Motor time of the rectus femoris during passive movements

Motor time (MT) of 10 normal subjects were examined in three conditions: 1) during passive flexion of the knee (PFLX), 2) during passive extension (PEXT), and without passive movement (STAT). Compared to STAT, MTs of PFLX and PEXT were significantly long. MT tended to be shorter, though insignificant statistically, in PFLX than in PEXT. In conclusion, passive movements are influential in changing the physical state of the muscle including both series-elastic and contractile components.