What Systematic recommends
Where to start
- Stand next to the wall or other rigid surface that will not give way with bare feet flat on the ground and choose a fixed visual point directly in front of you to focus on.
- Stand tall and bring your attention to the tripod points of contact through the foot, briefly lock the standing knee then unlock it into a soft, active position and reach to the wall with two fingertips using only very light contact.
- Keep your eyes focused straight ahead on your chosen visual point, lift the inside foot approximately 6–12 inches off the ground, breathe normally, begin with a 10-second hold, progress in 10-second increments and work toward a 30-second hold.
Condensed from the published Development Pathway (Single-Leg Balance: Two Finger Wall-Assist Tripod Stand). This is a starting point, not a training program or medical advice.
Balance is a constant blending job
Your balance draws on three streams of information: vision, the vestibular system of the inner ear, and somatosensory information from the body itself. Postural control comes from how the nervous system combines those streams and reweights them from moment to moment.
Vision is one major source. When it is removed, as when you close your eyes, the nervous system has to place more weight on the senses that remain and reorganize how it controls posture.
What changes with age
Research on aging, reviewed by Henry and colleagues in 2019, describes several changes. Position sense from the legs becomes less sensitive and less well integrated. People rely more on vision. And reweighting between the senses becomes slower or less flexible.
Muscle activity changes as well. Opposing muscles around a joint tend to contract at the same time more often (antagonist coactivation), and the ankle and hip strategies people use to stay upright shift.
What this means for an eyes-closed balance test
With the eyes closed, balance depends more on the remaining senses and on postural strategy, which are the parts of the system these age-related changes touch. Taking vision away exposes how well they hold up.
A balance result reflects that whole system. The Systematic test is not a check of foot-to-brain wiring or of the receptors in the sole of the foot alone, and it does not diagnose a problem in any one sensory pathway.
The evidence
Each cited source is labeled according to how it supports the particular claim on this page. Direct test evidence, underlying-capacity findings and population reference values are distinguished from Systematic-defined protocols and standards. Historical development notes are retained internally rather than presented as public evidence. A study of an underlying capacity is never presented as validation of the Systematic test itself.
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Underlying-capacity evidence
Peterka (2002). Sensorimotor Integration in Human Postural Control. Journal of Neurophysiology.
What it found. Postural control comes from combining and reweighting visual, vestibular and somatosensory information; removing vision shifts weight onto the senses that remain.
What it does not show. It does not show that balance rests on a single sensory receptor, and it did not test the Systematic balance test.
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Underlying-capacity evidence
Henry et al. (2019). Age-related changes in leg proprioception: implications for postural control. Journal of Neurophysiology.
What it found. With age: less sensitive leg position sense, more reliance on vision, slower or less flexible reweighting, more antagonist coactivation, and changed postural strategies.
What it does not show. It does not show which change explains a given person's balance, and it did not test the Systematic balance test.
The Systematic Healthspan Assessment is a physical baseline. It is not a diagnosis, and it does not estimate a biological age, a disease risk or a lifespan.