(44) Electronic Handgrip Dynamometry and Accelerometry Derived Muscle Function are Associated with Lower Extremity Strength in Older Adults

Purpose: Conventional handgrip dynamometers only allow for the feasible measurement of overall muscle strength. Electronic handgrip dynamometry and accelerometry is a novel collection method that allows for the opportunity to ascertain more attributes of muscle function beyond strength capacity while also preserving feasibility. However, the role of this new muscle function collection mode on lower extremity muscle strength remains unknown. We sought to determine the associations between electronic handgrip dynamometry and accelerometry derived muscle function on lower extremity strength in older adults. Methods: We utilized an observational design for this investigation. Data were collected from n=121 generally healthy adults aged at least 65-years (age: 70.8±4.8 years; 67.0% female). Electronic handgrip dynamometers and accelerometers were used to measure individual attributes of muscle function: strength, submaximal control, rate of force development, and neuromuscular steadiness. Isokinetic dynamometry was used to collect knee extension strength. Linear regression models were used for the analyses. Results: Strength (β=2.63; p< 0.01), sub-maximal control (β=-1.22; p< 0.01), rate of force development (β=0.51; p< 0.01), and neuromuscular steadiness (β=0.62; p< 0.01) were each associated with lower extremity strength. Conclusions: Electronic handgrip dynamometry and accelerometry derived strength, sub-maximal control, rate of force development, and neuromuscular steadiness were linked with lower extremity strength. These findings suggest that a signal exists for using electronic handgrip dynamometry and accelerometry to serve as indicators for whole body muscle function. However, more research is needed to examine how each aspect of muscle function as measured by electronic handgrip dynamometry and accelerometry is linked to such individual aspects in the lower extremities. Practical Applications: Handgrip dynamometry is a feasible method for collecting overall muscle strength, especially in older populations. Sports medicine practitioners are encouraged to utilize handgrip dynamometers to assess strength capacity as appropriate. Electronic handgrip dynamometers and accelerometers provide advancements in methods and instruments, which may have promise for providing more insights regarding muscle health than conventional handgrip dynamometers. Acknowledgements: Research reported was supported by the National Institute on Aging of the National Institutes of Health under Award Number R15AG072348. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.