This article originally appeared in Psychology Today.

When each of us sits down, we navigate our feet to a position that feels comfortable, even if the seat we are in is uncomfortable. What we may not realize is that how we position our feet may affect our ability to think and concentrate.

Over 40 years of clinical practice, I have learned that a seated person’s foot position can reflect postural problems that affect cognitive performance. When I am working with a patient, my peripheral eyesight is automatically aware of the patient’s foot position because both posture and foot position influence my ability to maximize a patient’s thinking ability. When both feet are flat on the ground (heel and toe), all energy can be used to focus and problem solve.

Observations of foot position can roughly clue a visual skill of spatial orientation. Each person uses visual inputs to provide accurate information on what is “straight ahead.” Often, if visual perception of the midline is off to one side, both feet might remain parallel to each other and point to that same side.

If there is an imbalance in eye teaming, one foot might be positioned outward or inward while the other foot points straight ahead. These small visual problems can cause an individual to lose their place when reading, avoid participating in ball sports, and challenge driving ability in traffic. An astute observer can catch these subtleties.