论文部分内容阅读
We studied the motor response to modifying the rate of application of sensory input to the human spinal cord during stepping. We measured the electromyographi c (EMG), kinematic and kinetic patterns of the legs during manually assisted or unassisted stepping using body weight support on a treadmill (BWST) in eight ind ividuals with spinal cord injury (SCI). At various treadmill speeds (0.27-1.52 m/s), we measured the EMG activity of the soleus (SOL), medial gastrocnemius (MG ), tibialis anterior (TA), medial hamstrings (MH), vastus lateralis (VL), rectus femoris (RF) and iliopsoas (ILIO); the hip, knee and ankle joint angles; the am ount of body weight support (BWS); and lower limb loading. The EMG amplitude and burst duration of the SOL, MG, TA, MH, VL, RF and ILIO were related to the step cycle duration during stepping using BWST. EMG mean amplitudes increased at fas ter treadmill speeds, and EMG burst durations shortened with decreased step cycl e durations. Muscle stretch of an individual muscle could not account for the EM G amplitude modulation in response to stepping speed. The effects on the EMG amp litude and burst duration were similar in subjects with partial and no detectabl e supraspinal input. We propose that the human spinal cord can interpret complex steprelated, velocity dependent afferent information to contribute to the neur al control of stepping.
We studied the motor response to modifying the rate of application of sensory input to the human spinal cord during stepping. We measured the electromyographi c (EMG), kinematic and kinetic patterns of the legs during manually assisted or unassisted stepping using body weight support on a At various treadmill speeds (0.27-1.52 m / s), we measured the EMG activity of the soleus (SOL), medial gastrocnemius (MG), tibialis anterior (BWST) in eight ind ividuals with spinal cord injury TA), medial hamstrings (MH), vastus lateralis (VL), rectus femoris (RF) and iliopsoas (ILIO); the hip, knee and ankle joint angles; the amount of body weight support (BWS); . The EMG amplitude and burst duration of the SOL, MG, TA, MH, VL, RF and ILIO were related to the step cycle duration during stepping using BWST. EMG mean amplitudes increased at fas ter treadmill speeds, and EMG burst durations shortened with decreased step cycl e durations. Muscle stretch of an ind ividual muscle could not account for the EM G amplitude modulation in response to stepping speed. The effects on the EMG amp litude and burst duration were similar in subjects with partial and no detectabl e supraspinal input. We propose that the human spinal cord can interpret complex steprelated, velocity dependent afferent information to contribute to the neur al control of stepping.