Design and analysis of testing mechanism for upper limb muscle strength training devices

ObjectiveTo address the issues of high subjective dependency and poor adaptability in the parameter measurement of existing upper limb muscle strength training devices, a testing mechanism was designed to adapt to two types of upper limb muscle strength training devices (pulling and pressing), achieving high-precision measurement of training parameters to meet the needs of precise training in fitness and medical rehabilitation fields.MethodsFirstly, two dedicated adapters were used to configure the testing mechanism with the two devices into R-S-S-P type and R-P-R-P type spatial four-bar mechanisms, respectively, to ensure diverse adaptability. Secondly, the velocity parameters and force parameters of the mechanism under isokinetic and isotonic modes were derived, and kinematics and dynamic models were established. Thirdly, simulations of the parameter measurement by the testing mechanism on the two devices were conducted under both isokinetic and isotonic modes. Finally, a test platform was built, and the calibration of the testing mechanism and the device parameter measurement tests were completed.ResultsThe simulation results are in good agreement with the theoretical analysis results; the measured velocity values in the tests are basically consistent with the set values, and the impedance force values after calibration are also basically consistent with the set values, which verify the high precision and reliability of the parameter measurement of the testing mechanism.