The relationship between hand prehensile strength, clinical activity and functional capacity in patients with rheumatoid arthritis

Nueva publicación en conjunto de nuestros compañeros de la red, los doctores Iris Paola Guzmán (México) y Daniel Jérez (Chile).

Abstract

Background The hand is an anatomical structure with a large number of joints; its prehensile grasp capability constitutes a highly specialised biomechanical function. In rheumatoid arthritis (RA), the structures of the joint are damaged by the characteristic inflammatory process1 The Disease Activity Score (DAS28) considers twenty hand joints in the evaluation of rheumatoid arthritis (RA). While the Health Assessment Questionnaire (HAQ) disability index (DI) (HAQ-DI) is the most frequently used instrument for measuring self-reported physical function in rheumatoid arthritis and considers the ability to dress and groom, get up, eat, hygiene, reach, grasp, situations in which the functional capability of the hand is crucial.

Objectives To assess the relationship between hand prehensile strength, the DAS28 index and HAQ-DI score in patients with diagnosis of RA.

Methods The prehensile strength was obtained by the dynamometry method from 105 AR patients, the maximum strength levels in the dominant and non-dominant hand were considered. The Disease Activity Score in 28 joints using the erythrocyte sedimentation rate (DAS28-ESR) and HAQ-DI were recorded.

Results The maximum prehensile strength, on average, was 14 kg, and the weak force category was more prevalent. The prehensile strength of both hands was negatively correlated with the HAQ-DI score and DAS28 index. In an adjusted logistic regression model, the ”weak” strength category of the non-dominant hand was associated with “moderate clinical activity” in the DAS28 score (OR=8.59, p=0.02), while the category of ”weak” strength of the dominant hand was associated with the presence of ”some difficulty” of HAQ-DI score (OR=4.75, p=0.10).

Conclusions The decrease in prehensile strength represents a marker associated with the DAS28 index and HAQ-DI score in the patient with RA, regardless of age, muscle mass, total fat or body mass. The measurement of the prehensile strength can be a useful and inexpensive tool to be considered in the clinical evaluation of the RA.

Reference [1] Janet L Poole. Hand Function in Rheumatoid Arthritis. Mehmet Tuncay Duruöz A Practical Guide to Assessment. Springer. 2014. [ISBN:978–1–4614–9448–5]

http://dx.doi.org/10.1136/annrheumdis-2018-eular.7534