Bara Alsalaheen1, Ryan Bean2, Andrea Almeida3, James Eckner4, Matthew Lorincz3. 1. Department of Physical Therapy, University of Michigan-Flint, Flint, MI, USA; Department of Neurology, University of Michigan, Ann Arbor, MI, USA; Michigan NeuroSport, Michigan Medicine, Ann Arbor, MI, USA. Electronic address: Alsalahe@umflint.edu. 2. Department of Physical Therapy, University of Michigan-Flint, Flint, MI, USA. 3. Department of Neurology, University of Michigan, Ann Arbor, MI, USA; Michigan NeuroSport, Michigan Medicine, Ann Arbor, MI, USA. 4. Department of Physical Medicine and Rehabilitation, University of Michigan, Ann Arbor, MI, USA; Michigan NeuroSport, Michigan Medicine, Ann Arbor, MI, USA.
Abstract
BACKGROUND: The majority of studies examining the role of cervical muscles on head-neck kinematics focused on musculoskeletal attributes (e.g. strength). Cervical neuromuscular response to perturbation may represent a divergent construct that has not been examined under various perturbation conditions. This study examined the association between cervical musculoskeletal attributes and cervical neuromuscular response of the sternocleidomastoid (SCM) to perturbation. Furthermore, this study examined the effect of anticipation and preload on the SCM neuromuscular response. METHODS: Nineteen participants completed measurement of SCM muscle size, cervical flexion maximal voluntary isometric contraction, and the neuromuscular response of the SCM to cervical perturbation. Cervical perturbation was delivered by dropping a 1.59 kg mass from a loading apparatus. The impulsive load was delivered under four conditions: (1) Anticipated perturbation with no preload (A-NP), (2) Unanticipated perturbation with no preload (U-NP), (3) Anticipated perturbation with preload (A-P), and (4) Unanticipated perturbation with preload (U-P). RESULTS: None of the cervical musculoskeletal attributes were correlated with the SCM cervical neuromuscular response. This study demonstrated significant effect of preloading and anticipation on baseline EMG amplitude and EMG onset latency for the SCM. Furthermore, there was a significant effect of preloading on average EMG response amplitude for the SCM. DISCUSSION: The findings of this study indicate that cervical neuromuscular response of the SCM is different from musculoskeletal attributes and is influenced by perturbation conditions. These findings provide conceptual support to examine the neuromuscular response of the SCM in mitigating head-neck kinematics.
BACKGROUND: The majority of studies examining the role of cervical muscles on head-neck kinematics focused on musculoskeletal attributes (e.g. strength). Cervical neuromuscular response to perturbation may represent a divergent construct that has not been examined under various perturbation conditions. This study examined the association between cervical musculoskeletal attributes and cervical neuromuscular response of the sternocleidomastoid (SCM) to perturbation. Furthermore, this study examined the effect of anticipation and preload on the SCM neuromuscular response. METHODS: Nineteen participants completed measurement of SCM muscle size, cervical flexion maximal voluntary isometric contraction, and the neuromuscular response of the SCM to cervical perturbation. Cervical perturbation was delivered by dropping a 1.59 kg mass from a loading apparatus. The impulsive load was delivered under four conditions: (1) Anticipated perturbation with no preload (A-NP), (2) Unanticipated perturbation with no preload (U-NP), (3) Anticipated perturbation with preload (A-P), and (4) Unanticipated perturbation with preload (U-P). RESULTS: None of the cervical musculoskeletal attributes were correlated with the SCM cervical neuromuscular response. This study demonstrated significant effect of preloading and anticipation on baseline EMG amplitude and EMG onset latency for the SCM. Furthermore, there was a significant effect of preloading on average EMG response amplitude for the SCM. DISCUSSION: The findings of this study indicate that cervical neuromuscular response of the SCM is different from musculoskeletal attributes and is influenced by perturbation conditions. These findings provide conceptual support to examine the neuromuscular response of the SCM in mitigating head-neck kinematics.
Authors: Mohammad Homayounpour; Nicholas G Gomez; Alexandra C Ingram; Brittany Coats; Andrew S Merryweather Journal: Ann Biomed Eng Date: 2021-12-01 Impact factor: 3.934
Authors: Mohammad Homayounpour; Nicholas G Gomez; Anita N Vasavada; Andrew S Merryweather Journal: Ann Biomed Eng Date: 2021-03-25 Impact factor: 3.934