Hand grip strength (HGS) is used for the diagnosis of sarcopenia and frailty. Several factors have been shown to influence HGS values during measurement. Therefore, variations in the protocols used to assess HGS, as part of the diagnosis of sarcopenia and frailty, may lead to the identification of different individuals with low HGS, introducing bias. The aim of this systematic review is to gather all the relevant studies that measured HGS to diagnose sarcopenia and frailty and to identify the differences between the protocols used. A systematic review was carried out following the recommendations of The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement. PubMed and Web of Science were systematically searched, until August 16, 2016. The evidence regarding HGS measurement protocols used to diagnose sarcopenia and frailty was summarised and the most recent protocols regarding the procedure were compared. From the described search 4393 articles were identified. Seventy-two studies were included in this systematic review, in which 37 referred to sarcopenia articles, 33 to frailty and two evaluated both conditions. Most studies presented limited information regarding the protocols used. The majority of the studies included did not describe a complete procedure of HGS measurement. The high heterogeneity between the protocols used, in sarcopenia and frailty studies, create an enormous difficulty in drawing comparative conclusions among them.

Some dynamometers previously tested in healthy adults showed variable degrees of practicality, weight and ergonomics. More practical models could also be used as a more suitable tool in gerontological field and clinical studies. The purpose of the present study was to evaluate the reliability of the measurements and the performance of hand grip strength dynamometers in the elderly. Crosssectional study. A retirement home and a social day care centre for old people in Porto, Portugal. The accuracy of four static grip strength dynamometers (Smedlay’s® Hand, Sammons Preston Rolyan® Bulb, Eisenhut® and the Jamar® Hydraulic Hand) was first tested in laboratory. The grip strength of fifty-five elderly individuals 65–99 years was measured with the four dynamometers and the Jamar® Hydraulic Hand which was used as the comparison dynamometer. The accuracy of the four dynamometers measurements compared to known forces was excellent (r > 0.96). A strong association between the measurements obtained by the Jamar® Hydraulic and the other instruments evaluated was found (r > 0.77) but significant differences between the mean hand grip strength values evaluated with the Jamar® Hydraulic and each one of the other dynamometers were found. The Bland and Altman plots confirmed that none of the three dynamometers reflects a good agreement with the Jamar® Hydraulic. All four dynamometers showed excellent results regarding their laboratory tested accuracy. However, their application among elderly people rendered very different results. The Smedlay’s® results’ were closer to the Jamar® Hydraulic, though none of these three dynamometers produced comparable results to the Jamar® Hydraulic.