Paraplegic users of mechanical walking orthoses, e.g. advanced reciprocating gait orthosis (ARGO), often face high energy expenditure and extreme upper body loading during locomotion. We studied the effect of kinematical pattern on the mechanical performance of paraplegic locomotion, in search for an improved gait pattern that leads to lower muscular efforts. A three-dimensional, four segment, six-degrees-of-freedom skeletal model of the advanced reciprocating gait orthosis-assisted paraplegic locomotion was developed based on the data acquired from an experimental study on a single subject. The effect of muscles was represented by ideal joint torque generators. A response surface analysis was performed on the model to determine the impact of the kinematical parameters on the resulting muscular efforts, characterized by net joint torques. Results indicated that a lateral bending manoeuvre at the trunk would facilitate the foot clearance by reducing the torque requirement of the whole body lateral tilting. For swing leg advancement, the trunk posterior bending manoeuvre was found to be more effective and efficient than the whole body axial rotation, owing to the coupled reciprocal action of the advanced reciprocating gait orthosis. It was hypothesized that a modified gait pattern, with larger trunk movements and no axial rotation, could improve the energy expenditure and upper body loading during advanced reciprocating gait orthosis-assisted locomotion. More detailed modelling and experimental studies are needed to verify this hypothesis and evaluate its potential effects on the soft tissue strains.

Adolescent idiopathic scoliosis (AIS) is an abnormal 3-dimensional curvature of the spine that appears in youth. In progressive cases, a small curve may be augmented rapidly and leads the victim to a high-risk surgical operation. Recognition of the AIS in the early stage can help in treating it with noninvasive methods. The goal of the study was to examine the relationship between intervertebral disc morphology and AIS as an applicable index and useful method for developing the screening and recognition of AIS before the start of disease. Based on a biomechanical model, we examined the relationship between AIS and intervertebral disc morphology in the thoracic and lumbar region separately and comparatively. For this purpose, the mean disc height (MDH) in the thoracic (MDHT) and lumbar (MDHL) regions and mean ratio of disc height per vertebral radius (MDHPVR) in the thoracic (MDHPVRT) and lumbar (MDHPVRL) regions were compared between 20 girls with AIS and 20 normal girls as the control group by using magnetic resonance imaging. Although there was a significant difference between the AIS and control group in MDHT (P = .004) and MDHPVRT (P = .006), this difference was more significant in the lumbar region (MDHL, P < .0001, and MDHPVRL, P < .0001). According to obtained results, the relation of MDHPVR and scoliosis can be established and used to develop as a screening method for diagnosis and treatment of adolescents who are exposed to scoliosis disorder at an early stage.

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Purpose: The effect of different flooring on sole somatosensory and the resulting changes on the dynamic balance of people while walking have interested researchers, as the motor control response in the elderly is the particular importance as a risk factor. Therefore, in this study, the effect of different floor coverings on friction as well as temporal and spatial parameters of walking in the elderly have been analyzed and evaluated in order to prevent slipping and falling. Methods: In this study, 22 elderly people over 60 years of age without a history of falling participated in this experiment. Each participant with a selected speed walked on three surfaces including the control surface (CO), soft spongy (FL) and plastic patterned (SF) non-slip flooring. The amount of ground reaction forces were recorded by force plates and kinematic data by VICON capture motion. Maximum shear force friction coefficient values (COFoMSF) in the anterior–posterior and medio-lateral directions in two consecutive stance phases and gait variables including the normalized length of step and stride, width of step, time of step and stride, as well as average velocity of step length and stride were measured. Results: No significant difference was observed between different levels in the value of friction coefficients [Formula: see text], but the friction coefficient of the maximum shear force in the anterior–posterior direction, step width and normalized step length in hard and patterned surfaces (SF & CO) compared to the soft sponge flooring (FL) decreased considerably. The results showed a significant correlation between the friction coefficient of the maximum shear force in the anterior–posterior direction with the velocity, width and duration of the step and stride only in the soft spongy flooring. Conclusion: The results of this study can help to better understand the design and level of surface adhesion in order to improve dynamic balance and reduce the risk of falling and possible failure in the elderly. In addition, it suggests the necessity of further investigation and the use of auxiliary exercises to improve and increase stability.