A kinematic and electromyographic study of grip in extension in a clinical setting

Grip, including grip in extension, is an essential element in human beings. The functional evaluation scales of the hand require a greater number of objective variables in order to offer an overall perspective. Devices such as surface electromyography and inertial sensors can be used in evaluation and tasks. Such equipment can lead to new variables for analysis and offer different approaches for treatment.

Six participants were selected randomly from a sample of healthy population. Each participant made the grip in extension, which was parameterized in real time. This movement was analyzed and recorded in a synchronized manner with surface electromyography and accelerometer-type inertial sensors in the hand.

After analyzing and processing the data, it was possible to detect five phases within the movement thanks to in-depth analysis of the module vector of the index finger along with electromyography of the musculature of the first dorsal interosseous.

Parameterization is possible in real time for the grip in extension based on surface electromyography and accelerometer, offering new analysis variables on hand operation while providing a suitable complement to standardized assessments. Implications for Rehabilitation The use of surface electromyography and accelerometry in the arm synchronously, allows clinicians to identify new intervention and treatment variables. The protocol developed can be used in clinical practice because it is non-invasive, the enabled devices do not cause damage on the subject. According to the results, the muscles of the hypothenar region and the first dorsal interosseous have greater activation in the hand during grip extension. The wrist extensor muscles and flexor carpi ulnaris have more activation during the approach phase to grip. These are the muscles that should be prioritized for rehabilitation. The variation of the acceleration allows you to differentiate between the phases of rest and movement of the hand. If the variation of the acceleration at rest is higher than 0.3g, this could indicate the presence of abnormal movements or tremor.