# Why Both One-Leg Stand Times May Matter

> In 3,278 independent older adults in Japan, a shorter time on the weaker side was associated with later loss of independence or death, even when the better side reached 30 seconds.

_Source: JAMDA population cohort study, verified against PubMed, Crossref and OpenAlex · 2026-09-26 · 7 min read · Verified against primary sources_

Canonical: https://iyu.app/e/bilateral-one-leg-stand-prognosis-older-adults

## The 60-second version

The shorter of two one-leg stand times was associated with severe loss of independence or death over follow-up in independently living older Japanese adults.

**Key points**

- The cohort included 3,278 adults aged 65 or older and recorded 452 composite events over a median 7.22 years.
- Compared with at least 30 seconds, adjusted hazard ratios were 2.17 below 10 seconds and 1.54 from 10 to 20 seconds.
- The shorter side remained informative even when the better side reached at least 30 seconds.
- The observational design, composite endpoint and two-community sample prevent causal or universal conclusions.

**Verdict.** Measuring both sides may improve low-cost risk assessment, but the result belongs inside a broader clinical evaluation and does not predict an individual's fate.

## Full explainer

Among 3,278 independent Japanese adults aged 65 or older, the **shorter result from bilateral one-leg standing tests** was associated with later severe loss of independence or death. The signal remained even when the better-performing leg reached 30 seconds.

> **⚑ Caveat:** This was an observational cohort. A short standing time is a risk marker, not proof of causation, a diagnosis, or evidence that improving the test will prevent disability or death.


### Design — A bilateral test followed over seven years

- **Population:** 3,278 independently living adults aged 65 or older in two Japanese municipalities.
- **Exposure:** The secondary one-leg stand time: the shorter result from the two sides.
- **Follow-up:** Median 7.22 years after testing between 2008 and 2010.
- **Outcome:** Death or severe loss of independence requiring complete help with basic daily activities.

- **3,278** — participants
- **452** — composite events
- **13.7%** — reached the endpoint
- **7.22 y** — median follow-up


### Results — Risk rose below twenty seconds

- **Under 10 seconds:** Adjusted hazard ratio 2.17; 95% CI 1.67 to 2.84, compared with at least 30 seconds.
- **10 to 20 seconds:** Adjusted hazard ratio 1.54; 95% CI 1.13 to 2.10.
- **20 to 30 seconds:** Adjusted hazard ratio 0.88; 95% CI 0.56 to 1.37, with no clear increase.
- **Better side at least 30 seconds:** The shorter side still carried an association in the restricted analysis.

Hazard ratios compare event rates over time after adjustment; they are not probabilities. The reference was a shorter-side time of at least 30 seconds. Confidence intervals show that the 20-to-30-second estimate remained compatible with both lower and higher risk.


### Meaning — A screening signal, not a single-number verdict

- **1. Confounding:** balance can reflect neurological, musculoskeletal, visual, medication and general-health factors.
- **2. Composite outcome:** severe dependency and death are distinct events and should not be collapsed into a mortality claim.
- **3. Generalizability:** the cohort began with independent older adults in two Japanese communities.
- **4. Safety:** people at fall risk should not attempt unsupervised threshold testing.

> Testing only the better leg may discard useful information, but testing both legs does not turn balance into destiny.


### Practice — Use both sides within a broader assessment

Bilateral testing could complement gait speed, strength, fall history, cognition, vision, medication review and daily function. A short result should lead to clinical context and safer evaluation, not self-diagnosis.

The authors declared no conflicts of interest. Intervention studies are still needed to learn whether acting on the weaker-side result changes severe dependency or survival.


## Primary sources

- [Telegram post 1509](https://t.me/CNSmydream/1509)
- [JAMDA paper](https://doi.org/10.1016/j.jamda.2025.105688)
- [PubMed record](https://pubmed.ncbi.nlm.nih.gov/40409342/)
- [Crossref record](https://api.crossref.org/works/10.1016/j.jamda.2025.105688)
- [OpenAlex record](https://openalex.org/W4410718152)

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