Purpose: People with Parkinson’s disease (PD) have impaired force production, which is associated with decreased mobility and falls risk. Reliable measurement of force production is important. Design: A repeated-measures, intra- and inter-rater reliability study was undertaken. Participants: 24 people with mild PD were measured by one or two raters. Outcome measures: Isometric force of the major upper and lower limb muscle groups was measured using hand-held dynamometry. Results: Fourteen participants were measured by the same rater on two occasions to determine intra-rater reliability. Ten participants were measured on two occasions by two different raters to determine inter-rater reliability. The intra-rater reliability of hand-held dynamometry was excellent in every muscle group, except the dorsiflexors. Intra-rater reliability was highest when measuring wrist extensors (ICC(2,1) = 0.98, 95% CI: 0.94 to 0.99) and lowest when measuring ankle dorsiflexors (ICC(2,1) = 0.87, 95% CI: 0.43 to 0.97). Inter-rater reliability was variable ranging from poor (wrist flexors: ICC(2,2) = -0.15, 95% CI: -1.14 to 0.60) to excellent (grip strength: ICC(2,2) = 0.97, 95% CI: 0.88 to 0.99). Conclusion: Hand-held dynamometry has good to excellent intra-rater reliability, but poor inter-rater reliability, for measuring force in the upper and lower limb in people with mild PD.
We would like to acknowledge the people with PD who kindly gave up their time to participate in this study.
Boom M, Preston E, Salmon R, Ada L, Flynn A. Reliability of Hand-Held Dynamometry for Measuring Force Production in People with Parkinson’s Disease. The Internet Journal of Allied Health Sciences and Practice. 2023 Jan 04;21(1), Article 3.