Handgrip strength in fibromyalgia 2020


Senior Member
Force-time curve features of handgrip strength in fibromyalgia syndrome

The aim of this study was to compare the handgrip strength (HGs), assessed with a cylindrical-shape grip device, of fibromyalgia syndrome (FM) patients with healthy subjects and to demonstrate the relationship between HGs characteristics and disease severity.

Consecutive female patients with FM were enrolled and compared to a group of healthy women.

The correlations between HGs curve characteristics and disease severity indices were studied through the Spearman’s rho correlation coefficients (rho). The HGs threshold distinguishing the FM presence was determined using the receiver operating characteristic (ROC) curves analysis.

Multivariate regression analysis was used in order to assess the contribution of covariates on the HGs. 110 patients (mean age 53.8 ± 12.4 years) and 111 healthy controls have been enrolled.

Altogether all parameters related to the analysis of HGs were worse in patients with FM.

The HGs cut-off distinguishing the presence of a FM was 14.2 Kg.

A negative correlation was found between disease severity indices and peak force (p < 0.001).

Factors significantly associated with HGs area under the curve (AUC) in multivariate analysis were the Widespread Pain Index (WPI) (p = 0.003) and the revised Fibromyalgia Impact Questionnaire (FIQR) (p = 0.016).

HGs is reduced in female FM patients and is inversely related to disease severity. The force-time curves analysis may be used as a complementary tool in the FM assessment and monitoring.


Fibromyalgia syndrome (FM) is a multi-symptom disorder, characterized mainly by chronic widespread musculoskeletal pain, chronic fatigue, sleep disturbance, symptoms of cognitive impairment, and activity limitations, the etiology of which is still to be clarified1.

The physical fitness is globally reduced over the course of FM and under this term are included multiple domains, in particular muscle strength, aerobic activity, balance and flexibility: the limitations of one or more of these aspects determine a functional limitation2,3.

Adequate muscle strength is obviously necessary to perform all the usual actions of daily life4,5,6. In female patients with FM, a strength deficit of 20% to 36% is documented compared to healthy women7. The reduction in muscle strength in women with FM results in a deterioration in the quality of life (QoL)8.
Handgrip strength (HGs), as a substitute for overall muscle strength, is related to physical fitness9,10.

HGs is traditionally measured as the maximum force that can be generated by each hand. This parameter is used to assess the degree of hand deterioration in the FM. However, peak force measurement alone does not take into account other hand strength characteristics such as force generation speed, sustainability, and grip force variability.

A more accurate description of HGs is certainly provided by the force-time (FeT) curve analysis. The FeT curve can be used to assess effort sincerity and distinguish between sincere effort and false weakness11. Through the analysis of the FeT curve it is possible to reveal peak force, mean force, total grip time, area under the curve, and variability of the curve plateau region12.
To the best of our knowledge, such kind of assessment has never been conducted in FM patients.

On the basis of these considerations, the objective of this study was to explore the FeT curve analysis of HGs, using a cylindrical-shape grip device, in patients suffering from FM compared to healty subjects.