The handgrip strength threshold of 16 kg discriminates successful rehabilitation: A prospective short-term study of 258 women with hip fracture

Aim: In 2019 the European Working Group on Sarcopenia in Older People (EWGSOP) indicated weakness as the key characteristic of sarcopenia and released the threshold of 16 kg for handgrip strength to define weakness in women. We aimed to externally validate the 16 kg cut-off point for predicting functional recovery in 258 women with subacute hip fracture admitted to our rehabilitation ward. Methods: We assessed handgrip strength by a hand-grip Jamar dynamometer at admission to inpatient rehabilitation and functional ability in activities of daily living by the Barthel index at the end of the rehabilitation course. Successful rehabilitation was defined with a Barthel index score ≥85 and highest possible recovery with a Barthel index effectiveness = 100 %. Results: A handgrip strength ≥16 kg significantly predicted both successful rehabilitation (χ2 = 23.5, P < 0.001) and highest possible recovery (χ2 = 31.05, P < 0.001). For the women with a handgrip strength ≥16 kg, the odds ratios to gain successful rehabilitation and highest possible recovery were 2.68 (95 % CI from 1.19 to 6.04; P = 0.018) and 2.81 (95 % CI from 1.47 to 5.37; P = 0.002), after adjustment for Barthel index scores before rehabilitation, age, hip-fracture type (either medial or lateral), cognitive impairment and 25-hydroxyvitamin D levels. Conclusion: Our results provide an external validation of the 16 kg handgrip strength threshold recently released to discriminate functional outcomes: it significantly predicted the short-term ability to perform activities of daily living after hip fracture in women.