#Muscle synergy hypothesis serial

Quantitative results of patients suggest that maximum muscle tension and activation level of muscle synergy temporal patterns may reflect the effectiveness of subacute stroke rehabilitation.

#Muscle synergy hypothesis serial

Serial STS measurements were conducted with four post-stroke patients during their subacute rehabilitation stay (137 ± 22 days) in the hospital. The proposed joint torque-based method was also compared with the common static optimization based on squared muscle activation and showed higher simulation accuracy overall. The novel method was validated against MVC-normalized EMG data from eight healthy participants, and it retained muscle activation amplitude differences for inter- and intra-subject comparisons. Next, upon method validation, we apply it to quantify changes in muscle tension and muscle synergy activation levels in STS motor control units for patients in subacute stroke rehabilitation. Here, focusing on the paretic side, we first propose a novel, joint torque-based normalization method that incorporates musculoskeletal modeling, forward dynamics simulation, and mathematical optimization. However, current normalization methods using maximum voluntary contraction (MVC) or within-task peak/mean EMG may not be feasible when MVC cannot be obtained from stroke survivors due to motor paralysis and the subject of comparison is EMG amplitude. To better enable a longitudinal investigation into a patient's muscle activation changes during rehabilitation or an inter-subject comparison, EMG normalization is usually applied. Although some qualitative findings are available, it is not clear if and how muscle activation amplitude-related biomechanical attributes may quantitatively reflect during subacute stroke rehabilitation. Muscle activation amplitude, related to muscle tension and muscle synergy activation levels, is one of the defining EMG features that reflects post-stroke motor functioning and motor impairment. Post-stroke patients exhibit distinct muscle activation electromyography (EMG) features in sit-to-stand (STS) due to motor deficiency. 6Department of Rehabilitation, University of Toyama, Toyama, Japan.5College of Information Technology, United Arab Emirates University, Al Ain, United Arab Emirates.4Department of Physical Therapy, Saitama Prefectural University, Saitama, Japan.3RIKEN Center for Brain Science, Aichi, Japan.2Department of Information Science and Electrical Engineering, Kyushu University, Fukuoka, Japan.1Department of Precision Engineering, The University of Tokyo, Tokyo, Japan.Yamasaki 4 Moeka Yokoyama 3 Fady Alnajjar 3,5 Noriaki Hattori 6 Kouji Takahashi 7 Takanori Fujii 7 Hironori Otomune 7 Ichiro Miyai 7 Atsushi Yamashita 1 Hajime Asama 1 Ruoxi Wang 1 Qi An 2 * Ningjia Yang 3 Hiroki Kogami 1 Kazunori Yoshida 1 Hiroshi Yamakawa 1 Hiroyuki Hamada 1 Shingo Shimoda 3 Hiroshi R.