Muscle recruitment and coordination during upper-extremity functional tests

Abstract

Performance-based tests, such as the Jebsen Taylor Hand Function Test or Chedoke Arm and Hand Activity Inventory, are commonly used to assess functional performance after neurologic injury. However, the muscle activity required to execute these tasks is not well understood, even for unimpaired individuals. The purpose of this study was to evaluate unimpaired muscle recruitment and coordination of the dominant and non-dominant limbs during common clinical tests. Electromyography (EMG) recordings from eight arm muscles were monitored bilaterally for twenty unimpaired participants while completing these tests. Average signal magnitudes, activation times, and cocontraction levels were calculated from the filtered EMG data, normalized by maximum voluntary isometric contractions (MVICs). Overall, performance of these functional tests required low levels of muscle activity, with average EMG magnitudes less than 6.5% MVIC for all tests and muscles, except the extensor digitorum, which had higher activations across all tasks (11.7 ± 2.7% MVIC, dominant arm). When averaged across participants, cocontraction was between 25 and 62% for all tests and muscle pairs. Tasks evaluated by speed of completion, rather than functional quality of movement demonstrated higher levels of muscle recruitment. These results provide baseline measurements that can be used to evaluate muscle-specific deficits after neurologic injury and track recovery using common clinical tests.

A calibrated database of kinematics and EMG of the forearm and hand during activities of daily living

“…When considering muscle activity vs. ADL, minor muscle activity was generally observed in all the ADL. This fact agrees with the fact that minimal muscle force is required to perform ADL 26 , as can be observed in Fig. 9, subplot A, where greater activity is shown during reaching (to place the hand to grasp) than during manipulation, as the tasks performed were low demanding.…”

“…Some variability was noted when considering muscle activity in relation to the recorded spot. In particular, spots 5 (finger extensors) and 6 (wrist extensors) presented the highest median values, which agrees with the fact that these muscles are the most active ones while performing ADL 26 . An agreement was also found with the kinematic data as the wrist seemed to work more in extension.…”

Assessment of Dry Epidermal Electrodes for Long-Term Electromyography Measurements

“…To quantify and compare the signal quality of the ESS and Delsys electrodes, each subject performed muscle activation tests, including MVICs and dynamic range of motion tests, as well as functional tests including the Jebsen Taylor Hand Function Test [ 38 ] and Box & Block Test [ 39 ]. Muscle activation tests allowed us to evaluate the similarity of sEMG measurements and signal quality between the Delsys and ESS electrodes for a large range of sEMG values, while the functional tests helped determine the similarity of sEMG measurements and signal quality between electrodes for clinically-relevant tests that mimic movements performed in everyday life, which tend to have smaller sEMG amplitudes [ 40 ]. The Jebsen Taylor and the Box & Block Tests were chosen for their clinical relevance as both are standard unimanual tests commonly used clinically to assess individuals with neurologic injuries.…”

Altered visual feedback from an embodied avatar unconsciously influences movement amplitude and muscle activity

“…We measured participants’ motor performance by recording both the actual position of the real arm using a motion tracking system and electromyographic (EMG) activity of the right biceps muscle. Surface EMG recordings allowed us to evaluate muscle recruitment, having previously been shown to be efficient for monitoring muscle activity during dynamic tasks 18 .…”