Year of Publication

2004

Document Type

Thesis

College

Graduate School

Department

Biomedical Engineering

First Advisor

Ranu Jung

Abstract

Rodent models are being extensively used to investigate the effects of traumatic injuryand to develop and assess the mechanisms of repair and regeneration. We presentquantitative assessment of 2D kinematics of overground walking and for the first time3D joint angle kinematics of all four limbs during treadmill walking in the intact and inincomplete spinal cord contusion injured (iSCI) adult female Long Evans rats. Phaserelationship between joint angles on a cycle-by-cycle basis and interlimb footfalls areassessed using a simple technique. Electromyogram (EMG) data from major flexor andextensor muscles for each of the hindlimb joints and elbow extensor muscles of theforelimbs synchronized to the 3D kinematics is also obtained in intact rats. EMG activityindicates specific relationships of the neural activity to joint angle kinematics. We findthat the ankle flexors as well as the hip and elbow extensors maintain constant burstduration with changing cycle duration. Overground walking kinematics providesinformation on stance width (SW), stride length (SL) and hindfoot rotation (Rot). SW andRot increased in iSCI rats. Treadmill walking kinematics provides information on jointangle trajectories. In iSCI rats double burst pattern in ankle angle as seen in intact ratsis lost and knee extension and range are reduced. Intra and interlimb coordination isimpaired. Left-right interlimb coordination and forelimb kinematics are not alteredsignificantly. In iSCI rats, maximum flexion of the knee during swing occurs in phasewith the hip as opposed to knee flexion preceeding hip flexion in intact rats. A mildexercise regimen in intact rats over eight weeks does not alter the kinematics.

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