Are hand-held dynamometers good enough for strength testing?

A systematic review and meta-analysis examined whether hand-held dynamometers are reliable and valid for measuring hip, knee and ankle strength in healthy adults. It pooled 18 studies, sixteen looking at reliability and ten at validity, with four contributing to the meta-analysis. Methodological quality was graded with QAREL and QUADAS-2, standard appraisal checklists for reliability and diagnostic accuracy studies, and certainty with GRADE. It was funded by a government science agency and registered on PROSPERO.

Hand-held dynamometers held up. Reliability across raters and within raters ranged from moderate to very high, and validity against isokinetic dynamometry, the expensive gold standard, ranged from moderate to near perfect. The pooled meta-analytic estimate, strongest for hip and knee movements, pointed to high to very high reliability with minimal measurement error.

Two caveats sit in the detail. The strongest pooled evidence is for hip and knee rather than ankle, and the whole review is in healthy adults, not patients with pathology. The authors are clear that evaluator proficiency and a standardised protocol materially affect the numbers.

This is permission to trust the tool you can actually afford. If isokinetic testing is impractical, which it can be in some private clinics, a hand-held dynamometer is a defensible way to put a number on hip and knee strength for return-to-run decisions, rehab progression, orthotic review and exercise physiology programming. Objective beats “feels a bit weaker on that side” every time, and it gives you something to re-test against.

Protocol is the catch. The validity in this review assumes standardised positioning, stabilisation and effort instructions. Pick one protocol, use the same one every time, and train anyone else in the clinic who picks up the device, because the moment your method drifts the reassessment stops meaning anything. Treat ankle numbers and any reading from a deconditioned or painful patient with more caution, since that sits outside where the evidence is strongest.

For hip and knee strength in clinic, a hand-held dynamometer is good enough, as long as your protocol is identical every time.

https://pubmed.ncbi.nlm.nih.gov/42016044/