodyweight exercises, and movements that take joints through their full active range.
4. End-Range Control and Strength: Regularly practice CARs for all major joints, focusing on slow, deliberate, and maximal effort contractions at the end ranges. Isometric holds at end range are also highly effective.
5. Integration into Movement: Apply improved mobility to functional movements, compound lifts, and sport-specific activities.

Conclusion: A Holistic Approach to Movement Health

Mobility is not a static state but an ongoing practice of maintaining and expanding your body's potential for movement. By understanding and training the three levels of mobility—Passive Range of Motion, Active Range of Motion, and Controlled Articular Rotation—you move beyond simple flexibility to cultivate robust, resilient, and highly functional joints. This holistic approach empowers you to move with greater freedom, control, and confidence, significantly enhancing your overall physical health and athletic performance.