Pronation: Examples in the Foot, Forearm, and Shoulder, and When it Becomes a Concern

What is an example of pronation?

Pronation is a multi-planar biomechanical movement involving the rotation of a body segment. The most common and widely recognized example is foot pronation during walking or running, where the arch flattens to absorb impact and adapt to the ground.

Understanding Pronation: A Fundamental Biomechanical Movement

In the realm of human movement, pronation refers to a complex, multi-planar motion that combines specific rotations and translations of a body segment. It is a fundamental and entirely normal movement, essential for shock absorption, adapting to uneven surfaces, and efficient force transmission throughout the kinetic chain. While the specific components vary slightly depending on the joint, the general principle involves a combination of eversion, abduction, and dorsiflexion (or internal rotation).

The Primary Example: Foot Pronation During Gait

The most frequently discussed and critical example of pronation occurs in the foot during the gait cycle (walking or running). As the foot makes contact with the ground, it undergoes pronation to act as a mobile adaptor and shock absorber.

This complex movement at the foot and ankle involves a coordinated action primarily at the subtalar joint (between the talus and calcaneus) and the midfoot joints. The components of foot pronation are:

• Eversion: The sole of the foot turns outward.
• Abduction: The foot moves away from the midline of the body (outward rotation).
• Dorsiflexion: The foot flexes upward towards the shin.

How it works during gait: Upon initial contact with the ground (heel strike), the foot begins to pronate. This allows the arch of the foot to flatten, distributing the ground reaction forces over a larger area and absorbing impact. This "unlocking" of the midfoot joints makes the foot more flexible, enabling it to conform to the terrain. As the body moves over the foot into the propulsive phase, the foot then supinates (the opposite movement) to become a rigid lever for pushing off the ground.

Other Examples of Pronation in the Human Body

While foot pronation is the most prominent example, the term "pronation" also applies to other joints, describing similar multi-planar movements.

• Forearm Pronation:

  • This movement occurs at the radioulnar joints (proximal and distal).
  • It involves the rotation of the radius bone over the ulna, causing the palm of the hand to face downwards or backwards (if the arm is extended forward).
  • Common activities: Turning a doorknob clockwise with the right hand, using a screwdriver, typing on a keyboard, dribbling a basketball.

• Shoulder "Pronation" (Internal Rotation):

  • While technically referred to as internal rotation at the glenohumeral joint, this movement shares kinematic similarities to pronation in other joints.
  • It involves the inward rotation of the humerus (upper arm bone) within the shoulder socket.
  • Common activities: Throwing a ball (during the follow-through), pressing movements (like a bench press), reaching behind your back.

When Pronation Becomes a Concern: Overpronation

It is crucial to understand that pronation is a natural and necessary movement. Problems typically arise not from pronation itself, but from excessive or prolonged pronation, often referred to as overpronation.

In the context of the foot, overpronation means the arch collapses too much or stays pronated for too long during the gait cycle. This can lead to:

• Loss of efficient shock absorption: The foot remains too flexible.
• Altered biomechanics up the kinetic chain: Can affect the knees, hips, and lower back due to rotational forces.
• Increased risk of injuries: Such as plantar fasciitis, shin splints, patellofemoral pain syndrome, and Achilles tendinopathy.

The Importance of Balanced Pronation

As an essential component of human movement, balanced pronation allows our bodies to adapt, absorb forces, and move efficiently. Understanding these biomechanical principles is key for fitness enthusiasts, athletes, and healthcare professionals alike, enabling them to optimize movement patterns, prevent injuries, and enhance performance. Maintaining appropriate muscle strength, flexibility, and proper movement mechanics is vital to ensure that pronation serves its intended beneficial purpose without leading to adverse effects.