Why Does an Orthopaedic Surgeon Ask Which Hand You Write With?

Asking which hand you write with is not just a formality. The dominant hand often performs more tasks that require precision, while the other hand may stabilise objects, carry loads or perform different movements. Knowing this helps interpret strength, range of motion and function — but it does not mean that the dominant side must always perform better.

The dominant hand is not automatically the “stronger hand”

In healthy groups, the dominant upper limb is stronger on average, but the difference depends on the movement tested, the joint, work demands, sport and individual habits. A meta-analysis of 87 studies found an average strength advantage of about 11.6% for the dominant upper limb, while differences across particular movements and regions ranged from about 2% to nearly 20%. This means that the familiar “10% rule” can be a useful group-level approximation, but it is not a fixed standard for every person or every test.

Another study of 229 adults found that 32.3% recorded their greatest grip strength in the non-dominant hand. The sample was relatively small and 96.1% of participants were right-handed, so the result should not be applied rigidly to every patient. It does, however, show why a single measurement from one hand should not be interpreted according to a simple rule.

What does this change during an examination?

• Strength: a difference between sides may be normal, but it can also reflect pain, tendon injury, a nerve problem, a previous injury or reduced use of one hand.
• Precision and speed: writing, fastening buttons or using a tool depends on more than maximum grip strength.
• Range of motion: a small asymmetry may have existed before the current problem, especially with repetitive work or sport.
• Functional importance: the same loss of function may have very different consequences for someone who writes, plays an instrument, works with tools or performs tasks with both hands.

Why are both sides examined?

The other hand is a useful reference point, but it is not a perfect copy of what the affected hand was like before an injury. It may have had its own previous injury, osteoarthritis, weakness or an unusual pattern of use. That is why side-to-side comparison is combined with the history, sensory examination, movement assessment and strength testing. See also: Why Does an Orthopaedic Examination Test Muscle Strength?

What else is worth mentioning besides which hand you write with?

It is useful to say which hand you use for work, sport and particular tasks, because dominance can depend on the activity. Mention previous injuries to either arm, operations, limitations that were already present before the current problem and whether symptoms affect one side or both. This context helps assess the function of the individual person rather than comparing them only with a simplified rule.

Sources

• Foley RCA, Callaghan DH, Forman GN, et al. A comprehensive scoping review and meta-analysis of upper limb strength asymmetry. Scientific Reports. 2025;15:4636. DOI: 10.1038/s41598-025-87413-w; PMID 39920213.
• Cuyul-Vásquez I, Castillo-Vejar L, Garrido-Muñoz N, et al. One third of people exert greater handgrip strength with their non-dominant hand. Scientific Reports. 2026;16:1040. DOI: 10.1038/s41598-025-30659-1; PMID 41353458.

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Content prepared by: Tomasz Poboży - orthopaedic surgeon.