BIOMECHANICAL ANALYSIS OF SWING-THROUGH GAIT IN PARAPLEGIC AND NONDISABLED INDIVIDUALS

The purpose of this study was to determine if the deficit of motor fun ction affects the displacement of the lower limbs and increases the ph ysical strain of upper-body musculature in paraplegic individuals perf orming swing-through gait. A biomechanical model consisting of four li nked rigid bodies was developed to analyze this type of gait. Data wer e obtained on the spatio-temporal characteristics, kinematics and kine tics from a sample of eight non-disabled and nine paraplegic individua ls performing swing-through gait. Net muscle moments acting on the seg ments and mechanical powers at three joints (shedder, elbow, hip) were estimated during a complete gait cycle from basic force equations and moments of force acting on a rigid body. Results show that the two gr oups selected a similar comfortable speed suggesting that the type of gait per se is an important factor in the selection of speed. Parapleg ic individuals had a longer crutch stance phase duration than the non- disabled due to inadequate hip muscle activations as confirmed by the moment of force and power analyses. Moreover, a higher moment of force at the shoulder was observed in the paraplegics individuals, mostly d uring the crutch stance phase. Consequently, the loss of motor functio n of the lower limbs in paraplegic individuals modifies the biomechani cal pattern of swing-through gait compared to non-disabled individuals , and seems to increase the physiological demand on the upper limbs du ring the stance and swing phases of the gait cycle.