Adolescent idiopathic scoliosis, is a complex three-dimensional deformity of the spine that affect pelvis and lower limb kinematics during primary movements of body including gait and trunk side bending. Multiple researches has have been conducted to analyse gait in scoliosis patients but most of this literature is relevant to lower limb kinematics kinetics and electromyography. Trunk biomechanics documentation is still lacking during gait and side bending movement.
The aim of this study was to elucidate biomechanical analysis including spatiotemporal parameters, kinematics, kinetics (joint moments and Ground Reaction Force (GRF), and electromyography of trunk segments and lower limb during gait and trunk side bending in adolescent idiopathic scoliosis patients with and without brace application, to find important parameters to implicate in 3-D printing brace design. In this study newly trunk mathematical model was designed by using Schroth anatomical blocks concept. Trunk was divided in upper thorax, middle thorax, lower thorax and lumber segments.
This study included three groups named as Control Group, Scoliosis Group (SG) and Scoliosis Group with Brace (SG WB) Participant from each group perform the same movements following the same experimental settings and protocols. After three-dimensional motion analysis of all the segments of trunk and lower limb, a comparison was made among the groups. Sagittal plane movement and frontal plane movements during level walking and trunk side bending was the targeted movements of this study. All the results were analysed by using Independent Samples Test to compare CG and SG. Because of small sample size SG WB group was not included in statistical analysis.
There was significant asymmetry noticed with p=0.02 for step velocity in two groups. All segment movements were not significantly different in SG than CG. However, Hip joint showed reduced range of motion (ROM) during Right Gait Cycle (RGC) and Left Gait Cycle (LGC). Trunk joint angle at maximum peak value in frontal plane showed significant difference (p=0.036 and p=0.023) at Right Toe off (RTO) during RGC and Right Heel Strike (RHS) during (LGC), respectively, trunk moved away from the thoracic apex side. Joint moments also showed some significant difference with p<0.05 during gait cycle.
Maximum Trunk Bending (MTB) in Right Side Bending (RSB) and Left Side Bending (LSB) was significantly less in SG than CG. Joint moment did not reveal noticeable difference between these two groups during side bending movement.
In this study there was not any finding for GRF statistically significant during level walking and side bending movement, but very slight difference was observed during level walking in medio-lateral direction of GRF. Electromyography pattern (EMG) for side bending movement was different and influenced by brace application in advantage and disadvantage of patient treatment. Integrated Electromyography (iEMG) of muscles including external oblique, erector spine and qudratus lumborum showed the difference in their activation.
Certain significant differences were observed between CG, SG and SG WB. These biomechanical findings will be assisting to design 3D printing scoliosis brace that would be able to reverse patho-biomechanics of three dimensional spine deformity.
Key Words: Scoliosis Bio-mechanical analysis, Brace effects in scoliosis, Trunk and lower limb bio-mechanics, Brace design and bio-mechanics

Adolescent idiopathic scoliosis, is a complex three-dimensional deformity of the spine that affect pelvis and lower limb kinematics during primary movements of body including gait and trunk side bending. Multiple researches has have been conducted to analyse gait in scoliosis patients but most of this literature is relevant to lower limb kinematics kinetics and electromyography. Trunk biomechanics documentation is still lacking during gait and side bending movement.
The aim of this study was to elucidate biomechanical analysis including spatiotemporal parameters, kinematics, kinetics (joint moments and Ground Reaction Force (GRF), and electromyography of trunk segments and lower limb during gait and trunk side bending in adolescent idiopathic scoliosis patients with and without brace application, to find important parameters to implicate in 3-D printing brace design. In this study newly trunk mathematical model was designed by using Schroth anatomical blocks concept. Trunk was divided in upper thorax, middle thorax, lower thorax and lumber segments.
This study included three groups named as Control Group, Scoliosis Group (SG) and Scoliosis Group with Brace (SG WB) Participant from each group perform the same movements following the same experimental settings and protocols. After three-dimensional motion analysis of all the segments of trunk and lower limb, a comparison was made among the groups. Sagittal plane movement and frontal plane movements during level walking and trunk side bending was the targeted movements of this study. All the results were analysed by using Independent Samples Test to compare CG and SG. Because of small sample size SG WB group was not included in statistical analysis.
There was significant asymmetry noticed with p=0.02 for step velocity in two groups. All segment movements were not significantly different in SG than CG. However, Hip joint showed reduced range of motion (ROM) during Right Gait Cycle (RGC) and Left Gait Cycle (LGC). Trunk joint angle at maximum peak value in frontal plane showed significant difference (p=0.036 and p=0.023) at Right Toe off (RTO) during RGC and Right Heel Strike (RHS) during (LGC), respectively, trunk moved away from the thoracic apex side. Joint moments also showed some significant difference with p<0.05 during gait cycle.
Maximum Trunk Bending (MTB) in Right Side Bending (RSB) and Left Side Bending (LSB) was significantly less in SG than CG. Joint moment did not reveal noticeable difference between these two groups during side bending movement.
In this study there was not any finding for GRF statistically significant during level walking and side bending movement, but very slight difference was observed during level walking in medio-lateral direction of GRF. Electromyography pattern (EMG) for side bending movement was different and influenced by brace application in advantage and disadvantage of patient treatment. Integrated Electromyography (iEMG) of muscles including external oblique, erector spine and qudratus lumborum showed the difference in their activation.
Certain significant differences were observed between CG, SG and SG WB. These biomechanical findings will be assisting to design 3D printing scoliosis brace that would be able to reverse patho-biomechanics of three dimensional spine deformity.
Key Words: Scoliosis Bio-mechanical analysis, Brace effects in scoliosis, Trunk and lower limb bio-mechanics, Brace design and bio-mechanics

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