Kinematic and EMG Determinants in Quadrupedal Locomotion of a Non-Human Primate (Rhesus)

Abstract

. Kinematic and EMG determinants in quadrupedal locomotion of a non-human primate (Rhesus). J Neurophysiol 93: 3127-3145, 2005. First published January 12, 2005 doi:10.1152/jn.01073.2004. We hypothesized that the activation patterns of flexor and extensor muscles and the resulting kinematics of the forelimbs and hindlimbs during locomotion in the Rhesus would have unique characteristics relative to other quadrupedal mammals. Adaptations of limb movements and in motor pool recruitment patterns in accommodating a range of treadmill speeds similar to other terrestrial animals in both the hindlimb and forelimb were observed. Flexor and extensor motor neurons from motor pools in the lumbar segments, however, were more highly coordinated than in the cervical segments. Unlike the lateral sequence characterizing subprimate quadrupedal locomotion, non-human primates use diagonal coordination between the hindlimbs and forelimbs, similar to that observed in humans between the legs and arms. Although there was a high level of coordination between hind-and forelimb locomotion kinematics, limb-specific neural control strategies were evident in the intersegmental coordination patterns and limb endpoint trajectories. Based on limb kinematics and muscle recruitment patterns, it appears that the hindlimbs, and notably the distal extremities, contribute more to body propulsion than the forelimbs. Furthermore, we found adaptive changes in the recruitment patterns of distal muscles in the hind-and forelimb with increased treadmill speed that likely correlate with the anatomical and functional evolution of hand and foot digits in monkeys. Changes in the properties of both the spinal and supraspinal circuitry related to stepping, probably account for the peculiarities in the kinematic and EMG properties during non-human primate locomotion. We suggest that such adaptive changes may have facilitated evolution toward bipedal locomotion.

Combination treatment with chondroitinase ABC in spinal cord injury—breaking the barrier

“…A battery of behavioral tests has been developed in the past decades to study movement function after SCi. Kinematic analysis gives detailed information about locomotor control, and software tools are available to quantify limb movements [42,43] .…”

Animal Models of Neurologic Disorders: A Nonhuman Primate Model of Spinal Cord Injury

“…In primates, many studies have evaluated functional recovery after spinal cord transection [28][29][30][31], mostly using lesions of specific funiculi to determine the role of ascending [32][33][34][35] and descending tracts, especially the corticospinal tract [12,13,[36][37][38][39][40]. In initial studies we used a low thoracic (T10) hemisection to study the effect of a unilateral corticospinal tract lesion on quadrupedal stepping and recovery of fine motor control of the hindlimbs using tasks that required dexterous foot digit movements [41,42]. Because the most common site of human SCI is the cervical spinal cord, and sprouting or regeneration of axons for short distances beyond a cervical lesion could restore hand function, we continued model development using a C7 (spinal cord level) lateral hemisection SCI.…”

“…Kinematics and electrophysiological data were collected periodically from treadmill training and in the testing chair (baseline, 6, 9, 12, 16, 20, and 24 weeks postoperatively), and approximately once per month in the open field. For electrophysiological studies, bipolar intramuscular electromyography (EMG) electrodes (Konigsberg Instruments Inc., Pasadena, CA) were implanted into selected muscles for telemetric recording at 1 to 5 months prior to spinal cord hemisection [41,42]. For kinematics analyses, reflective markers were attached bilaterally to the shaved skin overlying the greater trochanter, the knee joint, the malleolus, the fifth metatarsal, and the outside tip of the fifth digit, the head of the humerus, the elbow joint, the distal head of the ulna, the metacarpophalangeal joint, and the outside tip of the third digit.…”

“…For kinematics analyses, reflective markers were attached bilaterally to the shaved skin overlying the greater trochanter, the knee joint, the malleolus, the fifth metatarsal, and the outside tip of the fifth digit, the head of the humerus, the elbow joint, the distal head of the ulna, the metacarpophalangeal joint, and the outside tip of the third digit. SIMI motion capture software (SIMI Reality Motion Systems, Unterschleissheim, Germany) was used to obtain threedimensional coordinates of the markers synchronized with EMG output [41,42,45].…”

“…Initial studies performed during development of this model were aimed at discerning unique characteristics of locomotion in the Rhesus monkey compared to other quadrupedal mammals [41], and at determining how a low thoracic corticospinal tract lesion would affect quadrupedal stepping in the monkey [42]. These studies were performed to create a primate model of SCI that produced persistent deficits in locomotion and fine motor control, and in which neural repair interventions could be tested.…”