Accuracy of older adults in judging self-generated elbow torques during multi-joint isometric tasks

Abstract

Successful execution of daily activities requires accurate perception of the torques one generates about multiple joints. even so, previous studies are mostly limited to an individual's perception when torques are generated about a single joint. consequently, this study investigates how accurately individuals judge torques at their arm during a multi-joint task. The accuracy of fifteen right-hand dominant participants (age: 60 ± 10 years) in matching isometric elbow torques, within the same arm, was quantified during single-and/or multi-joint tasks. Participants generated and matched elbow torques when the shoulder was: (1) not abducted (single-to-single-joint), (2) abducted (multi-to-multijoint), and (3) abducted and then not abducted (multi-to-single-joint). The constant error for the multito-single-joint condition (dominant: 6.9 ± 5.9 Nm, non-dominant: 6.0 ± 5.5 Nm) was greater than that for the single-to-single-joint condition (dominant: 2.7 ± 3.1 Nm, non-dominant: 3.4 ± 2.8 Nm) (p < 0.001) and multi-to-multi-joint condition (dominant: 3.0 ± 2.8 Nm, non-dominant: 3.9 ± 2.7 Nm) (p < 0.001). The constant error for the multi-to-multi-joint condition did not significantly differ from that of the single-to-single-joint condition (p = 0.780). Findings indicate that in older adults the perception of a self-generated torque during a 2-degree-of-freedom (DOF), multi-joint task is largely influenced by the motor commands associated with the 2-DOF task and is not specific to the DOF at each joint.

The Impact of Multicomponent Exercise Protocols Order on the Maximum Voluntary Contraction of Older Women

“…Elbow flexor strength serves as a reliable indicator of the ability to efficiently perform multi-joint movements in daily activities, such as grasping and moving objects [42]. Despite not evaluating this specific variable, a possible adaptation recurring during strength gains is neural activation, which plays a role in the EF's contractile capacity, contributing to coordination during daily tasks [42]. Unlike the findings for knee extensor (KE) and knee flexor (KF) MVIC, we observed smaller effect sizes in EF MVC after the intervention.…”

“…This discrepancy may be partially explained by the fact that the MCT program did not provide a similar stimulus to the upper limbs as it did to the lower limbs. Cai et al [42] suggest that MCT interventions should be designed to equalize or at least increase the stimulus for upper limb strength development and the efficient performance of activities of daily living [42]. In contrast, the CG experienced significant and moderate effect size decreases in EF MVC between the first and second evaluation moments.…”