Reference Values of Grip Strength, Prevalence of Low Grip Strength, and Factors Affecting Grip Strength Values in Chinese Adults

Objectives: The objectives of this study were to update the reference values of grip strength, to estimate the prevalence of low grip strength, and to examine the impact of different aspects of measurement protocol on grip strength values in Chinese adults. Design, Setting, and Participants: A cross-sectional survey of Chinese men (n = 714) and women (n = 4014) aged 18-102 years was undertaken in different community settings in Hong Kong. Measurements: Grip strength was measured with a digital dynamometer (TKK 5401 Grip-D; Takei, Niigata, Japan). Low grip strength was defined as grip strength 2 standard deviations or more below the mean for young adults. The effects of measurement protocol on grip strength values were examined in a subsample of 45 men and women with repeated measures of grip strength taken with a hydraulic dynamometer (Baseline; Fabrication Enterprises Inc, Irvington, NY), using pair t-tests, intraclass correlation coefficient, and Bland and Altman plots. Results: Grip strength was greater among men than among women (P < .001) and the rate of decline differed between sexes (P < .001). The prevalence of low grip strength also increased with age, reaching a rate of 16.5% in men and 20.6% in women aged 65+. Although the TKK digital dynamometer gave higher grip strength values than the Baseline hydraulic dynamometer (P < .001), the degree of agreement between the 2 dynamometers was satisfactory. Higher grip strength values were also observed when the measurement was performed with the elbow extended in a standing position, compared with that with the elbow flexed at 90 degrees in a sitting position, using the same dynamometer (P < .05). Conclusions: This study updated the reference values of grip strength and estimated the prevalence of low grip strength among Chinese adults spanning a wide age range. These findings might be useful for risk estimation and evaluation of interventions. However, grip strength measurements should be interpreted with caution, as grip strength values can be affected by type of dynamometer used, assessment posture, and elbow position. (C) 2017 AMDA - The Society for Post-Acute and Long-Term Care Medicine.