Motor control strategies during unpredictable force control tasks in humans

Abstract

Background There are fundamental similarities and differences between the jaw and hand motor systems. However, it is unclear how the two systems respond to unpredictable task demands. Objective To investigate and compare the force control of the jaw motor system (OMS) and the hand motor system (HMS) during unpredictable load changes. Methods Seventeen healthy adults (24.0 ± 4.3 years) performed two standardised force control tasks (OMS and HMS). During the OMS, the participants asked to bite and pull a force transducer with the front teeth. While during HMS they pinched and pulled the same force transducer with their index and thumb fingers. Series of loads were added to a string attached to the transducer in an unpredictable (sequential and non‐sequential) manner. The entire force profile during the task was divided into “initial” and “latter” segments. The force control was analysed and compared between the OMS and HMS in terms of peak force during the initial segment and holding force and force variability during the latter segment. Results The peak force, holding force and force variability were higher for the OMS than the HMS (P < .001). However, there were no differences in the peak force, holding force or force variability between the sequential and non‐sequential load changes (P > .05). Conclusions The results showed that unpredictable load changes did not affect the force control during the motor control task. This study suggests that both the motor systems are optimised in performing simple motor control tasks and are rather resilient to motor unpredictability.

Effect of apical microsurgery on force regulation of incisor teeth during unpredictable force control task

“…27 Previous studies have assessed oral motor control in participants who have healthy teeth from various age groups during unpredictable force tasks. 8,9 These studies observed that the oral motor control and force regulation for children and adults are similar. There are no studies, however, that have examined how different dental interventions impact oral motor control during unpredictable force control tasks.…”

“…The detailed description of the task and the specifications of the apparatus are described in the previous studies. 8,9 In brief, the apparatus consisted of a custom-built strain gauge-based force transducer (Department of Integrative Medical Biology, Umeå University,) resting on a platform and tied with a string (0.25 mm diameter and 5 kg strength; Master Line Kayoba; Jula,). The string passes through a pulley and is terminated in a metal hook, where different standardised metallic loads (Viktsats; Sagitta Pedagog AB,) could be attached.…”

“…6 Sensory information plays a critical role in the regulation of forces and movements necessary for oral motor activities such as biting and chewing. [7][8][9][10] Previous studies have shown an impaired force control due to disruption or disturbance of such sensory information from the afferent neurons that surrounded the teeth roots. [11][12][13][14] The impaired force control was evident in the higher 'holding' forces in a standardised biting task.…”

“…Previous studies have investigated the effect of unpredictable load demands on motor control strategies in children and adults. 8,9 However, there is limited information on motor control strategies and force regulation during unpredictable load demands in endodontically treated teeth. 7 The goals of AMS treatment are not only restricted to the absence of signs and symptoms or resolution of apical periodontitis, 5 but also extended to preservation of tooth function and patient satisfaction.…”

Cognitive changes and neural correlates after oral rehabilitation procedures in older adults: a protocol for an interventional study

“…Contemporary orofacial neuroscience [60] related research has emphasized the importance of sensorimotor regulation [61][62][63][64][65][66][67][68][69][70] and adaptation to the altered oral environment during biting [64,[71][72][73][74] and chewing behaviors [71]. Further, recent studies have discussed the significance of retaining natural dentition and optimizing oral functions in people with a dental prosthesis [62,63,[75][76][77][78].…”