The single-leg stance (OLS) test measures how long a person can stand unassisted on one foot. It is a simple, non-invasive assessment of postural stability that reflects the complex integration of multiple body systems. Scientific studies have linked the inability to maintain a single-leg stance for 20 seconds or more to underlying health issues. Failing this test may signal a need for closer medical evaluation, suggesting a subtle decline in neurological or vascular health that might otherwise go unnoticed.
The Medical Significance of Single-Leg Stance Time
The inability to hold a one-legged stance for 20 seconds is associated with vascular and cognitive health issues. A study published in the journal Stroke, involving nearly 1,400 adults in Japan, established a correlation between poor balance time and brain abnormalities. Researchers found that individuals who struggled to stand on one leg for 20 seconds were significantly more likely to have cerebral small vessel disease.
This small vessel disease includes conditions like lacunar infarctions and microbleeds, often called “silent strokes” because they typically do not produce noticeable symptoms. Approximately 34.5% of subjects with more than two lacunar infarctions, small areas of dead tissue caused by a blocked artery, had difficulty maintaining the stance. Thirty percent of those with multiple microbleeds, tiny hemorrhages in the brain, also failed the test.
The presence of these silent strokes indicates damage to the brain’s blood supply and is linked to an increased risk of future major strokes and cognitive decline. Beyond neurological health, a separate 12-year international study focused on the 10-second threshold and found a link to broader longevity. Middle-aged and older adults unable to hold the one-legged stance for 10 seconds were nearly twice as likely to die from any cause within the following decade compared to those who passed the test.
The Body Systems That Control Balance
Maintaining a stable single-leg stance requires the precise cooperation of three distinct sensory systems that feed information to the brain.
Proprioception functions as the body’s internal positioning sense. Specialized receptors in muscles, joints, and skin provide the brain with continuous feedback about the body’s position in space, even without looking.
The visual system provides external reference points for spatial orientation. The eyes offer information about the environment, the horizon, and the body’s movement relative to fixed objects. This visual input helps the brain anticipate and correct for shifts in balance.
The vestibular system, located within the inner ear, acts as an internal gyroscope. It detects head movements and changes in gravitational pull, sending signals about spatial orientation and acceleration to the brain. When all three systems are functioning optimally, the brain seamlessly integrates their signals to make the continuous adjustments necessary to remain upright on one foot.
Underlying Health Conditions Indicated by Poor Balance
A decline in single-leg stance time can point to an impairment in one or more of the three balance systems. Conditions affecting the peripheral nerves, such as peripheral neuropathy, directly compromise proprioception. Nerve damage, often caused by diabetes, results in diminished sensation in the feet and legs, preventing the brain from receiving accurate information about the body’s contact with the ground.
Issues within the inner ear can disrupt the vestibular system, leading to balance problems. Common inner ear disorders include Benign Paroxysmal Positional Vertigo (BPPV), which involves displaced crystals, and Meniere’s disease, which affects fluid balance. These conditions can cause sudden, intense vertigo or chronic unsteadiness that makes single-leg balancing impossible.
Neurological conditions that affect the central processing centers in the brain also contribute to poor balance. Parkinson’s disease, for example, impairs the brain’s motor control regions, leading to postural instability and delayed reflexes. The silent strokes associated with a poor 20-second stance time also belong to this category, as they affect the brain’s capacity to coordinate the sensory inputs needed for stable posture.
Actionable Steps to Improve Balance
Improving balance involves exercises that challenge the three sensory systems and strengthen the supporting muscles. Single-leg stance practice is a direct and effective method for improvement, ideally performed near a wall or sturdy surface for safety. Begin by holding the stance for short durations and gradually increasing the time, aiming to reach 30 seconds or more on each leg.
Incorporating dynamic movements, such as heel-to-toe walking, enhances coordination and stability by forcing the body to manage a narrow base of support. Movement practices like Tai Chi are beneficial because their slow, deliberate motions simultaneously engage the core muscles and improve proprioceptive awareness. These exercises retrain the brain to process balance signals more efficiently.
It is important to review medications with a healthcare provider, as many common drugs can cause dizziness or drowsiness that interferes with balance. If balance issues appear suddenly, cause frequent falls, or are accompanied by symptoms like persistent dizziness, vertigo, or blurred vision, a physician should be consulted immediately. These symptoms may signal an underlying medical condition requiring professional diagnosis and treatment.