Proximal and distal motor nerve conduction in obturator and femoral nerves

To study the proximal and distal motor conduction properties of obturator and femoral nerves.

For evaluation of distal motor conduction properties, obturator and femoral nerves were stimulated at the inguinal ligament, and M responses were recorded with needle electrodes from gracilis and rectus femoris muscles. Upper lumbar roots were stimulated with needle electrodes inserted between L1-L2 vertebral laminae.

Sixteen healthy adults, eight of each gender, age 22 to 52 years (mean 37.5).

Description of a method for assessing motor conduction along the obturator nerve and evaluating proximal motor conduction measurements obtained with stimulation of obturator and femoral nerves.

Distal motor conduction latencies were 3.9 +/- 0.7 msec for gracilis and 4.6 +/- 0.5msec for rectus femoris after stimulation of obturator and femoral nerves, respectively. Proximal conduction times from lumbar vertebral level were 10.4 +/- 0.3msec for the obturator nerve and 10.8 +/- 0.4msec for the femoral nerve. Conduction velocities of proximal segments of both nerves were similar, 62m/sec for the obturator nerve and 65m/sec for the femoral nerve. Submaximal stimulation of both nerves evoked H-reflex responses from their associated muscles.

Motor conduction properties of the obturator nerve can be assessed by the method described, particularly to differentiate between peripheral, plexus, or radicular lesions that involve the obturator nerve.