Biosignals Laboratory, School of Engineering, RMIT University, GPO Box 2476, Melbourne, VIC, Australia.
Med Biol Eng Comput. 2018 Aug;56(8):1413-1423. doi: 10.1007/s11517-018-1788-1. Epub 2018 Jan 16.
This study describes a new model of the force generated by tibialis anterior muscle with three new features: single-fiber action potential, twitch force, and pennation angle. This model was used to investigate the relative effects and interaction of ten age-associated neuromuscular parameters. Regression analysis (significance level of 0.05) between the neuromuscular properties and corresponding simulated force produced at the footplate was performed. Standardized slope coefficients were computed to rank the effect of the parameters. The results show that reduction in the average firing rate is the reason for the sharp decline in the force and other factors, such as number of muscle fibers, specific force, pennation angle, and innervation ratio. The fast fiber ratio affects the simulated force through two significant interactions. This study has ranked the individual contributions of the neuromuscular factors to muscle strength decline of the TA and identified firing rate decline as the biggest cause followed by decrease in muscle fiber number and specific force. The strategy for strength preservation for the elderly should focus on improving firing rate. Graphical abstract Neuromuscular properties of Tibialis Anterior on force generated during ankle dorsiflexion.
本研究描述了一种新的胫骨前肌产生力的模型，具有三个新特征：单纤维动作电位、单次收缩力和羽状角。该模型用于研究十种与年龄相关的神经肌肉参数的相对影响和相互作用。在足底产生的神经肌肉特性和相应模拟力之间进行回归分析（显著水平为 0.05）。计算标准化斜率系数以对参数的影响进行排序。结果表明，平均放电率的降低是导致力量急剧下降的原因，其他因素，如肌纤维数量、比肌力、羽状角和神经支配比。快肌纤维比例通过两个显著的相互作用影响模拟力。本研究对 TA 肌肉力量下降的神经肌肉因素的个体贡献进行了排序，发现放电率下降是最大的原因，其次是肌纤维数量和比肌力的减少。老年人的力量保持策略应侧重于提高放电率。
