title: Temporary Nerve Block at Selected Digits Revealed Hand Motor Deficits in Grasping Tasks.
abstract: Peripheral sensory feedback plays a crucial role in ensuring correct motor execution throughout hand grasp control. Previous studies utilized local anesthesia to deprive somatosensory feedback in the digits or hand, observations included sensorimotor deficits at both corticospinal and peripheral levels. However, the questions of how the disturbed and intact sensory input integrate and interact with each other to assist the motor program execution, and whether the motor coordination based on motor output variability between affected and non-affected elements (e.g., digits) becomes interfered by the local sensory deficiency, have not been answered. The current study aims to investigate the effect of peripheral deafferentation through digital nerve blocks at selective digits on motor performance and motor coordination in grasp control. Our results suggested that the absence of somatosensory information induced motor deficits in hand grasp control, as evidenced by reduced maximal force production ability in both local and non-local digits, impairment of force and moment control during object lift and hold, and attenuated motor synergies in stabilizing task performance variables, namely the tangential force and moment of force. These findings implied that individual sensory input is shared across all the digits and the disturbed signal from local sensory channel(s) has a more comprehensive impact on the process of the motor output execution in the sensorimotor integration process. Additionally, a feedback control mechanism with a sensation-based component resides in the formation process for the motor covariation structure.
authors.affiliation: Department of Physical Therapy, College of Staten Island, City University of New York Staten Island, NY, USA.
authors.forename: Aude
authors.initials: A
authors.lastname: Carteron
authors.affiliation: Department of Physical Therapy, College of Staten Island, City University of New York Staten Island, NY, USA.
authors.forename: Kerry
authors.initials: K
authors.lastname: McPartlan
authors.affiliation: Department of Physical Therapy, College of Staten Island, City University of New York Staten Island, NY, USA.
authors.forename: Christina
authors.initials: C
authors.lastname: Gioeli
authors.affiliation: Department of Physical Therapy, College of Staten Island, City University of New York Staten Island, NY, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Reid
authors.affiliation: Department of Physical Therapy, College of Staten Island, City University of New York Staten Island, NY, USA.
authors.forename: Matt
authors.initials: M
authors.lastname: Turturro
authors.affiliation: Emergency Medicine, Staten Island University Hospital Staten Island, NY, USA.
authors.forename: Barry
authors.initials: B
authors.lastname: Hahn
authors.affiliation: Emergency Medicine, Staten Island University Hospital Staten Island, NY, USA.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Benson
authors.affiliation: Department of Physical Therapy, College of Staten Island, City University of New YorkStaten Island, NY, USA; Ph.D. Program in Biology, Graduate School and University Center, City University of New YorkNew York, NY, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
keywords: anesthesia; anticipatory control; force; hand; moment; motor coordination; motor synergy