A hand squeeze and five chair stands predicted nine long-term conditions

The two cheapest tests in sports medicine are a handheld dynamometer and a chair. A systematic review published in the British Journal of Sports Medicine asked what those two tests actually predict about the decades that follow, and pooled 94 cohort studies to answer it [s1].

The framing matters. This is not a study about training. Nobody in these cohorts was randomised to lift anything. It is a study about measurement — whether a number you can collect in a clinic in under a minute carries prognostic information about conditions that arrive decades later.

What was pooled

The authors searched seven databases for cohort studies testing the predictive value of validated field-based muscular strength tests against incident long-term health conditions in adults aged 18 and over [s1]. A total of 155 studies met the inclusion criteria, of which 94 contributed to the meta-analysis [s1].

Two tests dominate the literature: handgrip strength, and the five-repetition chair-stand test, in which a person rises from a seated position five times as quickly as they can.

The grip strength results

Comparing adults in the highest handgrip category with those in the lowest, every association ran in the same direction, and all were statistically significant [s1]:

• cardiovascular disease, odds ratio 0.73 (95% CI 0.67 to 0.80)
• type 2 diabetes, OR 0.79 (0.68 to 0.91)
• musculoskeletal impairment, OR 0.65 (0.56 to 0.76)
• disability, OR 0.57 (0.47 to 0.70)
• anxiety, OR 0.79 (0.63 to 0.99)
• depression, OR 0.70 (0.63 to 0.78)
• cognitive decline, OR 0.57 (0.44 to 0.75)
• dementia, OR 0.62 (0.53 to 0.73)
• Parkinson's disease, OR 0.53 (0.31 to 0.91)

A 5 kg increase in handgrip strength was associated with lower risk of developing most of these conditions [s1].

The chair-stand test predicted a narrower set: type 2 diabetes (OR 0.80; 0.72 to 0.88), musculoskeletal impairment (OR 0.52; 0.37 to 0.74), disability (OR 0.58; 0.41 to 0.82), depression (OR 0.63; 0.42 to 0.95) and dementia (OR 0.68; 0.54 to 0.85) [s1]. Every one-second reduction in the time taken was associated with 0.94 lower odds of musculoskeletal impairment [s1].

The part that gets left out

The authors graded the overall quality of the evidence as ranging from very low to moderate, which they translate as limited to moderate confidence in the results [s1]. That grade is not a footnote. It is the difference between a screening test and an interesting correlation.

A pooled odds ratio also cannot distinguish a risk factor from an early symptom. If declining grip is a downstream sign of a process already underway — a possibility this design cannot exclude — it would produce exactly the associations reported here, with Parkinson's disease and dementia among the strongest [s1]. Nothing in the analysis separates the two readings.

The anxiety result illustrates the fragility. Its confidence interval runs from 0.63 to 0.99 [s1] — it clears significance, but only just, and the upper bound is close enough to 1.00 that a single additional cohort could move it.

What it is useful for

The authors' own conclusion is about clinical utility rather than causation: simple field-based strength tests appear clinically useful for adults across different age groups and demographic profiles [s1]. That is a claim about triage. A clinician who measures grip strength learns something about which patients warrant closer attention, without learning anything about what to do next.

The distinction gets lost quickly in translation. A finding that low grip strength predicts dementia becomes, within one retelling, advice to train grip strength to prevent dementia. This review supports the first sentence and says nothing about the second.

What to watch

The chair-stand test is the more interesting of the two, because it is free, needs no equipment, and captures lower-body power, balance and coordination together. It also has thinner evidence here — fewer conditions reached significance, and the pooled estimates rest on fewer studies than grip strength.

Whether either test earns a place in routine adult care depends on evidence this review could not supply: whether measuring them changes what clinicians do, and whether that change improves anything. Prognostic value and clinical value are separate questions, and only the first has been answered.

This article is informational and is not medical advice.