Motor units with a pulse-to-noise ratio (13) <30 dB and/or with discharges separated by >2 s were discarded from further analysis. The individual motor unit discharge timings were summed to generate a cumulative spike train (CST).
力的大小主要通过两种途径改变：
- 运动单元的放电频率：运动单元的放电频率越高，产生的力越大
- 运动单元的募集数量：募集的运动单元数量越多，产生的力越大